![earthquakes which in that year alarmed the inhabitants of Leghorn.
About the same time the Rev. S. Chandler, writing about the shock at
Lisbon, tells us that earthquakes may be measured by means of a
spherical bowl about three or four feet in diameter, the inside of
which, after being dusted over with Barber’s puff, is filled very gently
with water. Mallet, Babbage, and De la Bêche have recommended
the same sort of contrivance, but, notwithstanding, it has justly been
criticised as ‘ridiculous and utterly impracticable.’[7]
An important portion of Palmieri’s well-known instrument consists
of horizontal tubes turned up at the ends and partially filled with
mercury. To magnify the motion of the mercury, small floats of iron
rest on its surface. These are attached by means of threads to a
pulley provided with indices which move in front of a scale of
degrees. We thus read off the intensity of an earthquake as so many
degrees, which means so many millimetres of washing up and down
of mercury in a tube. The direction of movement is determined by
the azimuth of the tube which gives the maximum indication, several
tubes being placed in different azimuths.
This form of instrument appears to have been suggested by
Mallet, who gives an account of the same in 1846. Inasmuch as the
rise and fall of the mercury in such tubes depend on its depth and
on the period of the earthquake together with its duration, we see
that although the results obtained from a given instrument may give
us means of making approximate comparisons as to the relative
intensity of various earthquakes, it is very far from yielding any
absolute measurement.
Another method which has been employed to magnify and register
the motions of liquid in a vessel has been to float upon its surface a
raft or ship from which a tall mast projected. By a slight motion of
the raft, the top of the mast vibrated through a considerable range.
This motion of the mast as to direction and extent was then
recorded by suitable contrivances attached to the top of the mast.
A very simple form of liquid seismoscope consists of a circular
trough of wood with notches cut round its side. This is filled with](https://image.slidesharecdn.com/41516-250416234618-5a12e47a/85/Proteomics-Methods-and-Protocols-1st-Edition-Friedrich-Lottspeich-Auth-29-320.jpg)
![CHAPTER III.
EARTHQUAKE MOTION DISCUSSED THEORETICALLY.
Ideas of the ancients (the views of Travagini, Hooke, Woodward, Stukeley,
Mitchell, Young, Mallet)—Nature of elastic waves and vibrations—Possible
causes of disturbance in the Earth’s crust—The time of vibration of an earth
particle—Velocity and acceleration of a particle—Propagation of a disturbance
as determined by experiments upon the elastic moduli of rocks—The intensity
of an earthquake—Area of greatest overturning moment—Earthquake waves—
Reflexion, refraction, and interference of waves—Radiation of a disturbance.
Ideas of Early Writers.—One of the first accounts of the varieties
of motion which may be experienced at the time of an earthquake is
to be found in the classification of earthquakes given by Aristotle.[8]
It is as follows:—
1. Epiclintæ, or earthquakes which move the ground obliquely.
2. Brastæ, with an upward vertical motion like boiling water.
3. Chasmatiæ, which cause the ground to sink and form hollows.
4. Rhectæ, which raise the ground and make fissures.
5. Ostæ, which overthrow with one thrust.
6. Palmatiæ, which shake from side to side with a sort of tremor.
From the sixth group in this classification we see that this early
writer did not regard earthquakes as necessarily isolated events, but
that some of them consisted of a succession of backward and
forward vibratory motions. He also distinguishes between the total
duration of an earthquake and the length of, and intervals between,
a series of shocks. Aristotle had, in fact, some idea of what modern
writers upon ordinary earthquakes would term ‘modality.’
The earliest writer who had the idea that an earthquake was a
pulse-like motion propagated through solid ground appears to have
been Francisci Travagini, who, in 1679, wrote upon an earthquake](https://image.slidesharecdn.com/41516-250416234618-5a12e47a/85/Proteomics-Methods-and-Protocols-1st-Edition-Friedrich-Lottspeich-Auth-50-320.jpg)
Proteomics Methods and Protocols 1st Edition Friedrich Lottspeich (Auth.)
- 1. Proteomics Methods and Protocols 1st Edition Friedrich Lottspeich (Auth.) pdf download https://ebookfinal.com/download/proteomics-methods-and- protocols-1st-edition-friedrich-lottspeich-auth/ Explore and download more ebooks or textbooks at ebookfinal.com
- 2. We have selected some products that you may be interested in Click the link to download now or visit ebookfinal.com for more options!. Membrane Proteomics Methods and Protocols 1st Edition Henry Bigelow https://ebookfinal.com/download/membrane-proteomics-methods-and- protocols-1st-edition-henry-bigelow/ Clinical Proteomics Methods and Protocols 2nd Edition Antonia Vlahou https://ebookfinal.com/download/clinical-proteomics-methods-and- protocols-2nd-edition-antonia-vlahou/ Renal and Urinary Proteomics Methods and Protocols 1st Edition Visith Thongboonkerd https://ebookfinal.com/download/renal-and-urinary-proteomics-methods- and-protocols-1st-edition-visith-thongboonkerd/ Cancer Genomics and Proteomics Methods and Protocols 1st Edition Narendra Wajapeyee (Eds.) https://ebookfinal.com/download/cancer-genomics-and-proteomics- methods-and-protocols-1st-edition-narendra-wajapeyee-eds/
- 3. Plant Proteomics Methods and Protocols 1st Edition Valérie Méchin https://ebookfinal.com/download/plant-proteomics-methods-and- protocols-1st-edition-valerie-mechin/ Quantitative Methods in Proteomics 1st Edition Katharina Podwojski https://ebookfinal.com/download/quantitative-methods-in- proteomics-1st-edition-katharina-podwojski/ Vagabond Vol 29 29 Inoue https://ebookfinal.com/download/vagabond-vol-29-29-inoue/ Dengue Methods and Protocols 1st Edition Radhakrishnan Padmanabhan https://ebookfinal.com/download/dengue-methods-and-protocols-1st- edition-radhakrishnan-padmanabhan/ Immunoproteomics Methods and Protocols 1st Edition Scott Mccomb https://ebookfinal.com/download/immunoproteomics-methods-and- protocols-1st-edition-scott-mccomb/
- 5. Proteomics Methods and Protocols 1st Edition Friedrich Lottspeich (Auth.) Digital Instant Download Author(s): Friedrich Lottspeich (auth.), Jörg Reinders, Albert Sickmann (eds.) ISBN(s): 9781607611561, 1607611562 Edition: 1 File Details: PDF, 5.52 MB Year: 2009 Language: english
- 7. For other titles published in this series, go to www.springer.com/series/7651 ME T H O D S I N MO L E C U L A R BI O L O G Y ™ Series Editor John M. Walker School of Life Sciences University of Hertfordshire Hatfield, Hertfordshire, AL10 9AB, UK
- 8. Proteomics Methods and Protocols Edited by Jörg Reinders* and Albert Sickmann† *UniversityofRegensburg,InstituteofFunctionalGenomics,Joseph-EngertStrasse993053 Regensburg,Germany † InstitutfϋrSpektrochemieundAngewandteSpektroskopie(ISAS),Bunsen-KirchoffStr.1144139 Dortmund,Germany
- 9. ISSN: 1064-3745 e-ISSN: 1940-6029 ISBN: 978-1-60761-156-1 e-ISBN: 978-1-60761-157-8 DOI: 10.1007/978-1-60761-157-8 Springer Dordrecht Heidelberg London New York Library of Congress Control Number: 2009927501 © Humana Press, a part of Springer Science+Business Media, LLC 2009 All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Humana Press, c/o Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is for-bidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com) Editors Jörg Reinders University of Regensburg Institute of Functional Genomics Joseph-Engert-Strasse 9 93053 Regensburg Germany Albert Sickmann Institut für Spektrochemie und Angewandte Spektroskopie (ISAS) Bunsen-Kirchoff Str. 11 44139 Dortmund Germany
- 10. v Preface Proteins are essential players in all cellular processes, facilitating various functions as enzymes and structure-forming or signal-transducing molecules. Their enormous versa- tility in primary structure, folding, and modification enables a complex, highly dynamic, but nevertheless robust, network carrying out all the necessary tasks to ensure proper function of each cell and concerted activity of cellular associations up to complex organ- isms. Therefore, proteins have always been, and presumably will always be, the target of all kinds of studies in biological sciences. Protein purification and separation methods have a longstanding record as they were a prerequisite for enzymological studies and chemical protein identification methods such as Edman-sequencing. Thus, various elaborate and mostly time-consuming techniques for the isolation of distinct proteins have been developed often based on chromatography or electrophoresis, and the identification of the protein’s primary structure was accomplished afterwards by no less intricate methods. However, the relatively recent development of MALDI- and ESI-ionization techniques for mass spectrometric analysis of large and frag- ile biomolecules enabled protein identification in an automated fashion, thereby speeding up protein identification by a multiple. This turned out to be a major breakthrough in protein analysis enabling high-throughput protein identification on a global scale, leading to approaches to study the entirety of all proteins of a cell, tissue, organ, etc. In 1995, the term “Proteome” was introduced by Marc Wilkins and Keith Wil- liams as the entirety of all proteins encoded in a single genome expressed under distinct conditions representing the turning point in the journey from studying genes to studying proteins, from “Genomics” to “Proteomics.” Since then, great efforts have been under- taken to characterize a “healthy” or a “diseased” proteome, but it soon turned out that a proteome is far too complex and dynamic to be defined by such simple terms. The enor- mous progress that has been accomplished both technically and biologically has not only granted deeper insight into the cellular network but has also raised further questions and set further challenges to proteomic research. The enormous range of protein abundance, dynamics, and interactions as well as the spatio-temporal distribution of a proteome gave rise to the evolution of several new fields like phospho-, glyco-, subcellular, and membrane proteomics, etc. Many techniques have been developed or significantly increased in these fields and will contribute to the under- standing of the cellular networks in the future. Leading scientists have contributed to this volume, which is intended to give an over- view of the contemporary challenges and possibilities in the various areas of proteomics and to offer some detailed protocols as examples for successful analysis in proteomics studies. Therefore, we hope that this book can raise your interest in proteomics and be a valuable reference book for your laboratory work. v
- 11. vii Contents Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Contributors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix PART I INTRODUCTION 1. Introduction to Proteomics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Friedrich Lottspeich PART II ELECTROPHORETIC SEPARATIONS 2. High-Resolution Two-Dimensional Electrophoresis . . . . . . . . . . . . . . . . . . . . . . 13 Walter Weiss and Angelika Görg 3. Non-classical 2-D Electrophoresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Jacqueline Burré, Ilka Wittig, and Hermann Schägger 4. Protein Detection and Quantitation Technologies for Gel-Based Proteome Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Walter Weiss, Florian Weiland, and Angelika Görg PART III MASS SPECTROMETRY AND TANDEM MASS SPECTROMETRY APPLICATIONS 5. MALDI MS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Rainer Cramer 6. Capillary Electrophoresis Coupled to Mass Spectrometry for Proteomic Profiling of Human Urine and Biomarker Discovery . . . . . . . . . . . 105 Petra Zürbig, Eric Schiffer, and Harald Mischak 7. A Newcomer’s Guide to Nano-Liquid-Chromatography of Peptides . . . . . . . . . . 123 Thomas Fröhlich and Georg J. Arnold 8. Multidimensional Protein Identification Technology . . . . . . . . . . . . . . . . . . . . . . 143 Katharina Lohrig and Dirk Wolters 9. Characterization of Platelet Proteins Using Peptide Centric Proteomics . . . . . . . . 155 Oliver Simon, Stefanie Wortelkamp, and Albert Sickmann 10. Identification of the Molecular Composition of the 20S Proteasome of Mouse Intestine by High-Resolution Mass Spectrometric Proteome Analysis . . . . 173 Reinhold Weber, Regina Preywisch, Nikolay Youhnovski, Marcus Groettrup, and Michael Przybylski PART IV QUANTITATIVE PROTEOMICS 11. Liquid Chromatography–Mass Spectrometry-Based Quantitative Proteomics. . . . 189 Michael W. Linscheid, Robert Ahrends , Stefan Pieper, and Andreas Kühn
- 12. 12. iTRAQ-Labeling of In-Gel Digested Proteins for Relative Quantification . . . . . . 207 Carla Schmidt and Henning Urlaub 13. Electrospray Mass Spectrometry for Quantitative Plasma Proteome Analysis . . . . 227 Hong Wang and Sam Hanash PART V INTERPRETATION OF MASS SPECTROMETRY DATA 14. Algorithms and Databases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 Lennart Martens and Rolf Apweiler 15. Shotgun Protein Identification and Quantification by Mass Spectrometry . . . . . . 261 Bingwen Lu, Tao Xu, Sung Kyu Park, and John R. Yates III PART VI ANALYSIS OF PROTEIN MODIFICATIONS 16. Proteomics Identification of Oxidatively Modified Proteins in Brain . . . . . . . . . . 291 Rukhsana Sultana, Marzia Perluigi, and D. Allan Butterfield 17. Isotope-Labeling and Affinity Enrichment of Phosphopeptides for Proteomic Analysis Using Liquid Chromatography–Tandem Mass Spectrometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303 Uma Kota, Ko-yi Chien, and Michael B. Goshe PART VII SUBCELLULAR PROTEOMICS 18. Organelle Proteomics: Reduction of Sample Complexity by Enzymatic In-Gel Selection of Native Proteins . . . . . . . . . . . . . . . . . . . . . . . . 325 Veronika Reisinger and Lutz A. Eichacker 19. Isolation of Plasma Membranes from the Nervous System by Countercurrent Distribution in Aqueous Polymer Two-Phase Systems . . . . . . 335 Jens Schindler and Hans Gerd Nothwang 20. Enrichment and Preparation of Plasma Membrane Proteins from Arabidopsis thaliana for Global Proteomic Analysis Using Liquid Chromatography–Tandem Mass Spectrometry . . . . . . . . . . . . . . . . 341 Srijeet K. Mitra, Steven D. Clouse, and Michael B. Goshe PART VIII ANALYSIS OF PROTEIN INTERACTIONS 21. Tandem Affinity Purification of Protein Complexes from Mammalian Cells by the Strep/FLAG (SF)-TAP Tag . . . . . . . . . . . . . . . . . 359 Christian Johannes Gloeckner, Karsten Boldt, Annette Schumacher, and Marius Ueffing 22. Sequential Peptide Affinity Purification System for the Systematic Isolation and Identification of Protein Complexes from Escherichia coli . . . . . . . . . . . . . . . 373 Mohan Babu, Gareth Butland, Oxana Pogoutse, Joyce Li, Jack F. Greenblatt, and Andrew Emili 23. Bioinformatical Approaches to Detect and Analyze Protein Interactions. . . . . . . . 401 Beate Krüger and Thomas Dandekar Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433 viii Contents
- 13. Contributors ROBERT AHRENDS • Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor Str. 2, 12489 Berlin, Germany ROLF APWEILER • EMBL Outstation – Hinxton, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK GEORG J. ARNOLD • Laboratory for Functional Genome Analysis LAFUGA, Gene Center, Ludwig-Maximilians-University Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany MOHAN BABU • Banting and Best Department of Medical Research, University of Toronto, Donnelly Center for Cellular and Biomolecular Research, 160 College Street, Toronto, Ontario, Canada M5S 3E1 KARSTEN BOLDT • Department of Protein Science, Helmholtz Zentrum München, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany; Institute of Human Genetics, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany; Helmholtz Zentrum München – German Research Center for Environmental Health, Department of Protein Science, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany JACQUELINE BURRÉ • Department of Neuroscience, The University of Texas Southwestern Medical Center, 6000 Harry Hines Boulevard, Dallas, TX, 75390-911, USA GARETH BUTLAND • Banting and Best Department of Medical Research, University of Toronto, Donnelly Center for Cellular and Biomolecular Research, 160 College Street, Toronto, Ontario, Canada M5S 3E1; Life Science Division, Lawrence Berkeley National Lab, 1 Cyclotron Road MS 84R0171, Berkeley, CA 94720 D. ALLAN BUTTERFIELD • Department of Chemistry, Center of Membrane Sciences, and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055, USA KO-YI CHIEN • Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695-7622, USA STEVEN D. CLOUSE • Department of Horticultural Science, North Carolina State University, Raleigh, NC 27695-7609, USA RAINER CRAMER • The BioCentre and Department of Chemistry, The University of Reading, Whiteknights, Reading, RG6 6AS, UK THOMAS DANDEKAR • Bioinformatik, Biozentrum, Am Hubland, 97074 Universitaet Wuerzburg, Germany LUTZ A. EICHACKER • Universitetet i Stavanger, Centre for Organelle Research, Kristine-Bonnevisvei 22, 4036 Stavanger, Norway ix
- 14. ANDREW EMILI • Banting and Best Department of Medical Research, University of Toronto, Donnelly Centre for Cellular and Biomolecular Research, 160 College Street, Toronto, Ontario, Canada M5S 3E1 THOMAS FRÖHLICH • Laboratory for Functional Genome Analysis LAFUGA, Gene Center, Ludwig-Maximilians-University Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany CHRISTIAN JOHANNES GLOECKNER • Department of Protein Science, Helmholtz Zentrum München – German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany ANGELIKA GÖRG • Technische Universität München (TUM), Life Science Center Weihenstephan (WZW), Area: Proteomics, Am Forum 2, 85350 Freising-Weihenstephan, Germany MICHAEL B. GOSHE • Department of Molecular and Structural Biochemistry, North Carolina State University, 128 Polk Hall, Campus Box 7622, Raleigh NC 27695-7622, USA JACK F. GREENBLATT • Banting and Best Department of Medical Research, University of Toronto, Donnelly Center for Cellular and Biomolecular Research, 160 College Street, Toronto, Ontario, Canada M5S 3E1; Department of Medical Genetics and Microbiology, University of Toronto, 1 King’s College Circle, Toronto, Ontario, Canada M5S 1A8 MARCUS GROETTRUP • Division of Immunology, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany SAM HANASH • Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N., M5-C800, P.O. Box 19024, Seattle, WA 98109, USA UMA KOTA • Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695-7622, USA BEATE KRÜGER • Bioinformatik, Biozentrum, Am Hubland, 97074 Universitaet Wuerzburg, Germany ANDREAS KÜHN • Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor Str. 2, 12489 Berlin, Germany JOYCE LI • Banting and Best Department of Medical Research, University of Toronto, Donnelly Center for Cellular and Biomolecular Research, 160 College Street, Toronto, Ontario, Canada M5S 3E1 MICHAEL W. LINSCHEID • Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor Str. 2, 12489 Berlin, Germany KATHARINA LOHRIG • Department of Analytical Chemistry, Ruhr-University Bochum, Universitaetsstr. 150, 44780 Bochum, Germany FRIEDRICH LOTTSPEICH • Protein Analytics, Max-Planck-Institute of Biochemistry, Martinsried, Germany BINGWEN LU • Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA LENNART MARTENS • EMBL Outstation – Hinxton, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK x Contributors
- 15. Contributors xi HARALD MISCHAK • Mosaiques diagnostics GmbH, Mellendorfer Str. 7-9, 30625 Hannover, Germany SRIJEET K. MITRA • Department of Horticultural Science, North Carolina State University, Raleigh, NC 27695-7609, USA HANS GERD NOTHWANG • Abteilung Neurogenetik, Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität, 21111 Oldenburg, Germany ROBIN PARK • Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA MARZIA PERLUIGI • Department of Biochemical Sciences, University of Rome “La Sapienza”, 00185, Rome, Italy STEFAN PIEPER • Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor Str. 2, 12489 Berlin, Germany OXANA POGOUTSE • Banting and Best Department of Medical Research, University of Toronto, Donnelly Center for Cellular and Biomolecular Research, 160 College Street, Toronto, Ontario, Canada M5S 3E1 REGINA PREYWISCH • Division of Immunology, Department of Biology, University of Konstanz, Konstanz, Germany MICHAEL PRZYBYLSKI • Department of Chemistry, Laboratory of Analytical Chemistry and Biopolymer Structure Analysis, University of Konstanz, 78457 Konstanz, Germany VERONIKA REISINGER • Universitetet i Stavanger, Centre for Organelle Research, Kristine-Bonnevisvei 22, 4036 Stavanger, Norway HERMANN SCHÄGGER • Molekulare Bioenergetik, Zentrum der Biologischen Chemie, Fachbereich Medizin, Universität Frankfurt, Theodor-Stern-Kai 7, Haus 26, D-60590 Frankfurt am Main, Germany ERIC SCHIFFER • Mosaiques diagnostics GmbH, Mellendorfer Str. 7-9, 30625 Hannover, Germany JENS SCHINDLER • Abteilung Neurogenetik, Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität, 21111 Oldenburg, Germany CARLA SCHMIDT • Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany ANNETTE SCHUMACHER • Department of Protein Science, Helmholtz Zentrum München, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany ALBERT SICKMANN • Institut für Spektrochemie und Angewandte Spektroskopie (ISAS), Bunsen-Kirchoff Str. 11 44139 Dortmund, Germany OLIVER SIMON • Rudolf-Virchow-Center, DFG-Research Center for Experimental Biomedicine, Wuerzburg, Germany RUKHSANA SULTANA • Department of Chemistry, Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA MARIUS UEFFING • Department of Protein Science, Helmholtz Zentrum München, Ingolstaedter Landstr. 1, 85764 Neuherberg, Germany; Institute of Human Genetics, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- 16. HENNING URLAUB • Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany HONG WANG • Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA REINHOLD WEBER • Laboratory of Analytical Chemistry and Biopolymer Structure Analysis, Department of Chemistry, University of Konstanz, Konstanz, Germany FLORIAN WEILAND • Fachgebiet Proteomik, Technische Universität München, Freising-Weihenstephan, Germany WALTER WEISS • Technische Universität München, Fachgebiet Proteomik, Am Forum 2, D-85350 Freising-Weihenstephan, Germany ILKA WITTIG • Molekulare Bioenergetik, Zentrum der Biologischen Chemie, Centre of Excellence “Macromolecular Complexes”, Fachbereich Medizin, Johann Wolfgang Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany DIRK WOLTERS • Department of Analytical Chemistry, Ruhr-University Bochum, Universitaetsstr. 150, 44780 Bochum, Germany STEFANIE WORTELKAMP • Institut für Spektrochemie und Angewandte Spektroskopie (ISAS), Bunsen-Kirchoff Str. 11 44139 Dortmund, Germany TAO XU • Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA JOHN R. YATES III • Department of Chemical Physiology, The Scripps Research Institute, SR11, 10550 North Torrey Pines Rd., La Jolla, CA 92037, USA NIKOLAY YOUHNOVSKI • Laboratory of Analytical Chemistry and Biopolymer Structure Analysis, Department of Chemistry, University of Konstanz, Konstanz, Germany; Algorithme Pharma Inc., Montreal, Montreal H7V 4B4, Canada PETRA ZÜRBIG • Mosaiques diagnostics GmbH, Mellendorfer-Str. 7-9, 30625 Hannover, Germany xii Contributors
- 17. Chapter 1 Introduction to Proteomics Friedrich Lottspeich Summary In this chapter, the evolvement of proteomics from classical protein chemistry is depicted. The challenges of complexity and dynamics led to several new approaches and to the firm belief that a valuable proteomics technique has to be quantitative. Protein-based vs. peptide-based techniques, gel-based vs. non-gel-based proteomics, targeted vs. general proteomics, isotopic labeling vs. label-free techniques, and the importance of informatics are summarized and compared. A short outlook into the near future is given at the end of the chapter. Key words: History, Quantitative proteomics, Targeted proteomics, Isotopic labeling, Protein-based proteomics, Peptide-based proteomics In the end of the last century, a change of paradigm from the pure function driven biosciences to systematic and holistic approaches has taken place. Following the successful genomics projects, classical protein chemistry has evolved into a high throughput and systematic science, called proteomics. Starting in 1995, the first attempts to deliver a “protein complement of the genome” used the established high-resolving separation techniques like two-dimensional (2D) gel electrophoresis and almost exclusively identified the proteins by the increasingly powerful mass spectrometry. Soon, fundamental and technical challenges were recognized. Unlike the genome, the proteome is dynamic, responding to any change in genetic and environmental parameters. Furthermore, the proteome appears to be orders of magnitude more complex than a genome owing to splicing and 1. The History and the Challenge Jörg Reinders and Albert Sickmann (eds.), Proteomics, Methods in Molecular Biology, Vol. 564 DOI: 10.1007/978-1-60761-157-8_1, © Humana Press, a part of Springer Science+Business Media, LLC 2009 3
- 18. 4 Lottspeich editing processes at the RNA level and owing to all the post- translational events on the protein level, like limited processing, post-translational modifications, and degradation. The situation is even more difficult, since many important proteins are only present in a few copies/cells and have to be identified and quantified in the presence of a large excess of many other proteins. The dynamic range of the abundant and the minor proteins often exceeds the capabilities of all analytical methods. So far, only few solutions are available to handle the com- plexity and dynamic range. One is to reduce the complexity of the proteome and to separate the low abundant proteins from the more abundant ones. This, for example, can be achieved by multidimensional separation steps. But, unpredictable losses of proteins and a large number of resulting fractions make this approach time-consuming and thus also very costly. Alternatively, the proteome to be investigated can be simplified by starting with a specific biological compartment or by reducing the complexity using a suitable sample preparation (e.g. enzyme ligand chips, functionalized surface chips, class-specific antibodies). Successful examples are the analysis of functional complexes or most inter- action proteomics approaches. In another approach, a selective detection is performed, which visualizes only a certain number of proteins that exhibit specific common properties. This can be achieved by antibodies, selective staining protocols, protein lig- ands, or selective mass spectrometry techniques like MRM (mul- tiple reaction monitoring) or SRM (single reaction monitoring) (1). The most straightforward application of this approach is “targeted proteomics,” which monitors a small set of well-known proteins/peptides. However, in the later years of the past century, the main focus of proteomics projects was to decipher the constituents of a proteome. It was realized only slowly that for solving biological problems and realizing the potential of holistic approaches, the changes and the dynamics of changes on the protein level have to be monitored quantitatively. Since 1975 by their introduction in by O’Farrel (2) and Klose (3), 2D gels have fascinated many scientists owing to their sep- aration power. The combination of a concentrating technique, i.e. isoelectric focusing, with a separation according to molecular mass, i.e. SDS gel electrophoresis, provides a space for resolving more than 10,000 different compounds. Consequently, 2D gels were the method of choice when dealing with very complex protein 2. Gel-Based Proteomics
- 19. Introduction to Proteomics 5 mixtures like proteomes. Unfortunately, gel-based proteomics had inherent limitations in reproducibility and dynamic range. Standard operating procedures had to be carefully followed to get almost reproducible results even within one lab. Results pro- duced from identical samples in different labs were hardly com- parable on a quantitative level. A significant improvement was the introduction of the DIGE technique (GE Healthcare), a multi- plexed fluorescent Cy-Dye staining of different proteome states, which eliminated to a large extent the technical irreproducibility (4). With the cysteine-modifying “DIGE saturation labeling,” impressive proteome visualization can be achieved with only a few micrograms of starting material (5). A disadvantage is that only two different fluorescent reagents are commercially available for “complete DIGE” and the costs of the reagents are rather prohibitive for larger proteomics projects. Additionally, limita- tions in load capacity, quantitative reproducibility, difficulties in handling, and interfacing problems to mass spectrometry limited the analysis depth and comprehensiveness of the gel-based pro- teomics studies. How to overcome the limitations of gels and at the same time keep the advantages of a concentrating separation mode like iso-electric focusing? Several instruments were developed that are able to separate proteins in solution but nevertheless use a focusing technique. Probably, the most recognized realizations of these concepts are free-flow electrophoresis instruments like “Octopus” (Becton Dickinson) and the “Off-Gel” system (Agi- lent). Undoubtedly, when these rather new systems are compared with 2D gels, distinct advantages in recovery and improvements in the amount that can be applied have been realized, but inter- facing to a further separation dimension is hampered by rather large volumes and buffer constituents. Thus, the resolution of 2D gels had not been reached so far. In the near future, technical and applicative improvements are to be expected to partly over- come some of the limitations. In the limited landscape of separation methods, chromatography seemed to have the potential as an alternative tool for in-depth proteome analysis. However, from classical protein chemistry, it was well known that proteins did not give quantitative recovery in many chromatographic modes. So far, only one non-gel mul- tidimensional approach based on chromatographic methods was commercially realized. In the “ProteomeLabTM PF-2D” system 3. Seeking Alternatives 3.1. Non-Gel-Based Electrophoresis 3.2. Chromatography
- 20. 6 Lottspeich (Beckman), a chromatofocusing column coupled with a reversed phase chromatography fractionates the sample into more than 1,000 fractions. However, here also the advantage to keep the proteins in solution is compromised with the fact that the resolu- tion of the fully chromatographic solution is considerably lower than that with 2D gels. Thus, since obviously quantitative multidimensional separations of proteins proved to be notoriously difficult, other alternatives were searched for. One conceptual new idea was to transfer the separation and quantification problem from the protein to the peptide level. If this could be achieved, a new dimension of speed, automation, and reproducibility can be obtained. Thus, new peptide-based strategies, e.g. MudPIT (6), were developed where after cleaving the proteome into peptides, highly automated mul- tidimensional liquid chromatography separations were followed by identification of the peptides using tandem mass spectro- metry. Mainly owing to this switch to peptide-based proteomics, chromatography experienced a new boom, and miniaturiztion of peptide separation columns to diameters below 100 µm and introduction of instruments that were capable to deliver nano- liter flow rates became available. Nano-LC with online or off-line mass spectrometric detection became routine. However, in mul- tidimensional mode, nano-LC is still on the border of technical practicability and it still suffers from lack of robustness and ease of handling. With the application of the peptide-based proteomics strate- gies, several severe disadvantages became obvious. By cleaving the proteins into peptides, not only the complexity of the proteome was increased by tenfold, but important information concerning the protein identification was also destroyed. Many peptides are identically found in functionally completely different proteins. Thus, from a peptide, the progenitor usually cannot be deduced unequivocally. Furthermore, different isoforms, post-translationally modified proteins, or processing and degradation products of a protein, all produce a large set of identical peptides. As a result, the quantitative information for a certain protein becomes quite uncertain. Amounts of a peptide that are present in more than one protein species do not reflect the quantity of a single protein species, but rather the quantity of the sum of all protein species that contain this peptide. Due to the complexity and the necessity to analyze and iden- tify each peptide by tandem mass spectrometry, proteome analysis time and costs increased markedly. Strictly speaking, today even the most rapid mass spectrometers are not able to analyze in detail all the masses present in one LC run. Therefore, often especially minor peptides are not analyzed. This so-called “undersampling” is certainly one of the reasons for the usually bad reproducibility 3.3. Peptide-Based Proteomics
- 21. Introduction to Proteomics 7 of proteome studies, where often a simple repetition of the analy- sis gives only 20%–30% of overlapping data. As a consequence of all these aspects, reduction of complexity in quantitative proteomics should be done at protein level. The behavior of a protein during a separation is a characteristic parameter and should also be used for detailed identification and discrimination of single protein species. To improve the quantitative proteomics results, “isotope labe- ling” techniques were introduced. These “isotopic dilution” strategies were already well known for the analysis of small mole- cules, drugs, and metabolites. The pioneering work to introduce this technique into the proteomics field was done by the Aeber- sold group, where the cysteine residues in all proteins of two pro- teomic states were modified with a biotin-containing either heavy or light version of a reagent (isotope coding affinity tag, ICAT® ) (7). Then, the labeled proteomes were combined and cleaved into peptides. Only the cysteine-containing peptides carrying the label are isolated by affinity purification using streptavidin. Peptide separation and mass analysis revealed the identity of the peptides and at the same time determined by the signal intensity of the isotopic peptide pair the quantitative ratio of the peptides in the original proteomes. Improved versions of isotopic reagents were developed, e.g. isotope coding protein label, ICPL® (Serva), small amino group reactive reagents, which gave better reaction yields and increased sequence coverage (8). Of course, an introduction of the isotopic label as early as possible is desirable, since all the steps performed without the isotopic control may contribute to quantitatively wrong results. Therefore, introducing the isotopic label at an even earlier stage of a proteome analysis was developed. Culture media enriched with N15 isotopes or stable isotope labeling of amino acids in cell culture (SILAC) was used in proteomics experiments, espe- cially in cell culture or with microorganisms (9). However, with a remarkable effort, a “SILAC mouse” was also generated and used in proteomics experiments (10). The metabolic labeling approaches are usually restricted to cell culture experiments and are not applicable to samples from higher organisms (e.g. body fluids, tissues, etc.) Also, for peptide-based approaches, a number of isotopic rea- gents were proposed. The most popular is iTRAQ (ABI), a family of eight isobaric amino group reactive reagents (11). Because of the identical mass of all variants of the reagent, a certain peptide 4. Quantitative Proteomics Using Stable Isotopic Labeling
- 22. 8 Lottspeich derived from different proteome states will appear with the identical mass and thus - in contrast to non-isobaric isotopic reagents – the labeling does not increase the complexity in the mass spec- trum. However, with a simple, cheap, and rapid MS analysis, no quantitative data can be obtained. Only during MS/MS analysis, specific reporter ions for the different reagents will be liberated and can be quantified. To produce quantitative correct results, the mass selected for MS/MS analysis has to be rather pure. This often is not the case in crowded chromatograms. Consequently, the advantages of high multiplexing with isobaric reagents are somewhat diminished by the limitation to rather low complex peptide mixtures and by the task to analyze each derivatized pep- tide by MS/MS analysis to disclose quantitative results. One of the major difficulties in larger proteomics projects is the enormous amount of data that will be produced. Tens of thousands of mass spectra from each proteomic state can be analyzed only by using automated software solutions. Because of demanding peak detection in overcrowded spectra and challenging peptide/protein identification and the mere amount of data to be processed today, data analysis and data evaluation is by far the most time-consuming part of a proteome analysis. Software for automatically detecting the interesting proteins that change from one proteome state to another and filtering such proteins out of the complex proteome data can be expected in the near future. However, So far many proteomics experiments published did not really deliver solid and valuable scientific content. This partly is connected with the idea of holistic approaches per se, that the observation of the reactions of a perturbed system does not neces- sarily provide a simple and clear answer, but rather is a hypothesis generating concept. Unfortunately, the technical ability to cope with proteome complexity is still very limited despite the amaz- ing technical progresses in mass spectrometry and nanosepara- tions. Consequently, it is often tried to analyze a proteome with significant effort, time, and money, though with today’s analyt- ics, most of the existing proteins are out of reach. Only a fraction of the proteome can be explored and to judge the significance 5. Informatics and Data Mining 6. State of the Art and Future
- 23. Introduction to Proteomics 9 and validity of the results, biological and statistical repetitions of the experiments are scientifically required. However, because of the large effort and high costs, this is often ignored. The danger is that in the long run, by ignoring good scientific praxis, the reli- ability of proteomics as an analytical technique may be queried. Therefore, we are forced to elaborate intelligent and sophisti- cated strategies to obtain valid and valuable biological information with the existing technologies in sample preparation, separation sciences, mass spectrometry, and informatics. Closest to this goal is probably “targeted proteomics.” Already today, this approach is able to monitor hundreds of known proteins quantitatively and sensitively and it will gain increasing acceptance and eventually enter routine clinical diagnostics. With general comparative proteomics in attempting the holistic concept, the situation is more complicated with general comparative proteomics. Neither analysis depth nor quantitative accuracy is satisfactory today. Post-translational modifications and analysis of many different protein species originating from the same gene present major difficulties in high throughput approaches and require innovative strategies. Isotopic labeling techniquesareincompetitionwithlabel-freetechniques.Although label-free approaches have demonstrated amazingly good results with simple protein mixtures, they have to substantiate this at the proteomics level and after multidimensional separation steps also. Most of the problems and shortcomings are recognized and many scientists are working on their solutions. After one dec- ade of rapid improvements in analysis techniques and only slight improvement in the separation field, the acute pressure is now on the further development in separation sciences. Integrated, well–designed, and highly automated workflows using both chromatography and electrophoresis will be necessary to solve the ambitious proteomics separation problem. Novel separation strategies and interfacing solutions of highly automated multidi- mensional fractionation schemes are a challenging research area and will, to a large extent, determine the success of proteomics as a holistic approach in the future. References 1. Anderson L., Hunter C.L. (2006) Quantitative mass spectrometric multiple reaction monitor- ing assays for major plasma proteins. Mol. Cell. Proteomics 5, 573–588. 2. O’Farrell P.H. (1975) High resolution two- dimensional electrophoresis of proteins. J. Biol. Chem. 250, 4007–4021. 3. Klose J. (1975) Protein mapping by combined isoelectric focusing and electrophoresis of mouse tissues A novel approach to testing for induced point mutations in mammals. Human- genetik 26, 231–243. 4. Unlue M., Morgan M.E., Minden J.S. (1997) Difference gel electrophoresis: A single gel method for detecting changes in protein extracts. Electrophoresis 18, 2071–2077. 5. Sitek B., Luettges J., Marcus K., Kloeppel G., Schmiegel W., Meyer H.E., Hahn S.A., Stuehler K. (2005) Application of fluorescence difference gel electrophoresis saturation labelling for the analysis of microdissected precursor lesions of pancreatic ductal adenocarcinoma. Proteomics 5(10), 2665–2679. 6. Washburn M.P., Wolters D., Yates J.R. 3rd (2001) Large-scale analysis of the yeast
- 24. 10 Lottspeich proteome by multidimensional protein identifi- cation technology. Nat.Biotechnol. Mar; 19(3), 242–277. 7. Gygi S.P., Rist B., Gerber S.A., Turecek F., Gelb H.M., Aebersold R. (1999) Quantita- tive analysis of complex protein mixtures using isotope-coded affinity tags. Nat.Biotechnol. 17, 994–999. 8. Schmidt A., Kellermann J., Lottspeich F. (2005) A novel strategy for quantitative proteomics using isotope-coded protein labels. Proteomics 5, 4–15. 9. Ong S.E., Blagoev B., Kratchmarova I., Kris- tensen D.B., Steen H., Pandey A., Mann M. (2002) Stable isotope labeling by amino acids in cell culture, SILAC, as a simple and accurate approach to expression proteomics. Mol. Cell. Proteomics 1, 376–386. 10. Krueger M., Moser M., Ussar S., Thievessen I., Luber C., Forner F., Schmidt S., Zaniva S., Fässler R., Mann M. (2008) SILAC-mouse for quantitative proteome analysis uncovers Kindlin-3 as an essential factor for red blood cell function. Cell. Jul 25; 134(2), 353–364. 11. Ross P.L., Huang Y.N., Marchese J.N., Wil- liamson B., Parker K., Hattan S., Khainovski N., Pillai S., Dey S., Daniels S., Purkayastha S., Juhasz P., Martin S., Bartlet-Jones M., He F., Jacobson A., Pappin D.J. (2004) Multiplexed protein quantitation in Saccharomyces cerevisiae using amine-reactive isobaric tagging reagents. Mol. Cell. Proteomics 3, 1154–1169.
- 25. Chapter 2 High-Resolution Two-Dimensional Electrophoresis Walter Weiss and Angelika Görg Summary Two-dimensional gel electrophoresis (2-DE) with immobilized pH gradients (IPGs) combined with protein identification by mass spectrometry is currently the workhorse for the majority of ongoing proteome projects. Although alternative/complementary technologies, such as MudPIT, ICAT, or protein arrays, have emerged recently, there is up to now no technology that matches 2-DE in its ability for routine parallel expression profiling of large sets of complex protein mixtures. 2-DE delivers a map of intact proteins, which reflects changes in protein expression level, isoforms, or post-translational modifications. High-resolution 2-DE can resolve up to 5,000 proteins simultaneously (∼2,000 proteins routinely), and detect and quantify <1 ng of protein per spot. Today’s 2-DE technology with IPGs has largely overcome the former limitations of carrier ampholyte-based 2-DE with respect to reproducibility, handling, resolution, and separation of very acidic or basic proteins. Current research to further advance 2-DE technology has focused on improved solubilization/separation of hydrophobic proteins, display of low abundance proteins, and reliable protein quantitation by fluorescent dye technologies. Here, we provide a comprehensive protocol of the current high-resolution 2-DE technology with IPGs for proteome analysis and describe in detail the individual steps of this technique, i.e., sample preparation and protein solubilization, isoelectric focusing in IPG strips, IPG strip equilibration, and casting and running of multiple SDS gels. Last but not the least, a section on how to circumvent the major pitfalls is included. Key words: Immobilized pH gradient, Proteome, Two-dimensional electrophoresis Two-dimensional electrophoresis (2-DE) couples isoelectric focusing (IEF) in the first dimension and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) in the second dimension to separate proteins according to two independent parameters, i.e., isoelectric point (pI) in the first dimension and 1. Introduction Jörg Reinders and Albert Sickmann (eds.), Proteomics, Methods in Molecular Biology, Vol. 564 DOI: 10.1007/978-1-60761-157-8_2, © Humana Press, a part of Springer Science+Business Media, LLC 2009 13
- 26. Discovering Diverse Content Through Random Scribd Documents
- 27. the instrument are still to be seen in Tokio. These instruments consist of a piece of magnetic iron ore, which holds up a piece of iron like a nail. This nail is connected, by means of a string, with a train of clockwork communicating with an alarm. If the nail falls a catch is released and the clockwork set in motion, and warning given by the ringing of a bell. It does not appear that this instrument has ever acted with success. Columns.—One of the commonest forms of seismoscope, and one which has been very widely used, consists of a round column of wood, metal, or other suitable material, placed, with its axis vertical, on a level plane, and surrounded by some soft material such as loose sand to prevent it rolling should it be overturned. The fall of such a column indicates that a shaking or shock has taken place. Attempts have been made by using a number of columns of different sizes to make these indications seismometric, but they seldom give reliable information either as to intensity or direction of shock. The indications as to intensity are vitiated by the fact that a long- continued gentle shaking may overturn a column which would stand a very considerable sudden shock, while the directions in which a number of columns fall seldom agree owing to the rotational motion imparted to them by the shaking. Besides, the direction of motion of the earthquake seldom remains in the same azimuth throughout the whole disturbance. An extremely delicate, and at the same time simple form of seismoscope may be made by propping up strips of glass, pins, or other easily overturned bodies against suitably placed supports. In this way bodies may be arranged, which, although they can only fall in one direction, nevertheless fall with far less motion than is necessary to overturn any column which will stand without lateral support. Projection Seismometers.—Closely related to the seismoscopes and seismometers which depend on the overturning of bodies. Mallet has described two sets of apparatus whose indications depend on the distance to which a body is projected. In one of these, which
- 28. consisted of two similar parts arranged at right angles, two metal balls rest one on each side of a stop at the lower part of two inclined like troughs. In this position each of the balls completes an electric circuit. By a shock the balls are projected or rolled up the troughs, and the height to which they rise is recorded by a corresponding interval in the break of the circuits. The vertical component of the motion is measured by the compression of a spring which carries the table on which this arrangement rests. In the second apparatus two balls are successively projected, one by the forward swing, and the other by the backward swing of the shock. Attached to them are loose wires forming terminals of the circuits. They are caught in a bed of wet sand in a metal trough forming the other end of the circuit. The throw of the balls as measured in the sand, and the difference of time between their successive projections as indicated by special contrivances connected with the closing of the circuits, enables the observer to calculate the direction of the wave of shock, its velocity, and other elements connected with the disturbance. It will be observed that the design of this apparatus assumes the earthquake to consist of a distinct isolated shock. Oldham, at the end of his account of the Cachar earthquake of 1869, recommends the use of an instrument based on similar principles. In his instrument four balls like bullets are placed in notches cut in the corners of the upper end of a square stake driven into the ground. Vessels filled with liquid.—Another form of simple seismoscope is made by partially filling a vessel with liquid. The height to which the liquid is washed up the side of the vessel is taken as an indication of the intensity of the shock, and the line joining the points on which maximum motion is indicated, is taken as the direction of the shock. If earthquakes all lasted for the same length of time, and consisted of vibrations of the same period, such instruments might be of service. These instruments have, however, been in use from an early date. In 1742 we find that bowls of water were used to measure the
- 29. earthquakes which in that year alarmed the inhabitants of Leghorn. About the same time the Rev. S. Chandler, writing about the shock at Lisbon, tells us that earthquakes may be measured by means of a spherical bowl about three or four feet in diameter, the inside of which, after being dusted over with Barber’s puff, is filled very gently with water. Mallet, Babbage, and De la Bêche have recommended the same sort of contrivance, but, notwithstanding, it has justly been criticised as ‘ridiculous and utterly impracticable.’[7] An important portion of Palmieri’s well-known instrument consists of horizontal tubes turned up at the ends and partially filled with mercury. To magnify the motion of the mercury, small floats of iron rest on its surface. These are attached by means of threads to a pulley provided with indices which move in front of a scale of degrees. We thus read off the intensity of an earthquake as so many degrees, which means so many millimetres of washing up and down of mercury in a tube. The direction of movement is determined by the azimuth of the tube which gives the maximum indication, several tubes being placed in different azimuths. This form of instrument appears to have been suggested by Mallet, who gives an account of the same in 1846. Inasmuch as the rise and fall of the mercury in such tubes depend on its depth and on the period of the earthquake together with its duration, we see that although the results obtained from a given instrument may give us means of making approximate comparisons as to the relative intensity of various earthquakes, it is very far from yielding any absolute measurement. Another method which has been employed to magnify and register the motions of liquid in a vessel has been to float upon its surface a raft or ship from which a tall mast projected. By a slight motion of the raft, the top of the mast vibrated through a considerable range. This motion of the mast as to direction and extent was then recorded by suitable contrivances attached to the top of the mast. A very simple form of liquid seismoscope consists of a circular trough of wood with notches cut round its side. This is filled with
- 30. mercury to the level of the notches. At the time of an earthquake the maximum quantity of mercury runs over the notches in the direction of greatest motion. This instrument, which has long been used in Italy, is known as a Cacciatore, being named after its inventor. It is a prominent feature in the collection of apparatus forming the well-known seismograph of Palmieri. Pendulum instruments.—Mallet speaks of pendulum seismoscopes and seismographs as ‘the oldest probably of seismometers long set up in Italy and southern Europe.’ In 1841 we find these being used to record the earthquake disturbances at Comrie in Scotland. These instruments may be divided into two classes: first, those which at the time of the shock are intended to swing, and thus record the direction of movement; and second, those which are supposed to remain at rest and thus provide ‘steady points.’ To obtain an absolutely ‘steady point’ at the time of an earthquake, has been one of the chief aims of all recent seismological investigations. With a style or pointer projecting down from the steady point to a surface which is being moved backward and forward by the earth, such a surface has written upon it by its own motions a record of the ground to which it is attached. Conversely, a point projecting upwards from the moving earth might be caused to write a record on the body providing the steady point, which in the class of instruments now to be referred to is supposed to be the bob of a pendulum. It is not difficult to get a pendulum which will swing at the time of a moderately strong earthquake, but it is somewhat difficult to obtain one which will not swing at such a time. During the past few years, pendulums varying between forty feet in length and carrying bobs of eighty pounds in weight, and one-eighth of an inch in length, and carrying a gun-shot, have been experimented with under a great variety of circumstances. Sometimes the supports of these pendulums have been as rigid as it is possible to make a structure from brick and mortar, and at other times they have intentionally been made loose and flexible. The indices which wrote
- 31. the motions of these pendulums have been as various as the pendulums themselves. A small needle sliding vertically through two small holes, and resting its lower end on a surface of smoked glass, has on account of its small amount of friction been perhaps one of the favourite forms of recording pointers. The free pendulums which have been employed, and which were intended to swing, have been used for two purposes: first, to determine the direction of motion from the direction of swing, and second, to see if an approximation to the period of the earth’s motion could be obtained by discovering the pendulum amongst a series of different lengths which was set in most violent motion, this probably being the one which had its natural period of swing the most nearly approximating to the period of the earthquake oscillations. Inasmuch as all pendulums when swinging have a tendency to change the plane of their oscillation, and also as we now know that the direction of motion during an earthquake is not always constant, the results usually obtained with these instruments respecting the direction of the earth’s motion have been unsatisfactory. The results which were obtained by series of pendulums of different lengths were, for various reasons, also unsatisfactory. Of pendulums intended to provide a steady point, from which the relative motion of a point on the earth’s surface could be recorded, there has been a great variety. One of the oldest forms consisted of a pendulum with a style projecting downwards from the bob so as to touch a bed of sand. Sometimes a concave surface was placed beneath the pendulum, on which the record was traced by means of a pencil. Probably the best form was that in which a needle, capable of sliding freely up and down, marked the relative horizontal motion of the earth and the pendulum bob on a smoked glass plate. It generally happens that at the time of a moderately severe earthquake the whole of these forms of apparatus are set in motion, due partly to the motion of the point of support of the pendulum, and partly to the friction of the writing point on the plate.
- 32. Among these pendulums may be mentioned those of Cavallieri, Faura, Palmieri, Rossi, and numerous others. It is possible that the originators of some of these pendulums may have intended that they should record by swinging. If this is so, then so far as the determination of the actual nature of earthquake motion is concerned, they belong to a lower grade of apparatus than that in which they are here included. A great improvement in pendulum apparatus is due to Mr. Thomas Gray of Glasgow, who suggested applying so much frictional resistance to the free swing of a pendulum that for small displacements it became ‘dead beat.’ By carrying out this suggestion, pendulum instruments were raised to the position of seismographs. The manner of applying the friction will be understood from the following description of a pendulum instrument which is also provided with an index which gives a magnification of the motion of the earth. b b b b is a box 113 cm. high and 30 cm. by 18 cm. square. Inside this box a lead ring r, 17 cm. in diameter and 3 cm. thick, is suspended as a pendulum from the screw s. This screw passes through a small brass plate p p, which can be moved horizontally over a hole in the top of the box. These motions in the point of suspension allow the pendulum to be adjusted. Projecting over the top of the pendulum there is a wooden arm w carrying two sliding pointers h h, resting on a glass plate placed on the top of the pendulum. These pointers are for the purpose of giving the frictional resistance before referred to. If this friction plate is smoked, the friction pointers will write upon it records of large earthquakes independently of the records given by the proper index, which only gives satisfactory records in the case of shocks of ordinary intensity. Crossing the inside of the pendulum r there is a brass bar perforated with a small conical hole at m. A stiff wire passes through m and forms the upper portion of the index i, the lower portion of which is a thin piece of bamboo. Fixed upon the wire there is a small brass ball which rests on the upper side of a
- 33. Fig. 2. second brass plate also perforated with a conical hole, which plate is fixed on the bar o o crossing the box. If at the time of an earthquake the upper part of the index i remains steady at m, then by the motion at o, the lower end of the index which carries a sliding needle at g, will magnify the motion of the earth in the ratios m o : o g. In this instrument o g is about 17 cm. The needle g works upon a piece of smoked glass. In order to bring the glass into contact with the needle without disturbance, the glass is carried on a strip of wood k, hinged at the back of the box, and propped up in front by a loose block of wood y. When y is removed the glass drops down with k out of contact with the needle. The box is carried on bars of wood c c, which are fixed to the ground by the stakes a a. The great advantage of a pendulum seismograph working on a stationary plate is, that the record shows at once whether the direction of motion has been constant, or whether it has been variable. The maximum extent of motion in various directions is also easily obtained. The disadvantage of the instrument is, that at the time of a large earthquake, owing perhaps to a slight swing in the pendulum, the records may be unduly magnified.
- 34. On such occasions, however, fairly good records may be obtained from the friction pointers, provided that the plates on which they work have been previously smoked. It might perhaps be well to use two of these instruments, one having a comparatively high frictional resistance, and hence ‘dead beat’ for large displacements. Many attempts have been made to use a pendulum seismograph in conjunction with a record-receiving surface, which at the time of the earthquake should be kept in motion by clockwork. In this way it was hoped to separate the various vibrations of the earthquake, and thus avoid the greater or less confusion which occurs when the index of the pendulum writes its backward and forward motion on a stationary plate. Hitherto all attempts in this direction, in which a single multiplying index was used, have been unsuccessful because of the moving plate dragging the index in the direction of its motion for a short distance, and then allowing it to fall back towards its normal position. In connection with this subject we may mention the pendulum seismographs of Kreil, Wagener, Ewing, and Gray. In the bob of Kreil’s pendulum there was clockwork, which caused a disc on the axis of the pendulum to continuously rotate. On this continually revolving surface a style fixed to the earth traced an unbroken circle. At the time of an earthquake, by the motion of the style, the circle was to be broken and lines drawn. The number and length of these lines were to indicate the length and intensity of the disturbance. Gray’s pendulum consisted of a flat heavy disc carrying on its upper surface a smoked glass plate. This, which formed the bob of the pendulum, was supported by a pianoforte steel wire. When set ready to receive an earthquake, the wire was twisted and the bob held by a catch so arranged that at the time of the earthquake the catch was released, and the bob of the pendulum allowed to turn slowly by the untwisting of the supporting wire. Resting on the surface of this rotating disc were two multiplying indices arranged to write the earth’s motions as two components.
- 35. In the instruments of Wagener and Ewing, the clockwork and moving surface do not form part of the pendulum, but rest independently on a support rigidly attached to the earth. In Wagener’s instrument one index only is used, while in Ewing’s two are used for writing the record of the motion. A difficulty which is apparent in all pendulum machines is that when the bob of such a pendulum is deflected it tends to fall back to its normal position. To make a pendulum perfect it therefore requires some compensating arrangement, so that the pendulum, for small displacements, shall be in neutral equilibrium, and the errors due to swinging shall be avoided. Several methods have been suggested for making the bob of an ordinary pendulum astatic for small displacements. One method proposed by Gray consists in fixing in the bob of a pendulum a circular trough of liquid, the curvature of this trough having a proper form. Another method which was suggested, was to attach a vertical spiral spring to a point in the axis of the pendulum a little below the point of suspension, and to a fixed point above it, so that when the pendulum is deflected it would introduce a couple. Professor Ewing has suggested an arrangement so that the bob of the pendulum shall be partly suspended by a stretched spiral spring, and at the same time shall be partly held up from below by a vertically placed strut, the weight carried by the strut being to the weight carried by the spring in the ratio of their respective lengths. As to how these arrangements will act when carried into practice yet remains to be seen. Another important class of instruments are inverted pendulums. These are vertical springs made of metal or wood loaded at their upper end with a heavy mass of metal. An arrangement of this sort, provided at its upper end with a pencil to write on a concave surface, was employed in 1841 to register the earthquakes at Comrie in Scotland. In Japan they were largely employed in series, each member of a series having a different period of vibration. The object of these arrangements was to determine which of the pendulums,
- 36. with a given earthquake, recorded the greatest motion, it being assumed that the one which was thrown into the most violent oscillation would be the one most nearly approximating with the period of the earthquake. The result of these experiments showed that it was usually those with a slow period of vibration which were the most disturbed. Bracket Seismographs.—A group of instruments of recent origin which have done good work, are the bracket seismographs. These instruments appear to have been independently invented by several investigators: the germ from which they originated probably being the well-known horizontal pendulum of Professor Zöllner. In Japan they were first employed by Professor W. S. Chaplin. Subsequently they were used by Professor Ewing and Mr. Gray. They consist essentially of a heavy weight supported at the extremity of a horizontal bracket which is free to turn on a vertical axis at its other end. When the frame carrying this axis is moved in any direction excepting parallel to the length of the gate-like bracket, the weight causes the bracket to turn round a line known as the instantaneous axis of the bracket corresponding to this motion of the fixed axis. Any point in this line may therefore be taken as a steady point for motions at right angles to the length of the supporting bracket. Two of these instruments placed at right angles to each other have to be employed in conjunction, and the motion of the ground is written down as two rectangular components. In Professor Ewing’s form of the instrument, light prolongations of the brackets form indices which give magnified representations of the motion, and the weights are pivoted round a vertical axis through their centre. In the accompanying sketch b is a heavy weight pivoted at the end of a small bracket c a k, which bracket is free to turn on a knife- edge, k, above, and a pivot a, below, in the stand s. At the time of an earthquake b remains steady, and the index p, forming a continuation of the bracket, magnifies the motion of the stand, in the ratio of a c : c n.
- 37. Fig. 4. Fig. 3. In an instrument called a double-bracket seismograph, invented by Mr. Gray, we have two brackets hinged to each other, and one of them to a fixed frame. The planes of the two brackets are placed at right angles, so as to give to a heavy mass supported at the end of the outer bracket two degrees of horizontal freedom. In all bracket machines, especially those which carry a pivoted weight, it is doubtful whether the weight provides a truly steady point relatively to the plate on which the record is written for motion parallel to the direction of the arm. Parallel motion Instrument.—A machine which writes its record as two components, and which promises great stability, is one suggested by Professor C. D. West. Like the bracket machines it consists of two similar parts placed at right angles to each other, and is as follows: A bar of iron a is suspended from both sides on pivots at c c by a system of light arms hinging with each other at the black dots, between the upper and lower parts of the rigid frame b c. The arms are of such a length that for small displacements parallel to the length of the bar, c c practically move in a straight line, and the bar is in neutral equilibrium. A light prolongation of the bar d works the upper end of the light index e, passing as a
- 38. universal joint through the rigid support f. A second index e′ from the bar at right angles also passes through f. The multiplying ends of these indices are coupled together to write a resultant motion on a smoked glass plate s. Conical Pendulums.—Another group of instruments which have also yielded valuable records are the conical pendulum seismographs. The idea of using the bob of a conical pendulum to give a steady point in an earthquake machine was first suggested and carried into practice by Mr. Gray. The seismograph as employed consists of a pair of conical pendulums hung in planes at right angles to each other. The bob of each of these pendulums is fixed a short distance from the end of a light lever, which forms the writing index, the short end resting as a strut against the side of a post fixed in the earth. The weight is carried by a thin wire or thread, the upper end of which is attached to a point vertically above the fixed end of the lever. Rolling Spheres and Cylinders.—After the conical pendulum seismographs, which claim several important advantages over the bracket machines, we come to a group of instruments known as rolling sphere seismographs. Here, again, we have a class of instruments for the various forms of which we are indebted to the ingenuity of Mr. Gray. The general arrangement and principle of one of these instruments will be readily understood from the accompanying figure. s is a segment of a large sphere with a centre near c. Slightly below this centre a heavy weight b, which may be a lead ring, is pivoted. At the time of an earthquake c is steady, and the earth’s motions are magnified by the pointer c a n in the proportion of c a : a n. The working of this pointer or index is similar to that of the pointer in the pendulum.
- 39. Fig. 5. Closely connected with the rolling sphere seismographs, are Gray’s rolling cylinder seismographs. These are two cylinders resting on a surface plate with their axes at right angles to each other. Near to the highest point in each of these cylinders, this point remaining nearly steady when the surface plate is moved backwards and forwards, there is attached the end of a light index. These indices are again pivoted a short distance from their ends on axes connected with the surface plate. In order that the two indices may be brought parallel, one is cranked at the second pivot. Ball and Plate Seismograph.—Another form of seismograph, which is closely related to the two forms of apparatus just described, is Verbeck’s ball and plate seismograph. This consists of a surface plate resting on three hard spheres, which in turn rests upon a second surface plate. When the lower plate is moved, the upper one tends to remain at rest, and thus may be used as a steady mass to move an index.
- 40. The Principle of Perry and Ayrton.—An instrument which is of interest from the scientific principle it involves is a seismograph suggested by Professors Perry and Ayrton, who propose to support a heavy ball on three springs, which shall be sufficiently stiff to have an exceedingly quick period of vibration. By means of pencils attached to the ball by levers, the motions of the ball are to be recorded on a moving band of paper. The result would be a record compounded of the small vibrations of the springs superimposed on the larger, slower, wave-like motions of the earthquake, and, knowing the former of these, the latter might be separated by analysis. Although our present knowledge of earthquake motion indicates that the analysis of such a record would often present us with insuperable difficulties, this instrument is worthy of notice on account of the novelty of the principle it involves, which, the authors truly remark, has in seismometry been a ‘neglected’ one. Instruments to record Vertical Motion.—The instruments which have been devised to record vertical motion are almost as numerous as those which have been devised to record horizontal motion. The earliest form of instrument employed for this purpose was a spiral spring stretched by weight, which, on account of its inertia, was supposed at the time of a shock to remain steady. No satisfactory results have ever been obtained from such instruments, chiefly on account of the inconvenience in making a spring sufficiently long to allow of enough elongation to give a long period of vibration. Similar remarks may be applied to the horizontally placed elastic rods, one end of which is fixed to a wall, whilst the opposite end is loaded with a weight. Such contrivances, furnished with pencil on the weight to write a record upon a vertical surface, were used in 1842 at Comrie, and we see the same principle applied in a portion of Palmieri’s apparatus. Contrivances like these neither give us the true amplitude of the vertical motion, insomuch as they are readily set in a state of oscillation; nor do they indicate the duration of a disturbance, for, being once set in motion, they continue that motion in virtue of their inertia long after the actual earthquake has ceased. They can only be regarded as seismoscopes.
- 41. Fig. 6. The most satisfactory instrument which has yet been devised for recording vertical motion is Gray’s horizontal lever spring seismograph. This instrument will be better understood from the accompanying sketch. A vertical spring s is fixed at its upper end by means of a nut n, which rests on the top of the frame f, and serves to raise or lower the spring through a short distance as a last adjustment for the position of the cross-arm a. The arm a rests at one end on two sharp points, p, one resting in a conical hole and the other in a v-slot; it is supported at b by the spring s, and is weighted at c with a lead ring r. Over a pin at the point c a stirrup of thread is placed which supports a small trough, t. The trough t is pivoted at a, has attached to it the index i (which is hinged by means of a strip of tough paper at h, and rests through a fine pin on the glass plate g), and is partly filled with mercury. Another method of obtaining a steady point for vertical motion is that of Dr. Wagener, who employs a buoy partly immersed in a vessel of water. This was considerably improved upon by Mr. Gray, who suggested the use of a buoy, which, with the exception of a long thin style, was completely sunk. Among the other forms of apparatus used to record vertical motion may be mentioned vessels provided with india-rubber or other flexible bottoms, and partially filled with water or some other liquid. As the vessel is moved up and down, the bottom tends to
- 42. remain behind and provides a more or less steady point. Pivoted to this is a light index, which is again pivoted to a rigid frame in connection with the earth. Instruments of this description have yielded good records. Record Receivers.—A large number of earthquake machines having been referred to, it now remains to consider the apparatus on which they write their motions. The earlier forms of seismographs, as has already been indicated, recorded their movements in a bed of sand; others wrote their records by means of pencils on sheets of paper. Where we have seismographs which magnify the motion of the earth, it will be observed that methods like the above would involve great frictional resistances, tending to cause motion in the assumed steady points of the seismographs. One of the most perfect instruments would be obtained by registering photographically the motions of the recording index by the reflection of a ray of light. Such an instrument would, however, be difficult to construct and difficult to manipulate. One of the best practical forms of registering apparatus is one in which the record is written on a surface of smoked glass. This can afterwards be covered with a coat of photographer’s varnish, and subsequently photographed by the ‘blue process’ so well known to engineers. To obtain a record of all the vibrations of an earthquake it is necessary that the surface on which the seismograph writes should at the time of an earthquake be in motion. Of record-receiving machines there are three types. First, there are those which move continuously. The common form of these is a circular glass plate like an old form of chronograph, driven continuously by clockwork. On this the pointers of the seismograph rest and trace over and over again the same circles. At the time of an earthquake they move back and forth across the circles, which are theoretically fine lines, and leave a record of the earthquake. Instead of a circular plate, a drum covered with smoked paper may be used, which, after the earthquake, possesses the advantage, after unrolling, of presenting the record in a straight line, instead of a record written round the periphery of a circle, as is the case with the circular glass plates.
- 43. Such records are easily preserved, but they are more difficult to photograph. The second form of apparatus is one which is set in motion at the time of a shock. This may be a contrivance like one of those just described, or a straight smoked glass plate on a carriage. By means of an electrical or a mechanical contrivance called a ‘starter,’ of which many forms have been contrived, the earthquake is caused to release a detent and thus set in motion the mechanism which moves the record receiver. The great advantage of continuously-moving machines is that the beginning and end of the shock can usually be got with certainty, while all the uncertainty as to the action of the ‘starter’ is avoided. Self-starting machines have, of course, the advantage of simplicity and cheapness, while there is no danger of the record getting obliterated by the subsequent motion of the plate under the index. Time-recording Apparatus.—Of equal importance with the instruments which record the motion of the ground, are those instruments which record the time at which such motion took place. The great value of time records, when determining the origin from which an earthquake originates, will be shown farther on. The most important result which is required in connection with time observations, is to determine the interval of time taken by a disturbance in travelling from one point to another. On account of the great velocity with which these disturbances sometimes travel, it is necessary that these observations should be made with considerable accuracy. The old methods of adapting an apparatus to a clock which, when shaken, shall cause the clock to stop, are of little value unless the stations at which the observations are made are at considerable distances apart. This will be appreciated when we remember that the disturbance may possibly travel at the rate of a mile per second, that its duration at any station may often extend over a minute, and that one set of apparatus at one station may stop, perhaps, at the commencement of the disturbance, and the other near the end. A satisfactory time-taking apparatus will
- 44. Fig. 7. therefore require, not only the means for stopping a clock, but also a contrivance which, at the same instant that the clock is stopped, shall make a mark on a record which is being drawn by a seismograph. In this way we find out at which portion of the shock the time was taken. Palmieri stops a clock in his seismograph by closing an electric circuit. Mallet proposes to stop a clock by the falling of a column which is attached by a string to the pendulum of the clock. So long as the column is standing the string is loose and the pendulum is free to move; but when the column falls, the string is tightened and the pendulum is arrested. The difficulty which arises is to obtain a column that will fall with a slight disturbance. The best form of contrivance for causing a column to fall, and one which may also be used in drawing out a catch to relieve the machinery of a record receiver, is shown in the accompanying sketch. s is the segment of a sphere about 4·5 cm. radius, with a centre slightly above c. l is a disc of lead about 7 cm. in diameter resting upon the segment. Above this there is a light pointer, p, about 30 cm. long. On the top of the pointer a small cylinder of iron, w, is balanced, and connected by a string with the catch to be relieved. When the table on which w p s rests is shaken, rotation takes place near to c, the motion of the base s is magnified at the upper end of the pointer, and the weight overturned. This catch may be used to relieve a toothed bar axled at one end, and held up above a pin projecting from the face of the pendulum bob. When this falls it catches the projecting pin and holds the pendulum.
- 45. Another way of relieving the toothed bar is to hold up the opposite end to that at which it is axled by resting it on the extremity of a horizontal wire fixed to the bob of a conical pendulum—for example, one of the indices of a conical pendulum seismograph. The whole of this apparatus, which may be constructed at the cost of a few pence, can be made small enough to go inside an ordinary clock case. The difficulty which arises with all these clock-stopping arrangements is that it is difficult for observers situated at distant stations to re-start their clocks so that their difference in time shall be accurately known. Even if each observer is provided with a well- regulated chronometer, with which he can make comparisons, the rating of these instruments is for all ordinary persons an extremely troublesome operation. In order to avoid this difficulty the author has of late years used a method of obtaining the time without stopping the clock. To do this a clock with a central seconds hand is taken, and the hour and minute hands are prolonged and bent out slightly at their extremities at right angles to the face, the hour hand being slightly the longest. Each hand is then tipped with a piece of soft material like cork, which is smeared with a glycerine ink. A light flat ring, with divisions in it corresponding to those on the face of the clock, is so arranged that at the time of a shock it can be quickly advanced to touch the inked pads on the hands of the clock and then withdrawn. This is accomplished by suitable machinery, which is relieved either by an electro-magnet or some other contrivance which will withdraw a catch. In this way an impression in the form of three dots is received on the disc, and the time known without either stopping or sensibly retarding the clock. For ordinary observers, if a time-taker is not used in conjunction with a record receiver, as good results as those obtained by ordinary clock-stopping apparatus are obtainable by glancing at an ordinary watch. Subsequently the watch by which the observation was made
- 46. should be compared with some good time-keeper, and the local time at which the shock took place is then approximately known. From what has now been said it will be seen that for a complete seismograph we require three distinct sets of apparatus—an apparatus to record horizontal motion, an apparatus to record vertical motion, and an apparatus to record time. The horizontal and vertical motions must be written on the same receiver, and if possible side by side, whilst the instant at which the time record is made a mark must be made on the edge of the diagram which is being drawn by the seismograph. Such a seismograph has been constructed and is now erected in Japan. It is illustrated in the accompanying diagram. The Gray and Milne Seismograph.—In this apparatus two mutually rectangular components of the horizontal motion of the earth are recorded on a sheet of smoked paper wound round a drum, d, kept continuously in motion by clockwork, w, by means of two conical pendulum seismographs, c. The vertical motion is recorded on the same sheet of paper by means of a compensated-spring seismograph, s l m b. The time of occurrence of an earthquake is determined by causing the circuit of two electro-magnets to be closed by the shaking. One of these magnets relieves a mechanism, forming part of a time- keeper, which causes the dial of the timepiece to come suddenly forwards on the hands and then move back to its original position. The hands are provided with ink-pads, which mark their positions on the dial, thus indicating the hour, minute, and second when the circuit was closed. The second electro-magnet causes a pointer to make a mark on the paper receiving the record of the motion. This mark indicates the part of the earthquake at which the circuit was closed.
- 47. Fig. 8. The duration of the earthquake is estimated from the length of the record on the smoked paper and the rate of motion of the drum. The nature and period of the different movements are obtained from the curves drawn on the paper.
- 48. Mr. Gray has since greatly modified this apparatus, notably by the introduction of a band of paper sufficiently long to take a record for twenty-four hours without repetition. The record is written in ink by means of fine siphons. In this way the instrument, which is extremely sensitive to change of level, can be made to show not only earthquakes, but the pulsations of long period which have recently occupied so much attention.
- 50. CHAPTER III. EARTHQUAKE MOTION DISCUSSED THEORETICALLY. Ideas of the ancients (the views of Travagini, Hooke, Woodward, Stukeley, Mitchell, Young, Mallet)—Nature of elastic waves and vibrations—Possible causes of disturbance in the Earth’s crust—The time of vibration of an earth particle—Velocity and acceleration of a particle—Propagation of a disturbance as determined by experiments upon the elastic moduli of rocks—The intensity of an earthquake—Area of greatest overturning moment—Earthquake waves— Reflexion, refraction, and interference of waves—Radiation of a disturbance. Ideas of Early Writers.—One of the first accounts of the varieties of motion which may be experienced at the time of an earthquake is to be found in the classification of earthquakes given by Aristotle.[8] It is as follows:— 1. Epiclintæ, or earthquakes which move the ground obliquely. 2. Brastæ, with an upward vertical motion like boiling water. 3. Chasmatiæ, which cause the ground to sink and form hollows. 4. Rhectæ, which raise the ground and make fissures. 5. Ostæ, which overthrow with one thrust. 6. Palmatiæ, which shake from side to side with a sort of tremor. From the sixth group in this classification we see that this early writer did not regard earthquakes as necessarily isolated events, but that some of them consisted of a succession of backward and forward vibratory motions. He also distinguishes between the total duration of an earthquake and the length of, and intervals between, a series of shocks. Aristotle had, in fact, some idea of what modern writers upon ordinary earthquakes would term ‘modality.’ The earliest writer who had the idea that an earthquake was a pulse-like motion propagated through solid ground appears to have been Francisci Travagini, who, in 1679, wrote upon an earthquake
- 51. Welcome to our website – the ideal destination for book lovers and knowledge seekers. With a mission to inspire endlessly, we offer a vast collection of books, ranging from classic literary works to specialized publications, self-development books, and children's literature. Each book is a new journey of discovery, expanding knowledge and enriching the soul of the reade Our website is not just a platform for buying books, but a bridge connecting readers to the timeless values of culture and wisdom. With an elegant, user-friendly interface and an intelligent search system, we are committed to providing a quick and convenient shopping experience. Additionally, our special promotions and home delivery services ensure that you save time and fully enjoy the joy of reading. Let us accompany you on the journey of exploring knowledge and personal growth! ebookfinal.com