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Database Systems: Instructor’s Guide - Part
III
7
Database Systems A Practical Approach to
Design Implementation and Management 6th
Edition Connolly Solutions Manual
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connolly-solutions-manual/
Chapter 2 Database Environment
Review Questions
2.1 Discuss the concept of data independence and explain its importance in a database environment.
See Section
2.1.5
2.2 To address the issue of data independence, the ANSI-SPARC three-level architecture
was proposed. Compare and contrast the three levels of this model.
See Section
2.1
2.3 What is a data model? Discuss the main types of data models.
An integrated collection of concepts for describing and manipulating data, relationships
between data, and constraints on the data in an organization. See Section 2.3.
Object-based data models such as the Entity-Relationship model (see Section 2.3.1).
Record- based data models such as the relational data model, network data model, and
hierarchical data model (see Section 2.3.2). Physical data models describe how data is stored
in the computer (see Section 2.3.3).
2.4 Discuss the function and importance of conceptual modeling.
See Section
2.3.4.
2.5 Describe the types of facility you would expect to be provided in a multi-user DBMS.
Data Storage, Retrieval and Update Authorization Services
A User-Accessible Catalog Support for Data Communication
Transaction Support Integrity Services
Concurrency Control Services Services to Promote Data Independence
Recovery Services Utility Services

III
8
See also Section
2.4
2.6 Of the facilities described in your answer to Question 2.5, which ones do you think would
not be needed in a standalone PC DBMS? Provide justification for your answer.
Concurrency Control Services - only single
user.
Authorization Services - only single user, but may be needed if different individuals are to use
the
DBMS at different
times.
Utility Services - limited in
scope.
Support for Data Communication - only standalone
system.

III
9
2.7 Discuss the function and importance of the system catalog.
See Section 2.4, Service (2) – User-accessible
catalog.
2.8 Discuss the differences between DDL and DML? What operations would you typically
expect to be available in each language?
DDL - A language that allows the DBA or user to describe and name the entities, attributes,
and relationships required for the application, together with any associated integrity
and security constraints.
DML - A language that provides a set of operations to support the basic data
manipulation operations on the data held in the database.
See Section
2.2.2.
2.9 Discuss the differences between procedural DMLs and nonprocedural DMLs?
Procedural DML - A language that allows the user to tell the system what data is needed
and exactly how to retrieve the data.
Nonprocedural DML - A language that allows the user to state what data is needed rather
than how it is to be retrieved.
See Section
2.2.2.
2.10 Name four object-based data models.
• Entity-Relationship (ER)
• Semantic
• Functional
• Object-
oriented. See
Section 2.3.1.
2.11 Name three record-based data models. Discuss the main differences between these
data models.
• relational data model - data and relationships are represented as tables, each of
which has a number of columns with a unique name
• network data model - data is represented as collections of records, and relationships
are

III
1
0
represented by sets. Compared with the relational model, relationships are explicitly
modeled by the sets, which become pointers in the implementation. The records
are organized as generalized graph structures with records appearing as nodes (also
called segments) and sets as edges in the graph

III
1
1
• hierarchical data model - restricted type of network model. Again, data is represented
as collections of records and relationships are represented by sets. However, the
hierarchical model allows a node to have only one parent. A hierarchical model can be
represented as a tree graph, with records appearing as nodes (also called segments) and
sets as edges.
See Section
2.3.2.
2.12 What is a transaction. Give an example of a transaction.
A transaction is a series of actions, carried out by a single user or application program,
which accesses or changes the contents of the database.
See Section
2.4.
2.13 What is concurrency control and why does a DBMS need a concurrency control facility?
A mechanism to ensure that the database is updated correctly when multiple users
are updating the database concurrently.
This avoids inconsistencies from arising when two or more transactions are executing and
at least one is updating the database.
See Section
2.4.
2.14 Define the term "database integrity". How does database integrity differ from database
security?
“Database integrity” refers to the correctness and consistency of stored data: it can
be considered as another type of database protection. Although integrity is related to
security, it has wider implications: integrity is concerned with the quality of data itself.
Integrity is usually expressed in terms of constraints, which are consistency rules that the
database is not permitted to violate.
See Section 2.4.
Exercises
2.15 Analyze the DBMSs that you are currently using. Determine each system’s compliance with
the functions that we would expect to be provided by a DBMS. What type of language does
each system provide? What type of architecture does each DBMS use? Check the
accessibility and extensibility of the system catalog. Is it possible to export the system catalog
to another system?

III
1
2
To do this you will need to obtain appropriate information about each system. There should
be manuals available or possibly someone in charge of each system who could supply the
necessary information.

III
10
2.16 Write a program that stores names and telephone numbers in a database. Write another
program that stores names and addresses in a database. Modify the programs to use external,
conceptual, and internal schemas. What are the advantages and disadvantages of this
modification?
The programs can be written in any suitable language and should be well structured
and appropriately commented. Two distinct files result. The structures can be combined
into one containing name, address, and telNo, which can be the representation of both the
internal and conceptual schemas. The conceptual schema should be created separately with
a routine to map the conceptual to the internal schema. The two external schemas also must
be created separately with routines to map the data between the external and the conceptual
schema. The two programs should then use the appropriate external schema and routines.
2.17 Write a program that stores names and dates of birth in a database. Extend the program so
that it stores the format of the data in the database; in other words, create a system catalog.
Provide an interface that makes this system catalog accessible to external users.
Again, the program can be written in any suitable language. It should then be modified to add
the data format to the original file. This should not be difficult, if the original program
is well structured. The interface for other users operates on the data dictionary and is separate
from the original program. A menu-based interface is adequate.

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set of photographs which had been taken to show the progress of
this mighty work.
“We have never given out any of the photographs before,” he
said, “and only portions of the report; but since you came to Italy on
purpose to learn about the mountain whose top was blown off, the
Comando Supremo may be moved to make a special dispensation in
your favour.”
Exclusive permission to make use of both report and
photographs was granted me in due time, and since the former
makes clear both the “why” and the “how” of the unprecedented
Castelletto operation, it will perhaps be best to summarise it first as
a sort of drab background for the more vivid and intimate personal
details which a lucky turn of the fitful weather vane made it possible
for me to obtain later.
The first part of the report, by the Colonel commanding the
Alpini Group, makes plain why the mining of the Castelletto became
a sine quâ non to further progress in this important sector.
“In the month of October, 1915,” he writes, “I was charged with
the carrying out of an attack with two battalions of Alpini against the
positions of Castelletto and Forcella Bois. This was the fourth time, if
I am not mistaken, that an attempt on these positions had been
made. In spite of the fact that the artillery preparation of the
opening day had been excellently performed I discovered, on the
evening of October 17, when I moved with my troops to the attack,
that its work had been absolutely of no avail.
“Having received orders at midnight to proceed to Vervei, where
the two battalions above mentioned were to take part in another
operation, I was forced to abandon the attack. I am convinced,
however, that I would not have succeeded in capturing the
Castelletto position.”
“As known,” the report continues, “the Castelletto is a sort of a
spur of the Tofana (about 12,000 feet high), with a balcony shaped
like a horse-shoe, and with a periphery consisting of numerous
jagged peaks. In the rear of the balcony, and within this rocky spur,
the enemy had excavated numerous caverns in which machine-guns
and light artillery pieces, handled by isolated but able gun-crews,

furnished an invisible and almost impregnable position of defence,
giving extraordinary confidence and encouragement to the small
forces occupying them.
“Costeana Valley was accordingly at the mercy of the enemy’s
offence and actually cut in two. From Vervei on, all movements of
troops had to be carried on only at night and with great difficulty.
The conquest of the Castelletto was rendered necessary not only for
tactical but for moral reasons as well, since our troops came to
regard it as absolutely imperative that such an obstacle should be
overcome. After completing my observations and researches
regarding the Castelletto position, I reached the conclusion that the
only means of dislodging the enemy therefrom was to blow it up.
“On November 19 I formally presented my plan to
Headquarters, and about the middle of December I was authorised
to attempt it. The unusual enterprise was a most difficult one, not
only on account of its magnitude, but also on account of the
particularly unfavourable conditions of the winter season. Having
prepared the necessary material for construction and excavation
work, I began, on January 3, 1916, fortifying the position (entirely
unprotected at the time) from which we would have to work, and
completing the construction of the necessary buildings.
“Second Lieutenant Malvezzi, in his report on the subject,
describes concisely and modestly the development of the work. The
accomplishment of the enterprise, considered by many as chimerical,
is due not only to the technical ability of Lt. Malvezzi, and Lt. Tissi,
his assistant, but to their special military qualifications as well; also
to the courage and goodwill of the Alpini who, in a very short time,
became a personnel of able miners and clever mechanics.
“The vicissitudes during more than six months’ work, at a
distance of only a few metres from the enemy, and under an
incessant artillery fire and shelling by bombardas, could well form
the subject for a book devoted to the study of character. Although
fully aware of the attendant dangers, including those of falling rocks
due to the counter-mining of the enemy, the Alpini of the Castelletto,
during the period of more than six months, gave proofs of brilliant

valour and unflinching perseverance. They were calm at all times,
and moved only by the spirit of duty.
“In transmitting to Your Excellency the enclosed copy of the
report compiled exclusively by Lt. Malvezzi (Lt. Tissi is at present
lying wounded in the hospital), I desire to recommend to you these
two officers (both as excellent engineers and brave soldiers), as well
as the Alpini who were co-operating with them. Without any
exaggeration, I consider their achievement as absolutely marvellous,
both on account of the great technical difficulties surmounted and
the military results obtained. The Austrian officers taken prisoner
unanimously confirm the fact that only by springing a mine could the
Italians have taken this position so important to the enemy.”
Lt. Malvezzi’s appended report launched at once into the “how”
of the titanic task which was set for him.
“On January 3, 1916,” he writes, “work was begun on the
approach to Castelletto, on the Tofana di Roches slope, levelling the
soil and enabling the construction of lodging quarters for officers and
troops. This work required the cutting of 660 cubic metres of rock.
Next the construction of quarters, and the concealing them was
quickly accomplished. Finally, there was garrisoned at this post the
Castelletto Detachment, commonly called the ‘T.K.,’ consisting of the
necessary personnel for labour and the defence of the position.
“Our first work was to examine and disclose the enemy lines of
communication about the Castelletto and Tofana sides, and to gain
full knowledge of their position in detail. In order to accomplish this,
observation points were established which allowed us to carry out
such investigation and to make topographical sketches of the zone.
Being as we were always in the proximity of the enemy, this was a
long and fatiguing work. After a month, however, we succeeded in
constructing a series of positions at short distances from those of
the enemy (from 50 to 150 metres). These were provided with
cables and rope ladders to enable us the more rapidly and easily to
study (from all possible points of vantage) the enemy’s positions and
the development of his works.

“The topographic work was begun by taking as a plan metric
base measurement 116 metres of ground on a four-triangle table,
which method enabled making all other drawings based on it. By
basing our findings on this table, we were able to draw up a series
of points of the enemy’s positions. Using the method of successive
intersections, we thus obtained all points of interest to us, as
regards direction, distance and height.
“In addition to this work, executed with the greatest care and
accuracy, we made two independent drawings of the enemy’s
positions by simpler but less exact methods. The first was made with
a topographic compass and Abney level; the other with a Monticole
field-square. By these means we obtained excellent checks on the
base system, and so grounded our work entirely on the
trigonometric table and on the drawings by intersections.
“From the middle of February to the end of March the tools
used for piercing consisted only of mallets and chisels. Our progress
was necessarily slow, yet it was sufficient in this time to give us,
besides 14 metres of tunnel, room for installing the perforating
machinery. At the end of March, notwithstanding heavy snowstorms,
the machinery—some pieces of it weighed as much as 500 and 600
kilos—for beginning work was installed. This was all brought up by
hand, and without incident.
“The mechanical work was begun on April 2. We utilised two
plant as follows:
“(1) A complete group of benzo-compressors, consisting of a
30-40 horse-power kerosene motor adjusted to a Sullivan
compressor by means of a belt. This machinery was installed, on a
solid base of cement, at the beginning of the tunnel, in a 5 × 8
metre space dug out in the side of the mountain for that purpose.
“(2) An Ingersoll compressor mounted on a four-wheel truck.
“Both machines were of American manufacture, and gave
complete satisfaction at all times. Each compressed the air to a
density of about seven atmospheres, injecting it into an air-chamber,
whence, by means of a rigid tube, ending in one of flexible rubber, it
was conveyed to the respective drills.

“Four squads worked at a time, each one consisting of a
foreman and from 25 to 30 miners. Each squad worked six hours
without interruption. This shift, apparently light, was found, on the
contrary, to be very heavy, owing principally to the development of
nitric gases which poisoned the air, and to the dust caused by the
drills.
“At first the only explosive used was military gelatine; later,
dynamite-gelatine. The system of over-charging the holes was
always adopted, in order to reduce the débris to minute particles,
easier to be transported and unloaded. The work was carried on in
sections, varying from 1·80 by 1·80 metres to 2 by 2. The flat
stretches of the tunnel were laid with Decauville rails. All material
was carried out in cars and dumped into a hopper discharging into a
large pipe. (The dump was accumulated at a point beyond the
observation of the Austrians.) The average rate of progress was 5·10
metres per day.”
It may be well to explain here that it was not possible to begin
tunnelling on the same level at which the mine was to be exploded,
but considerably more than 150 feet below that level. The tunnel,
had, therefore, to be driven on a steep gradient. Another point
which the report does not make clear should be borne in mind, viz.,
that the tunnel divided in the heart of the Castelletto, the main bore
being driven on to where the mine was to be exploded, while a
smaller branch—referred to below as the “Loop-holed Tunnel”—was
run up to a point where favourable exit could be obtained for
charging into and occupying the crater of the exploded mine. In all
507 metres of tunnel had to be driven, involving the excavation of
2,200 cubic metres of rock. The details of this work are given in the
report as follows:
(A) Chamber for Sullivan Compressor: Dimensions: 5 × 8
metres; average height 2·20 metres.
(B) First part of gallery to second dump of material. Length 72
metres; inclination 38·70 per cent.; elevation gained 25·90 metres.
(C) Second dump of material, established in order to free space
for further work and reduce the length of transportation.

(D) Ingersoll Group chamber. Dimensions: 4 × 6·50 metres;
average height 2 metres.
(E) Cut from the gallery of the second dump of material to the
beginning of the ascent to the mining chamber. Length 136 metres;
inclination 4·70 per cent.; elevation gained 6·40 metres.
(F) Ascent to mining chamber. Length 22 metres; inclination
36·30 per cent.; elevation gained 10·75 metres. (This ascent, in
order to facilitate tamping, was worked by dividing it into three
sections of 1 × 1·60 metres, at nearly right angles.)
(G) Mining chamber. Dimensions: 5 × 5·50 metres; average
height 2·30 metres.
(H) Loop-holed tunnel. Length 162 metres; inclination 60 per
cent.; elevation gained 83·50 metres in this tunnel itself, or a total of
168·50 from the second dump. This tunnel (the one through which
the men were to pass for the attack after the explosion of the mine)
had to be strictly confined to the rocky stratum between the Tofana
and the Castelletto; its planimetry appears (see map), therefore,
rather uneven due to the constant elevation of the rock.
(I) Line of communication—partly in a natural cavern—
measuring about 250 metres in length and giving access from the
lodging quarters to the works.
(J) Tunnel dug out to the extreme south end of the Castelletto,
30 metres long, with two portholes (each 4 metres wide) for two
Depfort guns, with closed cavern for the guns and ammunition.
“It was originally intended to divide the explosive charge
between two chambers, each having a mining line of resistance of
20 metres, with a 16-ton explosive charge of 92 per cent. gelatine.
However, owing to the countermining work carried on by the enemy
—we were only a few metres from one of his positions during the
charging of the mine chamber—we were obliged to confine the
entire charge to a single chamber.
“The enemy meanwhile, with a view to avoiding the effects of
our mine beneath the peaks of the Castelletto, had transferred most
of his shelters to the side of the Tofana and the Selletta. This
necessitated a considerable alteration in the location of the mine as

originally planned, in order that it should act against the enemy
shelters on both the Castelletto and Tofana flanks.
Plan of the Castelletto Mining Operation.
The worm-like tunnel on the left had to be driven in
this way in order to avoid fissures in the rock which
would have revealed what was going on. It was this
tunnel through which the Alpini were to pass to
occupy the crater after the explosion of the mine, but
this plan was defeated through the presence of gas
from detonated Austrian asphyxiating bombs.
“The charge was computed on a basis of minimum resistance of
20 metres, taking into consideration the nature of the rock (which
was fissured) and the existence of numerous splits and caverns. The

co-efficient of overcharge was, therefore, rather high. In order to
obtain the maximum effect under these conditions, only 92 per cent.
explosive nitro-glycerine was used. The total charge was 35 tons.
“The method of priming adopted was suggested by Lieut.-Col.
Tatoli, of the Engineers Corps. This consisted of five priming groups,
each of three friction tubes. One of the groups ran along the central
axis of the chamber, while the other four, parallel with the first, were
disposed symmetrically facing the four corners of the chamber. Each
tube (1-1/4 inches inside diameter by 4·50 metres in length) was
alternately charged with gelatine and gun-cotton and pierced by
picric acid detonating fuse, ending in a gun-cotton cartridge with
electric percussion cap. In the very centre of the charge there were
inserted two cases of gun-cotton, with electric percussion cap and
detonating fuse, with a view to securing a second springing of the
mine to follow the first.
“We thus had in all seventeen electric circuits divided into three
groups, each formed by the circuits of five tubes, connected with the
five groups of friction tubes. Two of these electric groups were
composed of six circuits each, by adding the two circuits of the
above-mentioned cases containing the gun-cotton. Each of these
electric groups ended with a Cantone exploder, placed at about 4·50
metres distance from the mine-chamber.
“The tamping was effected with cement and with sandbags,
with heavy wooden beams between the latter. It was made more
effective by dividing into sections at right angles to each other. The
theoretical length of the tamping was 25 metres.
“The charging of the mine chamber began July 3, 1916, at 5
p.m., and was completed at 3 p.m. of July 9 this work including
tamping, priming, and laying of electric circuits. The final
connections between the latter and the exploders, by means of wires
suspended in the air, were made on July 10. The mine was sprung
on July 11 at 3.30 p.m., and responded fully to our calculations and
expectations.
“(Signed) L. Malvezzi,
2nd Lieut. 7th Regiment Alpini.”

A week of unspeakable weather went by—an interval the days
of which I spent among the “Cave-men” of the Carso, and the nights
of which were largely devoted to puzzling through the mysteries of
the Castelletto report with the aid of my Italian dictionary—and then
the unexpected miracle happened. Rain and snow ceased, the sky
cleared, and a spell of sparkling days succeeded the interminable
months of storm and lowering clouds. From the high Alps came word
that the grip of the frost had paralysed the avalanches for the
moment, and that rapid progress was being made in opening up the
roads for traffic.
“Now is your chance to see the Castelletto,” they told me at
headquarters. “If you start at once you ought to be able to get
through without much trouble; and, if the weather holds good, you
may even be able to get back without long delay, though on that
score you’ll have to take your chances. Doubtless they will be able to
get you out in some way whatever happens.”
And so it chanced that on a diamond-bright morning in early
January I found myself, after a couple of days of strenuous
motoring, speeding in a military car past the old custom-house and
up into the heart of that most weirdly grand of all Alpine regions, the
Dolomites. Already we were well over into what had once been
Austrian territory, and the splintered pinnacles which notched the
skyline ahead of us were, as my escorting officer explained, held in
part by both the Italians and the enemy. As we coasted down into
Cortina di Ampezzo—which in its swarming tourist hotels of motley
design rivals St. Moritz or Chamonix—Capt. P—— pointed to where a
clean-lined wall of snow-capped yellow rock reared itself against the
deep purple of the western sky.
“That high mountain ridge is the Tofana massif,” he said, “and
that partly isolated mass of lighter-coloured rock (crowned with
towers like a mediæval stronghold) at its further end is what is left
of the famous Castelletto. It is twenty kilometres or more away, but
you can see even from here how it dominated the valley and road,
the latter the much-pictured Dolomite road, which is also a route of
great military importance.

“Now look at the end of the Castelletto toward the wall of the
Tofana. Do you see where it seems to have been sliced off smoothly
at an angle of about forty-five degrees? Well, that is the part they
blew off last July. Up to then that end, like the other, was crowned
with a lofty spire. That spire, the base from which it sprung, the
Austrian barracks and munition depôts, together with the men
stationed there—all were blown up and destroyed in the explosion.
“Take a good look at it while you have a chance, for the skyline
view is better from a distance than from close at hand, where we
shall go this afternoon if the way is open. To see the effect of the
explosion at its best,” he added, “one should look at it from the
Austrian lines, as it was the blowing out of the other side of the
mountain which undermined and let down the top. If you come back
here in the spring doubtless we will be in occupation of a number of
interesting observation points over there.”
Viewed even from a distance of a dozen miles or more the
alteration wrought in the skyline by the explosion was not difficult to
imagine. It was, indeed, literally true—what I had never been fully
able to make myself believe until that moment—that a mountain
peak had been blown off—hundreds of feet of it, and thousands of
tons. My eyes remained focussed in awed fascination on the
unnaturally even profile of the wound until our snorting car skidded
round a bend of the frozen road and the thick-growing pine forest
shut it from sight.
It was not until, after ten miles of precarious climbing and
clawing up the ice-paved, snow-walled road, our car brought up in
the midst of a neat little group of Alpine buildings nestling in the
protection of the last of the timber, that Capt. P—— revealed the
surprise that had been prepared for me.
“Our host here,” he said, “will be Colonel X——, who conceived
and directed the Castelletto project, and at dinner to-night you will
meet, and can talk as long as you like, with Lieutenant Malvezzi,
who did the work. He is still quartered here, and will be glad to tell
you all that he can about Alpine military engineering. We have
already sent him word that you came to Italy expressly to see him.”

After a hasty lunch Capt. P—— and I, accompanied by an officer
of Alpini from the camp, started for the Castelletto. Our powerful
military car, which, in spite of the fact that it had non-skid tyres, had
been giving a good deal of trouble on the ice, was left behind, and a
smaller but heavily-engined machine, with sharp spikes clamped
over the rims to grip the glassy surface of the road, was taken for
the few miles of the latter which were still open. Abandoning this in
a snow-bank at a little advanced camp well up under the towering
wall of the Tofana, we took our alpenstocks and started on the
2,000-foot climb up to the base of the Castelletto.
The hard-packed snow on the thirty to forty degree slope must
have averaged from ten to twenty feet deep all the way, while, for a
half-mile or so midway, it was humped up in crumpled fold where, a
fortnight before, one of the largest and most terrible slides ever
known in the Alps had plunged down on its sinister mission to the
bottom of the valley. The full story of that avalanche will hardly be
told until after the war.
Slightly softened by the brilliant sun, the snow gave good
footing; but even so it was a stiff pull to the little ice and rock-begirt
barracks at the base of the cliff, and I gained some idea of the
titanic labour involved in getting guns, munitions, machinery, food,
and thirty-five tons of high explosive up there, all by hand, in every
sort of weather, and much of it (to avoid enemy observation and
fire) at night.
Midwinter was not, of course, the time to see anything of the
real effects of the great explosion, for the huge crater torn by the
latter was drifted full of snow, and snow was also responsible for the
complete obliteration of the countless thousands of tons of débris
that had been precipitated down the mountain side. A dizzy climb up
the ladder-like stairway, and a crawling clamber through a hundred
yards of the winding tunnel from the rock chambers which had
housed the compressors, revealed about all that was visible at the
time of the preparations and consequences of the mighty work; but
a peep from the observation port of a certain cunningly concealed
gun-cavern discovered a panorama which gave illuminative point to
the concluding words of the artillery officer who, pointing with the

shod handle of an ice-pick, explained the situation to me from that
vantage.
“So you see,” he had said, “that the Castelletto in the enemy’s
hands was a stone wall which effectually barred our further
progress; while in our hands it becomes a lever which—whenever
we really need to take them—will pry open for us positions of vital
importance. We simply had to have it; and so we took it in the one
way it could be taken.
“Save for his Alpini uniform Lieutenant Malvezzi, when I met
him at dinner that evening, might well have passed for the typical
musician of drama or romance. His skin and hair and eyes were
dark, and his long nervous fingers flitted over the paper on which he
sketched various phases of the Castelletto work very much as those
of a pianist flit above his ivory keys. The dreamy, far-away look in his
eyes was also suggestive of the musician, but that I had long come
to recognise as equally characteristic of all great engineers, the men
whose tangible achievements are only the fruition of days and nights
of dreaming.
“Where shall I begin the story?” he had asked as the diners in
the regimental mess began to resolve into little knots of threes and
fours over coffee and cigars; and I had suggested that he take it up
where his report left off. “That stopped just as things began to
happen,” I said. “Now tell what did happen.”
The Tenente laughed a laugh suggestive of rueful reminiscence,
and a smile ran round among those of the officers who had heard
and understood my words. “So far as I am concerned,” he replied,
“that covers about five minutes of activity—five minutes for which
we had been preparing for six months. You understand that we had
constructed a branch tunnel through which our men were to rush
and occupy the crater as soon after the explosion as possible.
“Ecco. The men were all massed ready on and under the
terrace, and nothing remained but the making of the connection
firing the mine. I took one long look around and then threw over the
electric switch closing the circuit. Every one seemed to be holding

his breath as he waited. One, two, three seconds passed in a silence
so intense that I heard the sharp ‘ping’ of the water dripping from
the roof of the chamber and striking the pool it had formed below.
“Then, before any other sound was audible, the whole mountain
gave a quick convulsive jerk, strong enough to throw some of the
men off their feet. A heavy grinding rumble in the earth came with a
shivering that followed the jerk, but the real roar of the explosion
(from the outside) was not audible for a second or two later. Only
those watching from a distance of several kilometres saw the right-
hand pinnacle of the Castelletto give a sudden heave, and then sink
out of sight in a cloud of dust and smoke.
“In addition to the honour of firing the mine that of leading my
men into the crater had also been reserved for me, and as soon as I
heard the roar of the explosion I gave the order for them to follow
me up into the tunnel. Well——” he paused and ran his laughing
eyes around the grinning circle of his fellow officers, “that is about
as far as my evidence is good for anything. As I went clambering up
the slippery steps of the tunnel an almost solid wall of choking
fumes struck me in the face, and I—and all of my men except those
near or outside of the portal—dropped coughing in my tracks.”
“Had the mine blown back through the tamping?” I asked.
“Not exactly,” he replied, his rueful smile becoming almost
sheepish, as of one who had allowed himself to become the victim of
a prank. “The Austrians had a big store of asphyxiating bombs on
hand to use against us, and these, exploded by our mine, vented
their spite on friend and foe alike. We were not able to occupy the
crater for twenty-four hours.
“I am glad to say that I spent what would otherwise have been
an intolerably anxious interval unconscious in the hospital. By the
time I had been revived a friendly breeze had thinned the gas
sufficiently to allow our Alpini to move into the crater and reap—in
spite of the delay—every advantage we had at any time counted
upon from the operation. Our most cherished capture was the
‘perforator’—practically intact—with which the Austrians were driving
an almost completed counter-mine directly under us.”

“The nervous tension must have been rather strong toward the
end, wasn’t it?” I asked; “especially when you knew the enemy had
at last got your work definitely located and was rushing his counter-
mine?”
The smile of whimsical ruefulness died out of the dark sensitive
face, leaving behind it lines I had not noticed before—lines that only
come on young faces after weeks or months of incessant anxiety.
The backward cast shadows of a time of terrible memory were
lurking behind his eyes as he replied:
“For seven days and nights before the mine was sprung neither
I nor the officers working with me slept or even rested from work.”
That was all he said; but I saw the eyes—brimming with ready
sympathy—of his fellow officers turn to where he sat, and knew the
time for light questionings was past. Not until that moment did a full
appreciation of the travail involved in the blowing up of the
Castelletto sink home to me, and I nodded fervent assent to the
words of the English-educated Captain of Alpini next me when he
observed that “Malvezzi’s little ‘Order of Savoie’ was jolly well
earned, eh?”

WONDERS OF THE TELEFERICA
“Jolly good work, I call that, for a ‘basket on a string,’” was the
way a visiting British officer characterised an exploit of the Italians in
the course of which—in lieu of any other way of doing it—they had
shot the end of a cable from a gun across a flooded river and thus
made it possible to rig up a teleferica for rushing over some badly-
needed reinforcements.
The name is not a high-sounding one, but I do not know of any
other which so well describes the wonderful contrivance which
played so important a part in enabling the Italians to hold
successfully their three hundred miles and more of high Alpine front
during the first two years they were in the war. And in this
connection it should be borne well in mind that the Austrians never
were able to break through upon the Alpine front, where—until the
débâcle upon the Upper Isonzo—the Italians, peak by peak, valley
by valley, were slowly but surely pushing the enemy backward all
along the line. Nor should it be forgotten that up to the very last the
Alpini had their traditional foe mastered along all that hundred and
fifty miles of sky-line positions—from the Carnic Alps, through the
Dolomites to the Trentino—which ultimately had to be abandoned
only because their rear was threatened by the Austro-German
advance along the Friulian plain from the Isonzo. The loss of this line
under these conditions, therefore, detracts no whit from the
magnificent military skill and heroism by which they were won and
held.
The Italians’ conduct of their Alpine campaign must remain a
supreme classic of mountain warfare—something which has never
been approached in the past and may never be equalled in the
future. According to the most approved pre-war strategy, the proper
way to defend mountain lines was by implanting guns on the heights
commanding the main passes and thus rendering it impossible for an

enemy to traverse them. The fact that these commanding positions
were in turn dominated by still higher ones, and these latter by
others, until the loftiest summits of the Alps were reached, was
responsible for the struggle for the “sky-line” positions which the
Austro-Italian war quickly resolved itself into.
This kind of war would have been a sheer impossibility two
decades ago, from the simple fact that no practicable means of
transport existed capable of carrying men, munitions, guns and food
up to continuous lines of positions from ten thousand to thirteen
thousand feet above sea-level. The one thing that made the feat
possible was the development of the aerial tramway, or the
teleferica, as the Italians call it, which gave transport facilities to
points where the foot of man had scarcely trod before. Regular
communication with the highest mountain-top positions would have
been absolutely out of the question without this ingenious device.
As I have said, the “basket-on-a-string” description fits the
teleferica exactly, for the principle is precisely similar to that of the
contrivance by which packages are shunted around in the large
stores and factories. The only points which differentiate it in the
least from the overhead ore-tramways is the fact that—in its latest
and highest development—it is lighter and more dependable. For the
ore-tramway—always built in a more or less protected position—had
only the steady grind of the day’s work to withstand; the teleferica
has not only the daily wear and tear racking it to pieces, but is also
in more or less perennial peril of destruction by flood, wind, and
avalanches, to say nothing of the fire of the enemy’s artillery or of
bombs from his aeroplanes. That the Italians have evolved a
contrivance more or less proof against the ravages of these
destructive agents is, perhaps, the best evidence of their genius for
military engineering. Nothing more perfect in its way than the
teleferica has been produced by any of the belligerents.
Theoretically, a teleferica can be of any length, though I think
the longest on the Italian front is one of three or four miles, which
makes a good part of the eight-thousand-foot climb up to the
summit of the Pasubio, in the Trentino, and which—at the time of
writing—is still in Italian hands. The cable may run on a level—as

when it spans some great gorge between two mountain peaks—or it
may be strung up to any incline not too great to make precarious
the grip of the grooved overhead wheels of the basket. I was not
able to learn what this limit is, but I have never seen a cable run at
an angle of over forty-five degrees. Wherever a cable does not form
a single great span it has to be supported at varying intervals by
running over steel towers to prevent its sagging too near the earth.
A teleferica has never more than its two terminal stations. If the
topography of a mountain is such that a continuous cable cannot be
run the whole distance that it is desired to bridge by teleferica, two
—or even three or four—separate installations are built. This is well
illustrated in the ascent of the Adamello, the highest position on the
Austro-Italian front. One goes to the lower station of the first
teleferica by motor, if the road is not blocked by slides. At the upper
station of this two-mile-long cableway a tramcar pulled by a mule is
taken for the journey over three or four miles of practically level
narrow-gauge railway. Leaving this, a hundred-yard walk brings one
to another teleferica, in the basket of which he is carried to its upper
station, on the brow of a great cliff towering a sheer three thousand
feet above the valley below. Three hundred yards farther up another
teleferica begins, which lands him by the side of the frozen lake at
Rifugio Garibaldi. Three more telefericas—with breaks between each
—and a dog-sled journey figure in the remainder of the climb to the
glacier and summit of the Adamello.
The engine of a teleferica—its power varies according to the
weight and capacity of its basket and the height and length of the
lift—is always installed at the upper station. The usual provision is
for two baskets, one coming up while the other goes down. As with
the ore-tramways, however, an installation can be made—if sufficient
power is available—to carry two or three or even a greater number
of baskets. As this puts a great strain on the cableway the Italians
have only resorted to it at a few points where the pressure on the
transport is very heavy.
The two greatest enemies of the teleferica are the avalanche
and the wind—the latter because it may blow the baskets off the
cable, and the former because it may carry the whole thing away. As

the tracks of snow-slides—the points at which they are most likely to
occur—are fairly well defined, it is usually possible to make a wide
span across the danger-zone with the cable and thus minimise the
chance of disaster on this score. It is only when the dread valanga—
as occasionally happens—is launched at some unexpected point that
damage may be done to an aerial tramway. A great slide—perhaps
the worst which has occurred on the Italian side of the lines during
the war—which came down, a mile wide, from the summit of the
Tofana massif to the Dolomite road in the valley five miles below,
carried away a block of barracks and a battery of mountain guns, in
addition to burying a considerable length of teleferica a hundred feet
deep in snow and débris. Visiting this slide in December, 1916, a few
days after it happened, I saw—at a point where a cut had been run
in an endeavour to save some of the several hundred Alpini who had
been buried—the twisted tower of the teleferica, inextricably mixed
up with the body of a mule and a gun-carriage and overlaid with a
solid stratum of forest trees, two miles below the point at which it
had formerly stood.
Though the number of disasters of this kind from avalanches
may be counted upon one’s fingers, trouble from high wind is always
an imminent possibility. In the early days of the teleferica accidents
traceable to the blowing off of the baskets were fairly common; in
fact, it was feared for a time that the difficulty from this source
might be so great as materially to limit the usefulness of the
cableway system. The use of more deeply-grooved wheels, however,
did away with this trouble almost entirely, so that now the only
menace from the wind is when it comes from “abeam” and blows
hard enough to swing the baskets into collision when passing each
other in mid-air.
Though I have had many a teleferica journey that was distinctly
thrilling—what ride through the air on a swaying wire, with a torrent
or an avalanche below, and perhaps shells hurtling through the
clouds above, would not be thrilling? —I have never figured in
anything approaching an accident, and only once in an experience
which might even be described as “ticklish.” This latter occurred
through my insistence on making an ascent in a teleferica on a day

when there was too much wind to allow it to operate in safety. It
was on the Adamello in the course of an ascent which I
endeavoured to make toward the end of last July.
There was a sinister turban of black clouds wrapped around the
summit of the great peak, and before we were half-way up what had
only been a cold rain in the lower valley was turning into driving
sleet and snow. We ascended by the first teleferica—a double one—
without difficulty, but the ominous swaying of the cables warned us
that the next line, which was more exposed, might be quite another
matter. This latter is the one I have mentioned as running from an
Alpine meadow to the brow of a cliff towering three thousand feet
above it. It was one of the longest—if not the longest—unsupported
cable-spans on the whole Alpine front. It was also the steepest of
which I had had any experience. The fact that it was exposed
throughout its whole length to a strong wind which blew down from
an upper valley was responsible for putting it “out of business”
during bad weather and thus made it the weak link in the attenuated
chain of the Adamello’s communications.
As we had feared, we found this teleferica “closed down” upon
our arrival at the lower station, ample reason for which appeared in
the fifteen or twenty-foot sway given to the parallel lines of cable by
the powerful “side-on” wind gusts which assailed it every few
moments from the direction of the glacier. Fortunately, as the storm
was only coming in fitful squalls as yet and had not settled down to
a steady blow, the tenente in charge thought that it might be
possible to send us up in one of the quieter intervals.
“There’s no danger of the baskets blowing off the cable,” he
said; “it’s only a matter of preventing them striking one another in
passing, of which there is always risk when the wires are swaying
too much.”
As there were three of us and the carrying capacity of the
basket was limited to two hundred kilos, it was necessary to attempt
two trips. As the heaviest of the party, it was decided that I should
ride alone, starting after the two others had gone up. Taking
advantage of a brief quiet spell, my companions were started off.
There was still a good deal of sway to the cables, but a look-out

above kept the engineer advised as to conditions as the baskets
approached each other, and the passage was made without incident.
When my turn came to start, however, the storm had settled down
to a steady gale, and the tenente said he did not dare take the
responsibility of trying to send me through. Ordinarily I should have
been only too ready to acquiesce in his ruling, but as my
companions had just ’phoned word that they were going on by the
next teleferica—a comparatively-protected one—to the Rifugio
Garibaldi, where they would await me before starting on the
following stage of the ascent, I realised at once that my failure to
appear would throw out the whole itinerary and make the trip (which
had to be finished that day or not at all) a complete failure. It was
plainly up to me to get through if there was any way of doing it, and
I accordingly suggested to the young officer that I would gladly sign
a written statement taking the whole responsibility for an accident
on my own shoulders.
“That would not help either you or me very much if things
happened to go wrong,” he said, with a laugh. “If you really must
go, you must; that is all, and we shall simply do our best not to have
any trouble. I shall send one of the linemen along with you to fend
off the other basket in case it swings into yours in passing. There is
a returned American here who ought to be able to do the job and
talk to you in your native tongue at the same time.”
And so it was arranged. I took my place—lying on my back in
the bottom of the basket—as usual, after which Antonio—grinning
delightedly at the prospect of keeping watch and ward over a
“fellow-countryman”—climbed in and knelt between my feet, facing
up the line. Then the “starter” banged three times on the cable to let
the engineer at the top know that all was ready, and presently we
were off along the singing wire.
The ordinary motion of a teleferica is not unlike that of an
aeroplane—though it is not quite so smooth and vastly slower. On
this occasion, however, the swaying of the cable furnished a new
sensation which, while mildly suggestive of the sideslip of an
aeroplane on a steep “bank,” was rather more like the “yawing” of a
“sausage” observation balloon in a heavy wind. The swinging of the

basket itself was also a good deal more violent than I had ever
experienced before, though at no time great enough to make it
difficult to keep one’s place. Both motions were, of course, at their
worst out toward the middle of the span, so that one had an
opportunity to get used to them gradually in the quarter of an hour
which elapsed before that point was reached.
I took the occasion to ask Antonio a question I had been
making a point of putting to every teleferica man I had a chance to
talk with. “Is it really true,” I said, “that no one has been killed since
the war began while riding in a teleferica?”
“A large number of men have been injured,” he replied; “but no
one has been killed outright,” and he went on to tell of a friend of
his who had coasted down a thousand feet because the pulling-cable
jerked loose from the place where it was attached to the basket
when the latter had fouled a “down” basket in passing. He was badly
injured from the jolt he received when the basket brought up short
at the bottom, and it had taken three months in the hospital to put
him right again. He would never walk again without a stick, but he
was so far from being killed that he was the engineer of the very
teleferica on which we were riding. He was a very careful man, said
Antonio, for he fully understood the consequences of letting two
loaded baskets bump in mid-air.
A chill current of spray began to enfold us at this juncture, and
Antonio was just in the midst of an explanation of how it was carried
by the wind from a thousand-foot-high quarter-mile-distant waterfall
coming down behind the curtain of the lowering clouds, when I
suddenly saw him bring the point of his alpenstock over the edge of
the basket and, with his eyes fixed intently ahead, hold himself
poised in an attitude of tense readiness. Just above our heads the
descending basket was swaying to and fro in the strong wind. A
collision seemed imminent when, with a quick lunge of his
alpenstock, Antonio turned it aside, and in that fraction of a second
we passed it unharmed. It had been easy this time, explained
Antonio, because the engineer at the top had slowed down the
baskets to under half-speed at the moment of their passing.

All sorts of freight—from ducks and donkeys to shells and
cannon—have been carried by the teleferica, and one of the best
stories I heard on the Italian front had to do with a pig—the mascot
of a battalion of Alpini holding a lofty position on a Dolomite glacier
—which found its way up there by means of the cable. He was a
sucking-pig, and was sent up alive to be reared for the major’s
Christmas dinner, when the teleferica basket in which he was
travelling got stuck in a drift which had encroached upon one of the
steel towers. Twelve hours elapsed before it was shovelled free, and
the sucking-pig, when it finally reached the top, was frozen as hard
and stiff as one of his cold-storage brothers. It was only after he had
lain in the hot kitchen for several hours that an indignant grunt
revealed the astonishing fact that his armour of fat had kept
smouldering a spark of life. They reared him on a bottle, and at the
time I saw him he was a hulking porker of two hundred pounds or
more, drawing a regular ration of his own. They called him Tedesco
—on account of his face and figure rather than his disposition, they
said—but all the same, I would be willing to wager that, if that brave
battalion of Alpini were able to save anything more than their rifles
and their eagle-plumes in their retreat, he was not allowed to fall
into the hands of his brother Tedeschi from the other side of the
Alps.
But the most noteworthy service of the teleferica is the way in
which it facilitates the handling of the wounded at points where
other ways of transporting them are either too dangerous or too
slow. It was on a sector of the upper Isonzo, where at that time the
Austrians had not yet been pushed across the river. A rather wide
local attack was on at the moment, and to care the more
expeditiously for the wounded a very remarkable little mobile
ambulance—the whole equipment of which could be taken down in
the morning, packed upon seven motor lorries, moved from fifty to a
hundred miles, and be set up and ready for work the same evening
—had been pushed up many miles inside the zone of fire to such
protection as the “lee” of a high ridge afforded.
“We have found,” said the chief surgeon, “that many wounds
hitherto regarded as fatal are only so as a consequence of delay in

operating upon them. This little hospital unit, which is so complete in
equipment that it can do a limited amount of every kind of work that
any base hospital can perform, was designed for the express
purpose of giving earlier attention to wounds of this kind, principally
those of the abdomen. From the first we saved a great number of
men who would otherwise never have survived to reach the base
hospitals; but even so we found we were still losing many as a
consequence of the delay that would often arise in transporting
them over some badly exposed bit of road on which it was not
deemed safe to risk ambulances or stretcher-bearers. Then we
devised a special basket for wounded, to be run on the teleferica (as
you see here), with the result that we are now saving practically
every man that it is humanly possible to save.”
While he was speaking the teleferica, which ended beside the
tent of the operating theatre, began to click, and presently an
oblong box, almost identical in size and shape with a coffin,
appeared against the sky-line of the ridge and began gently gliding
toward us along the sagging cable. “In that box,” continued the
surgeon, “there will be a man whose life depends upon whether or
not his wound can be operated upon within an hour or so of the
time he received it. He was probably started on his way to us within
ten minutes of the time he arrived at the advanced dressing station,
and if he was not left lying out too long the chances are we will pull
him through. All up the other slope of the ridge he came across
ground that is being heavily shelled (as you can see from the smoke
and dust that are rising), but that basket is so small a mark that the
Austrians might fire all day at it without hitting it. One of them
occasionally runs into the ‘pattern’ of a shrapnel burst (with
disastrous results, of course), but the only danger worth bothering
about is of having the teleferica laid up from a shell on the engine-
house or one of the supporting towers. Although the man is
probably unconscious he is coming alone, you see. No other life, and
not even an ambulance, is risked in bringing him here. Except for
the teleferica, he could not have been sent over until after dark, and
the delay would have been fatal. We estimate that from one to three
per cent. of the men wounded on a battlefield which, like this one,

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