The astronomical location of the boundaries of the several States and
Territories, as well as of the United States, is a duty frequently
required of the engineer officer, and such a survey between this
country and Mexico is now in progress. The entire line of the 49th
parallel of latitude from the Lake of the Woods to the Pacific Ocean,
which forms our northern boundary, was located a few years ago by a
joint commission of English and United States engineers, and monuments
were established at short intervals over its entire length.
A careful geodetic and hydrographic survey of the Great Northern
Lakes, including every harbor upon them and the rivers connecting
them, was carried on for many years and was finally completed some ten
years ago. Maps and charts of these surveys are published from time to
time for use of pilots navigating these waters.
Not only are the duties of the military engineer similar in many
respects to those of the civil engineer, but there are many instances
in which the duties of one branch of the profession have been
performed by members of the other branch, quite as efficiently as
though they had been performed by engineers specially educated for the
purpose. During the late civil war there were many illustrations of
this, all showing that an ingenious engineer can readily adapt himself
to circumstances entirely different from those to which he has been
accustomed. A very good example of this occurred in the Red River
expedition of General Banks and Admiral Porter. In that memorable but
disastrous campaign an army accompanied by a fleet of transports and
light draught gunboats, sometimes called "tin clads" because some
parts of them were covered with boiler plate to stop the bullets of
the enemy, ascended the Red River in Louisiana; but the advance having
been checked and a retreat commenced, it was found that the river had
fallen to such a low state that the fleet was caught above the rapids
near Alexandria, and it would in all probability have been a complete
loss had it not been for the timely application of engineering skill
by Lieut. Col. Joseph Bailey, a civil engineer from Wisconsin, who
built a temporary dam across the river below the rapids and floated
out the entire fleet. This dam was over 750 feet long and in
connection with some auxiliary dams raised the water level some 6½
feet. It was built under many difficulties, but by the skill and
ability of the engineer and the co-operation of the troops it was
completed in ten days. Another case was at the siege of Petersburg,
Va., where Lieut. Col. Pleasants, a Pennsylvania coal miner, ran a
gallery from our lines, under the rebel battery, some 500 feet
distant, and blew it entirely out of existence. The mine contained
four tons of powder and produced a crater 200 feet by 50 feet and 25
feet deep, and was completed in one month. The sequel to this was to
be an attack on the enemy's line through the gap made by the
explosion, and such an attack properly followed up would doubtless
have had a marked effect in shortening the duration of the war, but
this attack was so badly managed that it utterly failed and caused a
severe loss to our own army. The mine itself, however, was a great
success and produced a decided moral effect on both sides which lasted
until the end of the war.
It may be out of place to digress a moment to illustrate the moral
effect of such a convulsion. Several weeks after this great mine
explosion, the 18th Army Corps, to which I then belonged, was holding
a line of works recently captured from the rebels, about six miles
from Richmond, when one night the colonel commanding Fort Harrison, a
large field work forming a part of this line, came down to
headquarters and reported that some old Pennsylvania coal miners in
his command had heard mining going on under the fort. As the nearest
part of the enemy's line was some 400 yards from the fort, I was quite
certain that they could not have run a gallery that distance in the
time that had elapsed since we occupied the work, but there was of
course the possibility that the mine had been partly built beforehand
so as to be ready in just such a case as had arisen, viz., the capture
of the fort by our troops. I therefore went with the colonel up to the
fort to listen for the mining operations, and got the men who claimed
to have heard the subterranean noises, down in the bottom of the ditch
of the fort, which was ten feet deep, and at the angles formed a
fairly good listening gallery, but nothing unusual could be heard. I
therefore made arrangements to sink a line of pits in the bottom of
the ditch, something like ordinary wells; the bottoms of these pits to
be finally connected by a horizontal gallery which would envelop the
fort and enable us to hear the enemy and blow him up, before he could
get under the fort. Although the commanding officer of that fort was
as brave an officer as the war developed, he would not keep his men in
the fort after dark, but withdrew them quietly to the flanks of the
work, where they not only would be safe from an explosion, but would
be ready to fall upon the enemy in case he should blow up the fort and
rush in to capture the line, as our troops had attempted to do at
Petersburg. No explosion took place, however, and after our
countermining work was completed, the garrison became reassured and
remained in the fort at night as well as in day time. A few months
later, when the enemy was driven from his lines, I went through his
works to see whether any mining had been attempted, and found that a
gallery leading toward Fort Harrison had been carried quite a
distance, but was still incomplete, and it is barely possible that the
old miners were right, after all, in thinking that they could hear the
sound of the pick, although the distance was almost too great to make
this theory very probable.
Still another illustration of the way in which civil engineers can
make themselves extremely useful in military operations was the
wonderful system of military railways, or railways operated for
military purposes, that formed complete lines of transportation for
the armies and their enormous quantities of supplies and munitions,
more especially those in the West and Southwest. Construction trains
were organized in the most complete style, and when a piece of track
or a number of bridges were destroyed by the enemy, they would be
rebuilt so rapidly that our trains would hardly seem to be delayed by
it. The trains carried spare rails, ties, and bridges of various
lengths ready to put up, and they also carried the necessary rolling
stock and tools for destroying the roads and bridges of the enemy. So
expert had this construction corps become that the enemy was ready to
believe almost any statement in regard to it. General Sherman tells of
an instance where it was proposed to blow up a tunnel, to check his
"March to the Sea," when one of the men objected, saying it was of no
use, for Sherman had a duplicate tunnel in his train.
Although this is not a sermon, it may not be out of place to point out
a few qualifications common to all engineers, for they all deal more
or less with the same materials and forces and employ similar methods
of investigation and construction. Wood, iron, steel, copper and stone
and their compounds are the materials of the civil, mining, mechanical
and electrical, as well as of the military engineers. They all deal
with the forces of gravitation, cohesion, inertia and chemical
affinity. They all require skill, intelligence, industry, confidence,
accuracy, thoroughness, ingenuity and, beyond all, sound judgment.
Wanting in any one of these qualifications, an engineer is more or
less disqualified for important work. It is said that a distinguished
engineer was always afraid to cross his own bridges, although built in
the most thorough and approved manner. He was deficient in confidence.
Another engineer distinguished for his mathematical attainments built
a bridge which promptly collapsed at the first opportunity. On
overhauling his computations he ejaculated somewhat forcibly, "That
confounded minus sign! It should have been plus." He was deficient in
sound judgment, or what is sometimes called "horse sense."
Another and more common defect in young engineers is a want of
thoroughness. It is generally best to go to the bottom of a question
at first and keep at it until it is thoroughly and fully completed.
Confucius says, "If thou hast aught to do, first consider, second act,
third let the soul resume her tranquillity." Those who begin a great
many things and never fully complete them lose a great deal of
valuable time, but do very little valuable work. The way to avoid this
difficulty is to be cautious about beginning things, but when once
started don't leave it until you are satisfied to leave it for good.
There is an Arabian saying, "Never undertake _all_ you can do, for he
who undertakes _all_ he can do will frequently undertake _more_ than
he can do."
Another common error is extravagance. On the plea that "the best is
always the cheapest," and to be sure of a large factor of safety, or
as the late Mr. Holley called it a "factor of ignorance," without much
trouble to themselves, some engineers use more or better materials
than the work requires, and thus greatly increase the cost without any
corresponding advantage. Almost any engineer can do almost anything in
the way of engineering if not limited by the cost, but the man who
knows just what materials to use and how to use them so that they will
answer the purpose as to strength and durability can save his own
salary to his employer many times over by simply omitting unnecessary
expense.
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