popular for a time. As with steel, its beginnings were old, dating
back at least to the year 1857. The first perfected compound plate,
made by Cammel & Co., of England, was tested at Shoeburyness in 1877.
It was composed of 5 inches of iron with a 4-inch face of steel; the
iron being raised to a welding heat and the molten steel poured on its
top. The great heat partially fused the contact face, the two metals
were united, and the combination was assured by immediate rolling.
Compound plates sprang in 1877 from obscurity to popularity; by 1879
iron armor had become obsolete with progressive naval powers, and, in
1880, both compound and steel plates had reached such development that
they were close rivals, the leading competitors being Cammel in England
and Schneider in France. Steel, however, slowly forged ahead during
the next decade; and, at its close, compound armor was practically
out of the race. In steel’s victory, its alloy with nickel, in minute
proportions, has materially aided; the combination imparting hardness
without decreasing the toughness of the plate. This material gave
superior results from the beginning. Its first plate, tested in 1889,
was 9⅓ inches thick; it was pierced by a Holtzer shell, whose body
did not pass wholly through and whose energy was 1.6 times that just
necessary to perforate a wrought-iron plate of the same thickness. To
the increased strength given by nickel there has been added a further
gain through the application of face-hardening processes—such as that
of the American, Harvey—which produce superficial carbonization,
transforming the surface into a high grade of very hard steel,
without the pronounced plane of demarcation between the two qualities
of metal, as in the weld of the compound plate. A 10¼-inch nickel
steel Harveyized plate, tested at the Indian Head Proving Grounds in
1892, showed a strength which previously had never been equaled in
the history of armor, and established beyond question the value of
the face-hardening process, which, by various methods, is applied to
the nickel-steel plating of to-day. The distribution of armor in the
development of battleship construction is shown by the shaded sections
on Plates VI and VII, and its relative thicknesses, on various vessels
during this progress, by Plate VIII.
VII. THE RAM AND THE TORPEDO.
For two thousand years the ram—the razor-edged “beak” of the swift
galley—was the chief naval weapon. With the advent of sail-power and
the employment of gunpowder, it vanished from the seas; but to reappear
when the coming of steam gave again controllable propulsion. In 1859
there was built into the French frigate Magenta a sharp spur,—the
first modern ram. British construction of the modern era, from the
Warrior down, has also recognized this weapon, and it is to-day a
factor, although a minor one, in the design of all vessels of high
speed.
The ram has, however, but a scant record of service in action, while in
accidental collision it has wrought more than once appalling disaster.
The ironclad Merrimac rammed and sank in Hampton Roads, in March,
1862, the United States sailing sloop-of-war Cumberland, which, under
the gallant Morris, went down with guns thundering and ensign flying.
On July 20, 1866, during the action off the island of Lissa, in the
Adriatic, the Austrian flagship Ferdinand Maximilian rammed the Italian
armorclad Re d’ Italia, which, with many of her 800 men, sank with
a swiftness that chilled the blood of those who watched. Like this,
in its sudden tragedy, was the destruction of the British battleship
Victoria by her consort, the Camperdown, off Tripoli, Syria, in the
summer sunlight of a June day in 1893. The ram of the latter vessel cut
a deep and fatal gash in the Victoria, which within ten minutes turned
bottom upward and went down, bow first, bearing with her 321 officers
and men, whose unfaltering discipline gave a heroic splendor to their
end. Despite these occasional instances of its deadly power, the ram
holds a secondary place among naval weapons. To strike a modern vessel
at high speed will require more than the skill of the swordsman.
The torpedo, like the ironclad, was an American invention, whose
neglect by the United States government brought retribution when this
deadly engine of war in 1861–65 destroyed not a few war-vessels flying
our flag. Bushnell of Connecticut during the Revolution appears to have
invented both the submarine boat and the marine torpedo, the latter
being fired by clock-work. Fulton also met success in similar work
during the period extending from 1801 to 1812. All of the elements of
modern torpedo warfare, excepting the use of steam, compressed air, or
electricity as a motive power, had been thus conceived by the early
dawn of this century. The torpedoes of our day are practically of but
two classes: the “mine,” or stationary (either “buoyant” or “ground,”
as its position in the water determines), and the automobile, or
“fish” torpedo. The former type is fired either by closing an electric
circuit in a station on shore, or by the ship herself in contact,
or in electric closure. During the Civil War nearly thirty vessels
were sunk by mines, usually wooden barrels filled with gunpowder and
fired by hauling lines or slow-burning fuses. It was a mine-field
over which Farragut charged at Mobile Bay, when he uttered his famous
oath and went “full speed ahead,” with the cases of the fortunately
impotent torpedoes striking the Hartford’s bottom; it was a mine which,
it is claimed, sunk the Maine; and it was a mine-field which kept
Sampson’s battleships from entering the harbor of Santiago de Cuba.
The stationary torpedo is now charged with gun cotton or other high
explosive.
The origin of the most prominent of the automobile torpedoes is due
to Captain Lupuis of the Austrian navy, and its development from 1864
onward to Whitehead, an Englishman. It is a cigar-shaped submarine
vessel from 14 to 19 inches maximum diameter and from 14 to 19 feet
long, which is blown from a torpedo-tube or gun within the ship by
compressed air or an impulse charge of gunpowder. Twin-screw engines
contained within its hull, and driven by compressed air stored in
a reservoir therein, drive it at about thirty knots speed through
an effective range of 600 yards. In its nose or “war-head” there
is carried a large charge of gun cotton or other high explosive,
which is fired by contact with the enemy’s hull. It is provided with
both horizontal and vertical rudders, the depth of immersion being
regulated by intricate machinery contained in the “balance-chamber.”
The Whitehead has a somewhat formidable rival in the United States in
the torpedo invented by Rear Admiral Howell, U. S. N. The automobile
torpedo has never yet scored in battle against ships in motion. Its
position in the naval warfare of the future is yet unfixed. The one
certainty is, that its blow when struck home is almost surely fatal to
ship and crew. The development of the submarine torpedo-boat, whose
weapon is the Whitehead, has in recent years received much attention
through the labors of the American Holland and others. France, in the
Gustavus Zede, of 260 tons, has a diving boat of this character, for
which much is claimed.
VIII. THE UNITED STATES FLEET.
Until the advent of the ironclad, the ships of the United States were
equal, if not superior, in seaworthiness and fighting qualities to any
in the world. The high standard set by the Constitution and her class
of 1797 was maintained for sixty years; and, especially during the
period from 1840 to 1860, the officers and men of the United States
navy trod the decks of the finest ships afloat. They felt—as their
successors feel—that, ton for ton and gun for gun, they had no foe to
fear. The early steamers of the Powhatan class built in the late 40’s
were a credit to the nation; the five screw frigates of the Merrimac
type (1856–57) aroused the admiration and imitation of foreign experts,
and the five corvettes which followed them in 1858–59–60, of which the
noble Hartford was the chief, bore their full share in the war which
was so soon to come. The gallant Kearsarge was the leader of a new
class introduced in 1859.
During the Civil War two vessels, the Monitor and the New Ironsides,
appeared which have left lasting traces on all battleship construction
since their day. The great fleet of monitors, “tin-clads,” “90-day
gunboats,” “double-enders,” and the like, which preceded and followed
them during those dark years, served their country well. With the
ending of that war, in the internal task of reconstruction and
development, our maritime power was neglected and our fleet dwindled
away. Its _renaissance_ dates from the appointment of the first Naval
Advisory Board in June, 1881. The growth since then has been so much
a matter of national interest and pride that it needs no detailed
recounting here; its results have been summarized previously herein.
The sea-going personnel of the United States navy includes the
line, medical, pay, and marine officers, the chaplains and warrant
officers—a total on March 1, 1899, of 1589, with an enlisted force of
17,196 blue-jackets and 3166 marines. The officers who serve on shore
are the naval constructors, civil engineers, and the professors of
mathematics, a total of 69.
Line officers are the commanders, navigators, gunners, and, by recent
law, the engineers of our ships of war. Marine officers have charge
of the policing of ships and shore-stations and of the guns of light
calibre afloat. The duties of the remaining officers are indicated by
their titles. The titles of line officers and their relative rank, as
compared with that of officers of the army, are:—
NAVY. ARMY.
Admiral General.
Rear-Admiral Major or Brigadier-General.
Captain Colonel.
Commander Lieutenant-Colonel.
Lieutenant-Commander Major.
Lieutenant Captain.
Lieutenant Junior Grade First Lieutenant.
Ensign Second Lieutenant.
Line and marine officers and naval constructors are educated at
the United States Naval Academy; all other officers are appointed
from civil life. The Academy was founded in 1845 and is located at
Annapolis, Md. The course comprises four years at the school and two
years at sea on a naval vessel. The number of cadets at Annapolis is
usually about 260.
It is by reason of wars that navies exist, and a few words as to
our—now happily ended—conflict with Spain, may fitly close this
review of naval progress. The military lessons of that struggle
have been fully set forth by able writers. More important, by far,
than these is its teaching as regard to our state and future as a
nation. The world has learned that the people of these United States
are stirred still by the same stern and dauntless spirit which, in
Revolution and Civil War, has made and kept us a nation. Furthermore,
with one swift stroke, the bounds which in theory and in territory
circumscribed us have been swept away, and the United States have
passed from a continental to a world power. This is not chance. It is
but the leading onward to a destiny whose splendor we may not measure
now, whose light and peace and prosperity shall traverse a hemisphere.
The one note of sadness in it all is the memory of the gallant dead,
of the heroes who fell that this might be. To them, in Cuba and the
Philippines, Columbia—with a smile of pride and a sob of pain—drinks
in the wine of tears to-day, as the smoke of battle fades.
ASTRONOMY DURING THE CENTURY
BY SELDEN J. COFFIN, A.M.,
_Professor of Astronomy, Lafayette College, Easton, Pa._
ITS PROGRESS, ACHIEVEMENTS, AND NOTABLE RESULTS
Astronomy, the oldest of all the family of sciences, is not a whit
behind its sister branches in activity of research and brilliance of
discovery. The assiduity and zeal of its devotees are marvelous. The
celestial field is so wide, the depths of space between the stars so
vast, that no assurance can ever be given to an astronomer that a
lifetime of faithful and intelligent research will be rewarded with
even a single discovery of importance. In this respect it differs
materially from other branches of science.
Nevertheless the patient labor of those who serve in its temple has
rarely failed to receive an adequate reward. The discovery made in
August, 1877, by Professor Asaph Hall, of Washington, that the planet
Mars is attended by two satellites, is a convincing illustration
of this peculiarity of the pursuit of astronomy as a study. An
indefatigable watcher of the skies for many years, Professor Hall,
looking at this planet at its opposition in 1877, when it was unusually
near to the earth, was surprised to note two tiny points of light
quite close to it; seeing them again the next evening, changed in
their positions relative to Mars, it flashed upon him that the firm
tradition that Mars had no moons was now disproved. His name will
be forever associated with these two bodies, Deimos and Phobos, as
their discoverer, although they are but wee orbs, only seven miles in
diameter.
I. ASTRONOMY A CENTURY AGO.
The end of the eighteenth century found the Copernican theory of
astronomy well established, the principles laid down by Kepler and
Newton fully elaborated, and the application of the higher mathematics
to the needs of astronomy complete. But there were, as yet, no large
telescopes, and observatories were few. In Germany, a great disposition
to make observations in this science and in meteorology was displayed
in 1783 and for a few years following, and the records then made have
proved of much value in confirming discoveries announced at later
periods.
When Sir William Herschel, on March 13, 1781, pointed out a little star
in the constellation of the Twins, and found that it had a perceptible
disk and a slight motion, and was therefore not a star, but a newly
found planet, to which the name Uranus was soon given, a careful
inspection of the notebooks of previous observers showed that Uranus
had been observed and recorded as a fixed star on twenty previous
occasions in that century. One man had seen it twelve times, and made
his record of it on a paper bag purchased at a perfumer’s. Had he been
a man of sufficient order and method to have penned what he saw on the
regular records of his observatory, to him would have come the glory of
the great discovery of that century.
II. HOW “BODE’S LAW” PROMOTED RESEARCH.
An erroneous guess, if it is a good guess, sometimes produces excellent
results. In 1778, Bode, of Berlin, published a “law” that states the
distances of the various planets from the sun. It is often expressed
simply in this way: Set down 4, and add to it successively the numbers
3, 6, 12, 24, etc., and the sums obtained, viz., 4, 7, 10, 16, 28,
etc., represent the relative distances of all the planets from the
sun, viz., Mercury 4, Venus 7, Earth 10, Mars 16, [Asteroids 28],
Jupiter 52, etc. In reference to all the planets then known to exist,
the correspondence of the alleged law to the facts was remarkable. The
one point in which the alleged system utterly failed was in requiring
the existence of a planet to fill the gap between Mars and Jupiter. So
boldly did Biela press his convictions of the correctness of this law
upon the notice of his fellow-workers, that they resolved, in 1800,
to divide the zodiac into twenty-four zones, to be apportioned among
them, for the express purpose of searching for undiscovered planets.
This well-organized effort was, erelong, rewarded by the surprising
discovery of four new planets, the first one on the first night of
the new century, January 1, 1801, and three more soon after. As no
more seemed to be forthcoming, the search was relinquished in 1816.
A fifth was found in 1845, and nearly five hundred since. Since 1891
photography has been wondrously serviceable in finding these bodies.
A sensitive plate, on being exposed toward that part of the sky which
it is desired to examine, will record all the perceptible stars as
round disks; while any planets that appear in the field of view will,
by their motion, leave their trace in the form of elongated trails or
streaks, thus betraying themselves at once on the photographs. In this
way Charlois, of Nice, Italy, has found nearly ninety small planets.
All these planetoids, as the minor planets are often termed, are quite
small, being but twenty to one hundred miles in diameter, and not
consequential members of the solar system. Bode’s law thus fulfilled
its temporary mission; but egregiously failed when Neptune claimed
admission to a place in the solar system, for its distance from the sun
was utterly out of harmony with that required by the law of Bode.
III. HOW NEPTUNE WAS FOUND.
The patience of Job had a strong parallel in the labors of those
tireless toilers to whose minute computations we owe our knowledge of
Neptune’s path in the skies. For this far-off planet was discovered
not by the use of a telescope, or any optical instrument, but simply
by a process of mathematical reasoning. The story is simply this. For
sixty years after Uranus was recognized, there were irregularities in
its motion that could not be satisfactorily accounted for. In the orbit
that it was believed to pursue, it was sometimes in advance of its
proper position, and sometimes it seemed to fall behind. Sometimes it
appeared to be drawn a little to the right, and at other times as far
the other way.
The thought at last came separately to several penetrating minds, not
that the observations of its position were in error, but that Uranus
must be drawn away from its supposed path by the attraction exercised
upon it by some unseen body. And if such an object existed, was it
a planet? Where was it? How large was it? What was its path in the
far-off ether?
[Illustration: THE MOVEMENT OF URANUS AND NEPTUNE.
The inner circle shows the position of Uranus at various dates; the
outer circle the position of Neptune. The arrows show the direction
toward which Uranus was drawn.]
In the year 1842, the Royal Society of Sciences of Göttingen proposed
as a prize question the full discussion of the theory of the motions
of Uranus. It was specially sought to learn the cause of the large
and increasing error of Bouvard’s Tables that had been relied upon to
show its motion and its precise position at any time. Several able
mathematicians undertook this intricate problem. Among them were
John C. Adams, of Cambridge University, England, Sears C. Walker,
of Washington, a man whose sad fate it was to pass away ere his
magnificent abilities could receive extended recognition, and M. Le
Verrier, of Paris. Working unknown to each other, they reached similar
conclusions almost at the same time. Though not the first to solve
the problem, the brilliant Frenchman was the first to announce his
result, which he did by writing a letter to Dr. Galle, of the Berlin
Observatory, where there was one of the largest telescopes in Europe,
and asking him to search for his computed planet, and assigning its
supposed place in the heavens. The very night he received the letter
Dr. Galle found the planet within one degree of the point designated.
The next night it had moved one minute of space, and was also seen to
have a perceptible disk. This settled the question, and stamped it as
a planet. Le Verrier well merited the title bestowed upon him, “First
astronomer of the age.”
IV. METEORITES.
The nineteenth century will be forever memorable for its witnessing
the closing career and final destruction of a famous comet. First
noticed in France, in 1772, and rediscovered, in 1826, by an Austrian
officer named Biela, it bears his name. His computation showed that it
traversed its orbit in six and one half years. When it reappeared in
1846, and again in 1852, it was seen to have split into two unequal
fragments. It has not been seen since; but at every time when its
return should have taken place the earth has passed through showers of
meteors supposed to be its constituent particles, and to indicate its
entire disintegration.
During the meteoric shower of 1885, on the 27th of November, a large
iron meteorite fell in Mazapil, Mexico, and chemical and physical
investigation joined to pronounce it a part of the lost Biela’s comet.
The large cabinets of the world contain hundreds of specimens of
meteorites, known to be such by their chemical composition, but only
a few have actually been seen to fall. The most remarkable fall ever
witnessed was that of May 10, 1879, in Iowa, in which the heaviest
stone weighed 437 pounds. On April 8, 1893, an aerolite fell near
Osawatomie, Kansas, and struck the monument to John Brown that had
been erected through the efforts of Horace Greeley in 1863. The meteor
broke off the left arm of the statue. A Texas meteorite, owned by Yale
University, weighs 1635 pounds. A meteorite that fell in Jiminez, in
1892, now deposited in the city of Mexico, weighs twenty tons; and one
lying on the coast of Labrador, which it is proposed to bring to the
United States, is said to be still more massive.
V. DO METEORS OFTEN STRIKE THE EARTH?
It must not be thought that meteors usually strike the earth. In truth,
but few of them do. The earth is surrounded by them, cold, dark,
invisible, because unillumined. It is only when they become heated by
rapidly impinging on the atmosphere that they can be seen at all; and
unless they come near enough to become subject to the dominant power of
the earth’s attraction, they pass off into space unnoticed, and their
presence unsuspected.
[Illustration: JAMES H. COFFIN,
Late Professor of Astronomy, Lafayette College, Easton, Pa.]
A case in point is the brilliant “fire-ball” of July 20, 1860, that
moved rapidly over the United States, from Wisconsin to Cape Cod, and
then passed off into the skies. The entire time of its visible flight
over a path of thirteen hundred miles was about two minutes. It was
seen about ten o’clock in the evening. It was estimated to be from one
hundred to five hundred feet in diameter, allowing for an increase as
it expanded by reason of its striking with such velocity the lower
and denser layers of the air. Its size and brilliancy were such as to
arrest the attention of hundreds of persons, some of whom crouched in
fear, and even alleged that they heard it hiss as it flew over their
heads. Some fishermen in Lake Huron had ropes over the sides of their
boat, ready to spring into the water if it came too near.
James H. Coffin, LL. D., then Professor of Astronomy in Lafayette
College, made an exhaustive study of this unusual phenomenon, and,
under the patronage of the Smithsonian Institution, published a volume
containing many observations that he collected, with the mathematical
results derived from them. Professor J. Hann, of Vienna, the highest
authority on this subject, said that it was the most comprehensive
study of a meteor’s path ever accomplished. Six years were spent in
making the computations.
Self-illumined by the heat evolved in striking the various layers of
the earth’s atmosphere, it became sufficiently bright to be first seen
when seventy miles above the surface of the earth. It was within forty
miles of touching us at the time it was over the Hudson River, when
the great heat acquired by its rapid transit caused it to burst into
two masses, which—like Biela’s comet—continued to pursue separate
courses, side by side, until they were lost to view in their ascending
flight, being last seen from the deck of a vessel off the island of
Nantucket.
No part of the fire-ball struck the earth. Its orbit was an hyperbola,
a curve not often found in nature, such that it can never come near us
again unless, by the superior attraction of some celestial body, its
course may be changed, and a new orbit result.
VI. ASTRONOMICAL OBSERVATORIES.
The Royal Observatory, at Greenwich, England, was founded by Charles
the Second in 1675. Its main purpose was to extend astronomical
knowledge, so that navigators might better find the position of
their ships at sea. This institution retains its prominence. All the
longitudes on our maps are reckoned from it, and Greenwich time is used
on every ship that traverses the ocean. The “Nautical Almanac,” issued
by the Observatory, was an indispensable part of the outfit of every
sea captain until, in 1852, the United States provided its own American
Ephemeris, a collection of tables of the motions and places of the
sun, moon, and planets for every day and hour, and occultations of the
stars, with rules for calculating longitude and the like.
Many valuable observations of the transit of Venus in 1769 were made
at points near Philadelphia; but almost seventy years ensued before
America witnessed the erection of any permanent buildings devoted to
the purposes of this science.
President John Quincy Adams, who was highly versed in science, and held
the position of president of the American Academy of Arts and Sciences
in Boston for twenty years, often urged this matter on the attention of
Congress, but without success.
President Thomas Jefferson, who was also a man of no small scientific
information, as evidenced in his keeping a systematic weather record
at his home in Monticello, Virginia, proposed an elaborate survey of
the national coast. This was authorized by Congress in 1807. In the
year 1832, in reviving an act for the continuance of the Coast Survey,
Congress was careful to append the proviso “that nothing in the act
should be construed to authorize the erection or maintenance of a
permanent astronomical observatory.”