Part 7

The various modern submarine devices for the destruction of ships, known as torpedoes, submarine mines, etc., depend upon electricity for their efficiency. It is the lighting or firing agent, and is carried to the torpedo or mine by means of stout wires or cables from some safe shore-point of observation.

In railroading, electricity has become an indispensable agent for the operation of signal systems, opening and closing of switches, and limitation of safety sections. It moves the drill in the mine, sets off the blast, and supplies the light. It enables the dentist to manipulate his most delicate tools and do his cleanest and least painful work. In medicine it is a healing, soothing agent, boundless in variety of application and wondrous in results. It is a stimulus to the growth of certain plants, and has given rise to a new science called Electro-horticulture. It may be made a prolific source of heat for warming cars, and even for the welding of iron and steel. The electric fan cools our parlors and offices in summer, and the electric bell simplifies household service. In fact, it would appear that, in contrasting the electrical beginnings with the electrical endings of the nineteenth century, the space of a thousand rather than a hundred years had intervened, and that in measuring the agents which conduce to human comfort and convenience, electricity is easily the most potential.

X. ELECTRICAL LANGUAGE.

Out of the various discoveries and applications of electricity almost a new language has sprung. This is especially so of terms expressive of the measurements of electric energy, and of the laws governing the application of electric power. For a time, various nations measured and applied by means of terms chosen by themselves. This led to a jargon very confusing to writers and investigators. It became needful to have a language more in common, as in pharmacy, so that all nations could understand one another, could compute alike, and especially impart their meaning to those whose duty it became to apply discovered laws and actual calculations to practical electric operations. This was a difficult undertaking, owing to the tenacity with which nations clung to their own nomenclatures and terminologies. But the drift, though slow, finally ended at the Electrical Congress in Paris in 1881, in the adoption of a uniform system of measurements of electric force, and an agreement upon terms for laws and their application, which all could understand.

Three fundamental units of measurement were first agreed upon,—the _Centimetre_ (.394 in.) as a unit of length; the _Gramme_ (15.43 troy grains) as a unit of mass; the _Second_ (1/60 of a minute) as a unit of time. These three units became, when referred to together by their initial letters, the basis of the C. G. S. system of units. Now by these units of measurement something must be measured, as, for instance, the electric force; and when so measured, an absolute unit of force must be the result.

DYNE:—This is but a contraction of _dynam_, force. It was adopted as the name of the “Absolute Unit of Force,” or the C. G. S. unit of force, and is that force which, if it act for a second on one gramme of matter, gives to it a velocity of one centimetre per second.

AMPERE:—Electrical force produces electrical current. Current must be measured and an absolute unit of current strength agreed upon. The “Absolute Unit of Current” was settled as one of such strength as that when one centimetre length of its circuit is bent into an arc of one centimetre radius, the current in it exerts a force of one dyne on a unit magnet-pole placed at the centre. But the absolute unit of current as thus obtained was decided to be ten times too great for practical purposes. So a practical unit of current was fixed upon, which is just one tenth part of the above absolute unit of current. This practical unit of current was called the ampere, in honor of the celebrated French electrician, Ampère. It may be ascertained in other ways, as when a current is of sufficient strength to deposit in a copper electrolytic cell 1.174 grammes (18.116 grains) of copper in an hour, such current is said to be of one ampere strength; or a current of one ampere strength is such a one as would be given by an electro-motive force of one volt through a wire offering one ohm of resistance.

VOLT:—This was named from Volta, the celebrated Italian electrician, and was agreed upon as the unit of electro-motive force. It is that electro-motive force which would be generated by a conductor cutting across 100,000,000 C. G. S. lines in a field of force per second; or it is that electro-motive force which would carry one ampere of current against one ohm of resistance.

OHM:—So called from Ohm, a German electrician. It is the unit of resistance offered by a conductor to the passage of an electrical current. As an absolute unit of resistance, it is equal to 1,000,000,000 C. G. S. units of resistance. As a practical unit, and as agreed upon at the International Congress of Electricians (Chicago, 1893), it represents the resistance offered to an electric current at the temperature of melting ice by a column of mercury 14.451 grammes in mass, of a constant cross-sectional area, and 106.3 centimetres in length. This is called the international ohm. The resistance offered by 400 feet of ordinary telegraph wire is about an ohm.

These three units—ampere, volt, and ohm—are the factors in Ohm’s famous law that the current is directly proportional to the electro-motive force exerted in a circuit, and inversely proportional to the resistance of the circuit; that is,—

Current = Electro-motive force / Resistance

or,

Electro-motive force = Current × Resistance

or

Resistance = Electro-motive force / Current.

ERG:—From the Greek _ergon_, work, is the unit of work required to move a force of one dyne one centimetre. One foot-pound equals 13,560 ergs.

CALORIE:—Latin _calor_, heat, is the unit of heat; being the amount of heat required to raise the temperature of one kilogram of water one degree centigrade.

COULOMB:—In honor of C. A. de Coulomb, of France. It is the practical unit of quantity in measuring electricity, and is the amount conveyed by one ampere in one second.

FARAD:—From FARADAY, the physicist. It is the unit of electric capacity, and is the capacity of a condenser that retains one coulomb of charge with one volt difference of potential.

GAUSS:—From Carl F. Gauss (1785–1855). The C. G. S. unit of flux-density, or the unit by which the intensity of magnetic fields are measured. It equals one weber per normal square centimetre.

GILBERT:—The unit for measuring magneto-motive force, being produced by .7958 ampere-turn approximately.

HENRY:—From Joseph Henry, of the Smithsonian Institution, Washington, D. C. The practical unit for measuring the induction in a circuit when the electro-motive force induced is one international volt, while the inducing current varies at the rate of one ampere per second.

JOULE:—The C. G. S. unit of practical energy, being equivalent to the work done in keeping up for one second a current of one ampere against a resistance of one ohm. Named from J. P. Joule, of England.

OERSTED:—From Oersted, the electrician. It is the practical unit for measuring electrical reluctance.

WATT:—The practical electrical unit of the rate of working in a circuit, when the electro-motive force is one volt, and the intensity of current is one ampere. It is equal to 107 ergs per second, or .00134 horse-power per second. Named from James Watt, of Scotland.

WEBER:—The practical unit for measuring magnetic flux. Named from W. Weber, of Germany.

THE CENTURY’S NAVAL PROGRESS

BY REAR ADMIRAL GEORGE WALLACE MELVILLE, U. S. N.

I. INFLUENCE OF SEA POWER.

The share of navies in the great movements which have moulded human destiny and shaped the world’s progress, although long obscure and undervalued, has met in our time full recognition. Within a decade the influence of sea power upon history has become the frequent theme of historians and essayists who, in clear and striking form, have shown the cardinal importance, both in war and commerce, of the fleet—the nation’s right arm on the sea. It is fitting, therefore, that in the retrospect of a hundred years navies should have their place; that, in looking backward with history’s unclouded vision, we should mark, not only their growth and change, but, as well, their achievement in some of the most memorable conflicts of our race.

The century had but begun when, at Copenhagen, Nelson, with one titanic blow, shattered the naval strength of Denmark and the coalition of the Northern powers. His signal there, ever for “closer battle,” told in few words the life story of the Great Admiral, and foreshadowed his end. Four years later, at Trafalgar, the desire of his eager heart was satisfied, when he met in frank fight the fleets of France and Spain. Amid the thundering cannonade of that last victory his life-tide ebbed, bearing with it the power of France upon the seas and the broken fortunes of Napoleon. In the war of 1812, our disasters upon the land met compensation in victory afloat. The United States was then among the feeblest of maritime powers; and yet Macdonough and Perry on the lakes and our few frigates on the ocean opposed, with success, the swarming squadrons of a nation whose naval glory, as Hallam says, can be traced onward “in a continuous track of light” from the days of the Commonwealth. The oppression of the Sultan was ended for a time when, in 1827, the Turkish and Egyptian fleets were annihilated, in sudden fury, by the allied squadrons in that brief engagement which Wellington termed the “untoward event” of Navarino.

A generation later, the command of the sea enabled England and France to despatch, in unarmed transports, 63,000 men and 128 guns to the Crimea, and to land them, without opposition, for the red carnage of the Alma, Balaklava, Inkerman, and Sebastopol. Following closely upon the disease and death, the fatuity and the glory, of the Crimea, came the great war of modern times, in which the gun afloat played such a gallant part, as the blockade, with its constricting coils, slowly starved and strangled the Confederacy to death, and Farragut, on inland waters, split it in twain. Passing over the sea-fights of Lissa,—in which imperial Venice was the stake,—of South America and the Yalu, we note, lastly, the swift and fateful actions off Santiago and in Manila Bay, which destroyed once again the sea power of Spain, won distant territory for the United States, and opened up for us a noble pathway of commercial expansion to the uttermost island of the broad Pacific and the vast Asian littoral beyond. Who will say, in the retrospect of the century, that the fleets of the world have not had their full share in the making of its history?

II. THE CENTURY’S GROWTH IN NAVAL STRENGTH.

The United States fleet, in the year 1800, comprised 35 vessels, 10 of which were frigates mounting 32 guns or more. In 1812, America entered the lists against a navy of a thousand sail, with a fleet of but 20 ships, the largest of which was a 44-gun frigate. The operations of the Civil War were begun with but 82 vessels, 48 of which were sailing craft. Before the close of that gigantic struggle there were added, by construction or purchase, 674 steamers. In 1898, during the war with Spain, there were borne on the Naval Register, as building or in service, 13 battleships and 176 other vessels, including torpedo craft, with 123 converted merchantmen. The total naval force during hostilities was 22,832 men and 2382 officers, excluding the Marine Corps.

[Illustration: AN AUGUST MORNING WITH FARRAGUT.

(Battle of Mobile Bay.)]

At London, in 1653, there was printed “A List of the Commonwealth of England’s Navy at Sea, in their expedition in May, 1653, under the command of the Right Honorable Colonel Richard Deane and Colonel George Monk, Esquires, Generals, and Admirals.” This quaint record of that early time gives the force afloat as 105 ships, 3840 guns, and 16,269 men. In Britain’s strife for that ocean empire, which is world empire, that fleet had grown, by the year 1800, to 757 vessels, built or building, with an aggregate tonnage of 629,211, and carrying 26,552 guns, 3653 officers, and 110,000 men. The stately three-decker, with its snowy canvas and maze of rigging, has vanished with the past; but, despite time and change, that mighty fleet still dominates the seas. Its strength, on February 1, 1898, was 615 vessels—61 of which were battleships,—carrying a total force of 110,050 officers and men.

[Illustration: BRITISH BATTLESHIP MAJESTIC.]

[Illustration: FRENCH BATTLESHIP MAGENTA.]

Colbert, when the Grand Monarch was at the zenith of his power, found France with a few old and rotten vessels, and left her with a noble fleet of 40 ships of the line and 60 frigates, which, under D’Estrée, Jean Bart, Tourville, and Duquesne, carried her flag to every sea. A state paper of the time gives the force at the beginning of this century as 61 ships of the line, 42 corvettes, and a numerous, although unimportant, flotilla of small craft. With Aboukir and Trafalgar, the maritime power of France wasted away; and, by the year 1839, there were afloat but three effective sail of the line. In 1840, however, the revival began, and during the modern era the French fleet has, at times, been a formidable rival of that of England. It comprised, in 1898, 446 vessels, including torpedo craft, 26 of the total being battleships. The force afloat numbered 70,925, of all ranks and ratings.

[Illustration: GERMAN BATTLESHIP WOERTH.]

Germany’s navy is of modern creation. It began, a little less than half a century ago, with one sailing corvette and two gunboats; and, in 1898, comprised 13 battleships and 179 other vessels of all types, carrying 23,302 officers and men. The fleet of united Italy had its inception, also, within the age of steam. It was on March 17, 1860, that Italian national life began with the ascension of the throne by Victor Emmanuel. From the beginning, the kingdom has been lavish with its fleet, its expenditures within the first six years reaching $60,000,000. In 1898 there were in the Italian navy 265 vessels of all types, 17 of which were battleships. The force afloat was 24,200, of all ranks and ratings.

The Crimean war found Russia but little advanced, either on the Black Sea or the Baltic, in the substitution of steam for sail. Since that time, however, she has re-created her battle fleet, which is now especially strong in torpedo craft and cruisers of great steaming radius. Her navy, in 1898, comprised 20 battleships and 263 other vessels, with a force of 32,477 officers and men. Japan began her fleet in 1866 with the purchase of an armor-clad from the United States. In 1898, she had a total of 145 vessels, built and building—8 of which were battleships—carrying 23,000 men of all ranks and ratings.

[Illustration: ITALIAN BATTLESHIP SARDEGNA.]

Of minor navies little need be said. Austria had, in 1898, a fleet of 115 vessels of all types, including 13 battleships and 79 torpedo craft. Holland’s force was 185 vessels, 3 being battleships and 93 torpedo craft. The fleets of Turkey, Greece, Spain, and Portugal are “paper-navies” mainly. Norway and Sweden have a combined strength of 171 vessels of all types. Denmark, which began the century with overwhelming naval disaster at Copenhagen, has now a force of 3000 men borne on 50 vessels, half of which are torpedo craft. Argentina, Brazil, and Chili have afloat 102 torpedo vessels and 49 of other types. The vast growth in naval armaments during the century may be measured from the fact that the personnel of the leading navies of Europe, with those of Japan and the United States, comprised, in the year 1898, 368,028 officers and men, with a total force of 2749 vessels of all types, including torpedo craft.

III. THE BATTLESHIP,—PAST AND PRESENT.

In tracing the evolution of the modern man-of-war, it will be instructive to compare with her the type of the sailing age. There are two ships of the old time which hold chief places in the memory of the Anglo-Saxon race,—the Victory, Nelson’s flagship at Trafalgar, and the Constitution, whose achievements under Hull, Bainbridge, and Stewart, rang around the world. There were, even before the days of steam, war-vessels twice as large and powerful as “Old Ironsides,” but over no sea, in any age, has there sailed a ship with a more gallant record. Plate I shows her as she was in her prime—before the wind, with all sail set. On Plate II there is given a side view of her hull, which is of historic interest, in that it is reproduced from the original drawing made in October, 1796.

[Illustration: NELSON’S FLAGSHIP VICTORY.]

When her power and dimensions are compared with those of the Oregon, our sea-fighter of to-day, one sees what time has wrought. The frigate carried 456 men, the armor-clad, 500; and yet, with this approximately equal force, the Oregon has a displacement 6½ times that of her famed predecessor; and although the number of the guns—44—is the same in each, she discharges a broadside 8.3 times heavier and in energy overwhelmingly superior. The speed of the battleship is one half greater than that of the Constitution, and she carries armor varying from 18 inches to 4 inches thick, which the frigate wholly lacked. The longitudinal section of the Oregon indicates the immense advance in other directions. Her hull is, for safety, minutely subdivided, and is provided with engines for propulsion, steering, lighting, drainage, and ventilation, numbering in all 84, with miles of piping and hundreds of valves. The time-honored frigate was but a sail-propelled gun-platform, whose wants were as few as her construction was simple; the steel-clad battleship is a mass of mechanism, a floating machine-plant, which for full efficiency must be manned by a personnel not only brave and daring as of old, but expert in many arts and sciences, which in the age of sail were but rudimentary or unknown.

[Illustration: PLATE I. CONSTITUTION (1812) UNDER SAIL.]

IV. THE PROGRESS OF NAVAL ENGINEERING.

“_I have just read the project of Citizen Fulton, Engineer, which you have sent me much too late, since it is one which may change the face of the world._”

So, in the beginning of the century, wrote the first Napoleon from his Imperial camp at Boulogne. Wrapped in his day-dream of a descent upon the Thames, he saw, with prophetic vision, in the plans of the American engineer, the future of navigation, and he strove to grasp—but too late—the opportunity which might have made his armada victorious over wind and tide.

His words, however, rang truer than he knew. On the sea, as on the land, the engineer has indeed “changed the face of the world;” and in no department of human progress has his influence been more radical or more far-reaching than in the mechanism, the scope, and the strategy of naval war. Fleets move now with a swiftness and surety unthought of in the days of sail. Over the same western ocean which Nelson, in his eager chase of Villeneuve, crossed at but four knots an hour, the United States cruiser Columbia swept, ninety years later, at a speed nearly four and three quarters times that of his lagging craft. When, in 1898, war came, the great battleship Oregon, although far to the northward on our western coast, was needed in the distant battle-line off the Cuban shore. In 79 days she steamed 14,500 miles, making a run which is without parallel or approach by any warship of any navy in the world’s history. The magnificent manhood, the unconquerable pluck, the engineering skill, which brought her just in time off Santiago, won their reward when the Colon struck her flag. Speed has been a determining factor in many a naval action. It was that which gave the power to take and hold the old-time “weather-gauge.” None knew its value better than Nelson, the chief fighter of the age of sail. Once he said that there would be found, stamped upon his heart, “the want of frigates,” the swift and nimble “eyes of the fleet” in his day. If his career in warfare on the sea had been a century later, he would be found foremost among the advocates of high-speed battleships and quick-firing guns.

It is, however, not only in the speed of warships that steam and mechanism have revolutionized fleets. For example, the displacement of the battleship of to-day is fully three and one half times greater than that of her heaviest ancestor of the sailing age. With due limitation as to length of hull, it is evident that the wind would be, at best, a wholly inadequate and untrustworthy motor for this huge structure with its great weight of armor. It is true that, during the era of transition, sail and steam were both applied to iron-clads—this absurdity reaching its climax in the British Agincourt and her sisters, which were 400 feet long, 10,600 tons’ displacement, and were fitted with five masts. It is said that a merchant steamer narrowly escaped collision at night with one of these vessels, believing from her length and rigging that there were _two_ ships ahead, between which she could pass. What these large displacements mean, in contrast with those of past days, will be, perhaps, best illustrated by the statement that the Italia of 13,600 tons—a ship with which, in her day, Italy challenged the criticism of the world—carries on her deck a weight, in armor and armament, of 2500 tons, or one fourth more than that of Nelson’s flagship Victory.

[Illustration: PLATE II. SIDE VIEW OF CONSTITUTION FROM ORIGINAL DRAWING.

(Furnished by the Author.)

Length 174 ft. 10½ ins. Beam 43 ft. 6 in. Mean Draught 20 ft. 0 in. Displacement 2200 tons.

WILLIAM DOUGHTY, Fecit. 1796, Oct.

Joshua Humphreys, of Philadelphia, Designer. Cloghorne and Hartley, of Boston, Builders. Launched Oct. 21, 1797.]

Again, the largest naval gun in the year 1800 was one firing but a 42-pound shot, while in the United States navy we have now the 13-inch rifle of 60 tons, with a projectile of 1100 pounds, and Great Britain has afloat 1800-pounder breech-loaders which weigh 111 tons. Before monster ordnance such as this, the strength of man, unaided, is but crude and futile. He must call to his help—as he has done—steam as the source of power for the electric, hydraulic, or pneumatic engines, which load, elevate, and train the gun.

In summing up the service of steam, directly or indirectly, to the ship-of-war, it will be seen that the speed of the battleship has been increased by fully 50 per cent., and that of the cruiser has been doubled; that the displacement of the battleship is now three and one half times that of her sailing predecessor; and that, since the century’s birth, the gun has grown to such extent that the projectile for the Oregon’s main battery weighs 26 times that of the heaviest shot in the year 1800. This, however, is not all. Steam acts primarily, as well, to raise the anchor, to steer the ship, and to effect her lighting, heating, drainage, and ventilation. To the genius of James Watt there must be ascribed the possibility for the growth and change which have produced the modern man-of-war.