The astonishing things of to-day are the commonplaces of to-morrow, and so the achievements of automobile builders as here set down may be greatly surpassed by the time this appears in print.

The sensations of the locomotive engineer, who feels his great machine strain forward over the smooth steel rails, are as nothing to the almost numbing sensations of the automobile driver who covered space at the rate of eighty-eight miles an hour on the road between Paris and Madrid: he felt every inequality in the road, every grade along the way, and each curve, each shadow, was a menace that required the greatest nerve and skill. Locomotive driving at a hundred miles an hour is but mild exhilaration as compared to the feelings of the motor-car driver who travels at fifty miles an hour on the public highway.

Gigantic motor trucks carrying tons of freight twist in and out through crowded streets, controlled by one man more easily than a driver guides a spirited horse on a country road.

Frail motor bicycles dash round the platter-like curves of cycle tracks at railroad speed, and climb hills while the riders sit at ease with feet on coasters.

An electric motor-car wends the streets of New York every day with thirty-five or forty sightseers on its broad back, while a groom in whipcord blows an incongruous coaching-horn in the rear.

Motor plows, motor ambulances, motor stages, delivery wagons, street-cars without tracks, pleasure vehicles, and even baby carriages, are to be seen everywhere.

In 1845, motor vehicles were forbidden the streets for the sake of the horses; in 1903, the horses are being crowded off by the motor-cars. The motor is the more economical—it is the survival of the fittest.



THE FASTEST STEAMBOATS

In 1807, the first practical steamboat puffed slowly up the Hudson, while the people ranged along the banks gazed in wonder. Even the grim walls of the Palisades must have been surprised at the strange intruder. Robert Fulton's Clermont was the forerunner of the fleets upon fleets of power-driven craft that have stemmed the currents of a thousand streams and parted the waves of many seas.

The Clermont took several days to go from New York to Albany, and the trip was the wonder of that time.

During the summer of 1902 a long, slim, white craft, with a single brass smokestack and a low deck-house, went gliding up the Hudson with a kind of crouching motion that suggested a cat ready to spring. On her deck several men were standing behind the pilot-house with stop-watches in their hands. The little craft seemed alive under their feet and quivered with eagerness to be off. The passenger boats going in the same direction were passed in a twinkling, and the tugs and sailing vessels seemed to dwindle as houses and trees seem to shrink when viewed from the rear platform of a fast train.

Two posts, painted white and in line with each other—one almost at the river's edge, the other 150 feet back—marked the starting-line of a measured mile, and were eagerly watched by the men aboard the yacht. She sped toward the starting-line as a sprinter dashes for the tape; almost instantly the two posts were in line, the men with watches cried "Time!" and the race was on. Then began such a struggle with Father Time as was never before seen; the wind roared in the ears of the passengers and snatched their words away almost before their lips had formed them; the water, a foam-flecked streak, dashed away from the gleaming white sides as if in terror. As the wonderful craft sped on she seemed to settle down to her work as a good horse finds himself and gets into his stride. Faster and faster she went, while the speed of her going swept off the black flume of smoke from her stack and trailed it behind, a dense, low-lying shadow.

"Look!" shouted one of the men into another's ear, and raised his arm to point. "We're beating the train!"



Sure enough, a passenger train running along the river's edge, the wheels spinning round, the locomotive throwing out clouds of smoke, was dropping behind. The train was being beaten by the boat. Quivering, throbbing with the tremendous effort, she dashed on, the water climbing her sides and lashing to spume at her stern.

"Time!" shouted several together, as the second pair of posts came in line, marking the finish of the mile. The word was passed to the frantically struggling firemen and engineers below, while those on deck compared watches.

"One minute and thirty-two seconds," said one.

"Right," answered the others.

Then, as the wonderful yacht Arrow gradually slowed down, they tried to realise the speed and to accustom themselves to the fact that they had made the fastest mile on record on water.

And so the Arrow, moving at the rate of forty-six miles an hour, followed the course of her ancestress, the Clermont, when she made her first long trip almost a hundred years before.

The Clermont was the first practical steamboat, and the Arrow the fastest, and so both were record-breakers. While there are not many points of resemblance between the first and the fastest boat, one is clearly the outgrowth of the other, but so vastly improved is the modern craft that it is hard to even trace its ancestry. The little Arrow is a screw-driven vessel, and her reciprocating engines—that is, engines operated by the pulling and pushing power of the steam-driven pistons in cylinders—developed the power of 4,000 horses, equal to 32,000 men, when making her record-breaking run. All this enormous power was used to produce speed, there being practically no room left in the little 130-foot hull for anything but engines and boilers.

There is little difference, except in detail, between the Arrow's machinery and an ordinary propeller tugboat. Her hull is very light for its strength, and it was so built as to slip easily through the water. She has twin engines, each operating its own shaft and propeller. These are quadruple expansion. The steam, instead of being allowed to escape after doing its work in the first cylinder, is turned into a larger one and then successively into two more, so that all of its expansive power is used. After passing through the four cylinders, the steam is condensed into water again by turning it into pipes around which circulates the cool water in which the vessel floats. The steam thus condensed to water is heated and pumped into the boiler, to be turned into steam, so the water has to do its work many times. All this saves weight and, therefore, power, for the lighter a vessel is the more easily she can be driven. The boilers save weight also by producing steam at the enormous pressure of 400 pounds to the square inch. Steadily maintained pressure means power; the greater the pressure the more the power. It was the inventive skill of Charles D. Mosher, who has built many fast yachts, that enabled him to build engines and boilers of great power in proportion to their weight. It was the ability of the inventor to build boilers and engines of 4,000 horse-power compact and light enough to be carried in a vessel 130 feet long, of 12 feet 6 inches breadth, and 3 feet 6 inches depth, that made it possible for the Arrow to go a mile in one minute and thirty-two seconds. The speed of the wonderful little American boat, however, was not the result of any new invention, but was due to the perfection of old methods.

In England, about five years before the Arrow's achievement, a little torpedo-boat, scarcely bigger than a launch, set the whole world talking by travelling at the rate of thirty-nine and three-fourths miles an hour. The little craft seemed to disappear in the white smother of her wake, and those who watched the speed trial marvelled at the railroad speed she made. The Turbina—for that was the little record-breaker's name—was propelled by a new kind of engine, and her speed was all the more remarkable on that account. C.A. Parsons, the inventor of the engine, worked out the idea that inventors have been studying for a long time—since 1629, in fact—that is, the rotary principle, or the rolling movement without the up-and-down driving mechanism of the piston.

The Turbina was driven by a number of steam-turbines that worked a good deal like the water-turbines that use the power of Niagara. Just as a water-wheel is driven by the weight or force of the water striking the blades or paddles of the wheel, so the force of the many jets of steam striking against the little wings makes the wheels of the steam-turbines revolve. If you take a card that has been cut to a circular shape and cut the edges so that little wings will be made, then blow on this winged edge, the card will revolve with a buzz; the Parsons steam-turbine works in the same way. A shaft bearing a number of steel disks or wheels, each having many wings set at an angle like the blades of a propeller, is enclosed by a drumlike casing. The disks at one end of the shaft are smaller than those at the other; the steam enters at the small end in a circle of jets that blow against the wings and set them and the whole shaft whirling. After passing the first disk and its little vanes, the steam goes through the holes of an intervening fixed partition that deflects it so that it blows afresh on the second, and so on to the third and fourth, blowing upon a succession of wheels, each set larger than the preceding one. Each of Parsons's steam-turbine engines is a series of turbines put in a steel casing, so that they use every ounce of the expansive power of the steam.

It will be noticed that the little wind-turbine that you blow with your breath spins very rapidly; so, too, do the wheels spun by the steamy breath of the boilers, and Mr. Parsons found that the propeller fastened to the shaft of his engine revolved so fast that a vacuum was formed around the blades, and its work was not half done. So he lengthened his shaft and put three propellers on it, reducing the speed, and allowing all of the blades to catch the water strongly.

The Turbina, speeding like an express train, glided like a ghost over the water; the smoke poured from her stack and the cleft wave foamed at her prow, but there was little else to remind her inventor that 2,300 horse-power was being expended to drive her. There was no jar, no shock, no thumping of cylinders and pounding of rapidly revolving cranks; the motion of the engine was rotary, and the propeller shafts, spinning at 2,000 revolutions per minute, made no more vibration than a windmill whirling in the breeze.

To stop the Turbina was an easy matter; Mr. Parsons had only to turn off the steam. But to make the vessel go backward another set of turbines was necessary, built to run the other way, and working on the same shaft. To reverse the direction, the steam was shut off the engines which revolved from right to left and turned on those designed to run backward, or from left to right. One set of the turbines revolved the propellers so that they pushed, and the other set, turning them the other way, pulled the vessel backward—one set revolving in a vacuum and doing no work, while the other supplied the power.

The Parsons turbine-engines have been used to propel torpedo-boats, fast yachts, and vessels built to carry passengers across the English Channel, and recently it has been reported that two new transatlantic Cunarders are to be equipped with them.



A few years after the Pilgrims sailed for the land of freedom in the tiny Mayflower a man named Branca built a steam-turbine that worked in a crude way on the same principle as Parsons's modern giant. The pictures of this first steam-turbine show the head and shoulders of a bronze man set over the flaming brands of a wood fire; his metallic lungs are evidently filled with water, for a jet of steam spurts from his mouth and blows against the paddles of a horizontal turbine wheel, which, revolving, sets in motion some crude machinery.

There is nothing picturesque about the steel-tube lungs of the boilers used by Parsons in the Turbina and the later boats built by him, and plain steel or copper pipes convey the steam to the whirling blades of the enclosed turbine wheels, but enormous power has been generated and marvellous speed gained. In the modern turbine a glowing coal fire, kept intensely hot by an artificial draft, has taken the place of the blazing sticks; the coils of steel tubes carrying the boiling water surrounded by flame replace the bronze-figure boiler, and the whirling, tightly jacketed turbine wheels, that use every ounce of pressure and save all the steam, to be condensed to water and used over again, have grown out of the crude machine invented by Branca.

As the engines of the Arrow are but perfected copies of the engine that drove the Clermont, so the power of the Turbina is derived from steam-motors that work on the same principle as the engine built by Branca in 1629, and his steam-turbine following the same old, old, ages old idea of the moss-covered, splashing, tireless water-wheel.



THE LIFE-SAVERS AND THEIR APPARATUS

Forming the outside boundary of Great South Bay, Long Island, a long row of sand-dunes faces the ocean. In summer groups of laughing bathers splash in the gentle surf at the foot of the low sand-hills, while the sun shines benignly over all. The irregular points of vessels' sails notch the horizon as they are swept along by the gentle summer breezes. Old Ocean is in a playful mood, and even children sport in his waters.

After the last summer visitor has gone, and the little craft that sail over the shallow bay have been hauled up high and dry, the pavilions deserted and the bathing-houses boarded up, the beaches take on a new aspect. The sun shines with a cold gleam, and the surf has an angry snarl to it as it surges up the sandy slopes and then recedes, dragging the pebbles after it with a rattling sound. The outer line of sand-bars, which in summer breaks the blue sea into sunny ripples and flashing whitecaps, then churns the water into fury and grips with a mighty hold the keel of any vessel that is unlucky enough to be driven on them. When the keen winter winds whip through the beach grasses on the dunes and throw spiteful handfuls of cutting sand and spray; when the great waves pound the beach and the crested tops are blown off into vapour, then the life-saver patrolling the beach must be most vigilant.

All along the coast, from Maine to Florida, along the Gulf of Mexico, the Great Lakes, and the Pacific, these men patrol the beach as a policeman walks his beat. When the winds blow hardest and sleet adds cutting force to the gale, then the surfmen, whose business it is to save life regardless of their own comfort or safety, are most alert.

All day the wind whistled through the grasses and moaned round the corners of the life-saving station; the gusts were cold, damp, and penetrating. With the setting of the sun there was a lull, but when the patrols started out at eight o'clock, on their four-hours' tour of duty, the wind had risen again and was blowing with renewed force. Separating at the station, one surf man went east and the other west, following the line of the surf-beaten beach, each carrying on his back a recording clock in a leather case, and also several candle-like Coston lights and a wooden handle.



"Wind's blowing some," said one of the men, raising his voice above the howl of the blast.

"Hope nothing hits the bar to-night," the other answered. Then both trudged off in opposite directions.

With pea-coats buttoned tightly and sou'westers tied down securely, the surfmen fought the gale on their watch-tour of duty. At the end of his beat each man stopped to take a key attached to a post, and, inserting it in the clock, record the time of his visit at that spot, for by this means is an actual record kept of the movements of the patrol at all times.

With head bent low in deference to the force of the blast, and eyes narrowed to slits, the surfman searched the seething sea for the shadowy outlines of a vessel in trouble.

Perchance as he looked his eye caught the dark bulk of a ship in a sea of foam, or the faint lines of spars and rigging through the spume and frozen haze—the unmistakable signs of a vessel in distress. An instant's concentrated gaze to make sure, then, taking a Coston signal from his pocket and fitting it to the handle, he struck the end on the sole of his boot. Like a parlour match it caught fire and flared out a brilliant red light. This served to warn the crew of the vessel of their danger, or notified them that their distress was observed and that help was soon forthcoming; it also served, if the surfman was near enough to the station, to notify the lookout there of the ship in distress. If the distance was too great or the weather too thick, the patrol raced back with all possible speed to the station and reported what he had seen. The patrol, through his long vigils under all kinds of weather conditions, learns every foot of his beat thoroughly, and is able to tell exactly how and where a stranded vessel lies, and whether she is likely to be forced over on to the beach or whether she will stick on the outer bar far beyond the reach of a line shot from shore.

In a few words spoken quickly and exactly to the point—for upon the accuracy of his report much depends—he tells the situation. For different conditions different apparatus is needed. The vessel reported one stormy winter's night struck on the shoal that runs parallel to the outer Long Island beach, far beyond the reach of a line from shore. Deep water lies on both sides of the bar, and after the shoal is passed the broken water settles down a little and gathers speed for its rush for the beach. These conditions were favourable for surf-boat work, and as the surfman told his tale the keeper or captain of the crew decided what to do.

The crew ran the ever-ready surf-boat through the double doors of its house down the inclined plane to the beach. Resting in a carriage provided with a pair of broad-tired wheels, the light craft was hauled by its sturdy crew through the clinging sand and into the very teeth of the storm to the point nearest the wreck.

The surf rolled in with a roar that shook the ground; fringed with foam that showed even through that dense midnight darkness, the waves were hungry for their prey. Each breaker curved high above the heads of the men, and, receding, the undertow sucked at their feet and tried to drag them under. It did not seem possible that a boat could be launched in such a sea. With scarcely a word of command, however, every man, knowing from long practice his position and specific duties, took his station on either side of the buoyant craft and, rushing into the surf, launched her; climbing aboard, every man took his appointed place, while the keeper, a long steering-oar in his hands, stood at the stern. All pulled steadily, while the steersman, with a sweep of his oar, kept her head to the seas and with consummate skill and judgment avoided the most dangerous crests, until the first watery rampart was passed. Adapting their stroke to the rough water, the six sturdy rowers propelled their twenty-five-foot unsinkable boat at good speed, though it seemed infinitely slow when they thought of the crew of the stranded vessel off in the darkness, helpless and hopeless. Each man wore a cork jacket, but in spite of their encumbrances they were marvellously active.

As is sometimes the case, before the surf-boat reached the distressed vessel she lurched over the bar and went driving for the beach.

The crew in the boat could do nothing, and the men aboard the ship were helpless. Climbing up into the rigging, the sailors waited for the vessel to strike the beach, and the life-savers put for shore again to get the apparatus needed for the new situation. To load the surf-boat with the wrecked, half-frozen crew of the stranded vessel, when there was none too much room for the oarsmen, and then encounter the fearful surf, was a method to be pursued only in case of dire need. To reach the wreck from shore was a much safer and surer method of saving life, not only for those on the vessel, but also for the surfmen.

The beach apparatus has received the greatest attention from inventors, since that part of the life-savers' outfit is depended upon to rescue the greatest number.

With a rush the surf-boat rolled in on a giant wave amid a smother of foam, and no sooner had her keel grated on the sand than her crew were out knee-deep in the swirling water and were dragging her up high and dry.

A minute later the entire crew, some pulling, some steering, dragged out the beach wagon. A light framework supported by two broad-tired wheels carried all the apparatus for rescue work from the beach. Each member of the crew had his appointed place and definite duties, according to printed instructions which each had learned by heart, and when the command was given every man jumped to his place as a well-trained man-of-war's-man takes his position at his gun.

Over hummocks of sand and wreckage, across little inlets made by the waves, in the face of blinding sleet and staggering wind, the life-savers dragged the beach wagon on the run.

Through the mist and shrouding white of the storm the outlines of the stranded vessel could just be distinguished.

Bringing the wagon to the nearest point, the crew unloaded their appliances.

Two men then unloaded a sand-anchor—an immense cross—and immediately set to work with shovels to dig a hole in the sand and bury it. While this was being done two others were busy placing a bronze cannon (two and one-half-inch bore) in position; another got out boxes containing small rope wound criss-cross fashion on wooden pins set upright in the bottom. The pins merely held the rope in its coils until ready for use, when board and pegs were removed. The free end of the line was attached to a ring in the end of the long projectile which the captain carried, together with a box of ammunition slung over his shoulders. The cylindrical projectile was fourteen and one-half inches long and weighed seventeen pounds. All these operations were carried on at once and with utmost speed in spite of the great difficulties and the darkness.

While the surf boomed and the wind roared, the captain sighted the gun—aided by Nos. 1 and 2 of the crew—aiming for the outstretched arms of the yards of the wrecked vessel. With the wind blowing at an almost hurricane rate, it was a difficult shot, but long practice under all kinds of difficulties had taught the captain just how to aim. As he pulled the lanyard, the little bronze cannon spit out fire viciously, and the long projectile, to which had been attached the end of the coiled line, sailed off on its errand of mercy. With a whir the line spun out of the box coil after coil, while the crew peered out over the breaking seas to see if the keeper's aim was true. At last the line stopped uncoiling and the life-savers knew that the shot had landed somewhere. For a time nothing happened, the slender rope reached out into the boiling waves, but no answering tugs conveyed messages to the waiting surfmen from the wrecked seamen.

At length the line began to slip through the fingers of the keeper who held it and moved seaward, so those on shore knew that the rope had been found and its use understood. The line carried out by the projectile served merely to drag out a heavy rope on which was run a sort of trolley carrying a breeches-buoy or sling.

The men on the wreck understood the use of the apparatus, or read the instructions printed in several languages with which the heavy rope was tagged. They made the end of the strong line fast to the mast well above the reach of the hungry seas, and the surfmen secured their end to the deeply buried sand-anchor, an inverted V-shaped crotch placed under the rope holding it above the water on the shore end. When this had been done, as much of the slack was taken up as possible, and the wreck was connected with the beach with a kind of suspension bridge.

All this occupied much time, for the hands of the sailors were numb with cold, the ropes stiff with ice, while the wild and angry wind snatched at the tackle and tore at the clinging figures.

In a trice the willing arms on shore hauled out the buoy by means of an endless line reaching out to the wreck and back to shore. Then with a joy that comes only to those who are saving a fellow-creature from death, the life-savers saw a man climb into the stout canvas breeches of the hanging buoy, and felt the tug on the whip-line that told them that the rescue had begun. With a will they pulled on the line, and the buoy, carrying its precious burden, rolled along the hawser, swinging in the wind, and now and then dipping the half-frozen man in the crests of the waves. It seemed a perilous journey, but as long as the wreck held together and the mast remained firmly upright the passengers on this improvised aerial railway were safe.

One after the other the crew were taken ashore in this way, the life-savers hauling the breeches-buoy forward and back, working like madmen to complete their work before the wreck should break up. None too soon the last man was landed, for he had hardly been dragged ashore when the sturdy mast, being able to stand the buffeting of the waves no longer, toppled over and floated ashore.

The life-savers' work is not over when the crew of a vessel is saved, for the apparatus must be packed on the beach wagon and returned to the station, while the shipwrecked crew is provided with dry clothing, fed, and cared for. The patrol continues on his beat throughout the night without regard to the hardships that have already been undergone.

The success of the surfmen in saving lives depends not only on their courage and strength, supplemented by continuous training which has been proved time and again, but the wonderful record of the life-saving service is due as well to the efficient appliances that make the work of the men effective.

Besides the apparatus already described, each station is provided with a kind of boat-car which has a capacity for six or seven persons, and is built so that its passengers are entirely enclosed, the hatch by which they enter being clamped down from the inside. When there are a great many people to be saved, this car is used in place of the breeches-buoy. It is hung on the hawser by rings at either end and pulled back and forth by the whip-line; or, if the masts of the vessel are carried away and there is nothing to which the heavy rope can be attached so that it will stretch clear above the wave-crests, in such an emergency the life-car floats directly on the water, and the whip-line is used to pull it to the shore with wrecked passengers and back to the wreck for more.

Everything that would help to save life under any condition is provided, and a number of appliances are duplicated in case one or more should be lost or damaged at a critical time. Signal flags are supplied, and the surfmen are taught their use as a means of communicating with people aboard a vessel in distress. Telephones connect the stations, so that in case of any special difficulty two or even three crews may be combined. When wireless telegraphy comes into general use aboard ship the stations will doubtless be equipped with this apparatus also, so that ships may be warned of danger.



The 10,000 miles of the United States ocean, gulf, and Great Lakes coasts, exclusive of Alaska and the island possessions, are guarded by 265 stations and houses of refuge at this writing, and new ones are added every year. Practically all of this immense coast-line is patrolled or watched over during eight or nine stormy months, and those that "go down to the sea in ships" may be sure of a helping hand in time of trouble.

The dangerous coasts are more thickly studded with stations, and the sections that are comparatively free from life-endangering reefs are provided with refuge houses where supplies are stored and where wrecked survivors may find shelter.

The Atlantic coast, being the most dangerous to shipping, is guarded by more than 175 stations; the Great Lakes require fifty or more to care for the survivors of the vessels that are yearly wrecked on their harbourless shores. For the Gulf of Mexico eight are considered sufficient, and the long Pacific coast also requires but eight.

The Life-Saving Service, formerly under the Treasury Department, now an important part of the Department of Commerce and Labour, was organised by Sumner I. Kimball, who was put at its head in 1871, and the great success and glory it has won is largely due to his energy and efficient enthusiasm.

The Life-Saving Service publishes a report of work accomplished through the year. It is a dry recital of facts and figures, but if the reader has a little imagination he can see the record of great deeds of heroism and self-sacrifice written between the lines.

As vessels labour through the wintry seas along our coasts, and the on-shore winds roar through the rigging, while the fog, mist or snow hangs like a curtain all around, it is surely a comfort to those at sea to know that all along the dangerous coast men specially trained, and equipped with the most efficient apparatus known, are always ready to stretch out a helping hand.



MOVING PICTURES

Some Strange Subjects and How They Were Taken

The grandstand of the Sheepshead Bay race-track, one spring afternoon, was packed solidly with people, and the broad, terra-cotta-coloured track was fenced in with a human wall near the judges' stand. The famous Suburban was to be run, and people flocked from every direction to see one of the greatest horse-races of the year. While the band played gaily, and the shrill cries of programme venders punctuated the hum of the voices of the multitude, and while the stable boys walked their aristocratic charges, shrouded in blankets, exercising them sedately—in the midst of all this movement, hubbub, and excitement a man a little to one side, apparently unconscious of all the uproar, was busy with a big box set up on a portable framework six or seven feet above the ground. The man was a new kind of photographer, and his big box was a camera with which he purposed to take a series of pictures of the race. Above the box, which was about two and a half feet square, was an electric motor from which ran a belt connecting with the inner mechanism; from the front of the box protruded the lens, its glassy eye so turned as to get a full sweep of the track; nearby on the ground were piled the storage batteries which were used to supply the current for the motor.

As the time for the race drew near the excitement increased, figures darted here, there and everywhere, the bobbing, brightly coloured hats of the women in the great slanting field of the grandstand suggesting bunches of flowers agitated by the breeze. Then the horses paraded in a thoroughbred fashion, as if they appreciated their lengthy pedigrees and understood their importance.

At last the splendid animals were lined up across the track, their small jockeys in their brilliantly coloured jackets hunched up like monkeys on their backs. Then the enormous crowd was quiet, the band was still, even the noisy programme venders ceased calling their wares, and the photographer stood quietly beside his camera, the motor humming, his hand on the switch that starts the internal machinery. Suddenly the starter dropped his arm, the barring gate flew up, and the horses sprang forward. "They're off!" came from a thousand throats in unison. The band struck up a lively air, and the vast assemblage watched with excited eyes the flying horses. As the horses swept on round the turn and down the back stretch the people seemed to be drawn from their seats, and by the time the racers made the turn leading into the home-stretch almost every one was standing and the roar of yelling voices was deafening.

All this time the photographer kept his eyes on his machine, which was rattling like a rapidly beaten drum, the cyclopean eye of the camera making impressions on a sensitised film-ribbon at the rate of forty a second, and every movement of the flying legs of the urging jockeys, even the puffs of dust that rose at the falling of each iron-shod hoof, was recorded for all time by the eye of the camera.

The horses entered the home-stretch and in a terrific burst of speed flashed by the throngs of yelling people and under the wire, a mere blur of shining bodies, brilliant colours of the jockeys' blouses, and yellow dust. The Suburban was over, and the great crowd that had come miles to see a race that lasted but a little more than two minutes (a grand struggle of giants, however), sank back into their seats or relaxed their straining gaze in a way that said plainer than words could say it, "It is over."

It was 4:45 in the afternoon. The photographer was all activity. The minute the race was over the motor above the great camera was stopped and the box was opened. From its dark interior another box about six inches square and two inches deep was taken: this box contained the record of the race, on a narrow strip of film two hundred and fifty feet long, the latent image of thousands of separate pictures.

Then began another race against time, for it was necessary to take that long ribbon across the city of Brooklyn, over the Bridge, across New York, over the North River by ferry to Hoboken on the Jersey side, develop, fix, and dry the two-hundred-and-fifty-foot-long film-negative, make a positive or reversed print on another two-hundred-and-fifty-foot film, carry it through the same photographic process, and show the spirited scene on the stereopticon screen of a metropolitan theatre the same evening.

That evening a great audience in the dark interior of a New York theatre sat watching a white sheet stretched across the stage; suddenly its white expanse grew dark, and against the background appeared "The Suburban, run this afternoon at 4:45 at Sheepshead Bay track; won by Alcedo, in 2 minutes 5 3-5 seconds."



Then appeared on the screen the picture of the scene that the thousands had travelled far to see that same afternoon. There were the wide, smooth track, the tower-like judges' stand, the oval turf of the inner field, and as the audience looked the starter moved his arm, and the rank of horses, life-size and quivering with excitement, shot forth. From beginning to end the great struggle was shown to the people seated comfortably in the city playhouse, several miles from the track where the race was run, just two hours and fifteen minutes after the winning horse dashed past the judges' stand. Every detail was reproduced; every movement of horses and jockeys, even the clouds of dust that rose from the hoof-beats, appeared clearly on the screen. And the audience rose gradually to their feet, straining forward to catch every movement, thrilled with excitement as were the mighty crowds at the actual race.

To produce the effect that made the people in the theatre forget their surroundings and feel as if they were actually overlooking the race-track itself, about five thousand separate photographs were shown.

It was discovered long ago that if a series of pictures, each of which showed a difference in the position of the legs of a man running, for instance, was passed quickly before the eye so that the space between the pictures would be screened, the figure would apparently move. The eyes retain the image they see for a fraction of a second, and if a new image carrying the movement a little farther along is presented in the same place, the eyes are deceived so that the object apparently actually moves. An ingenious toy called the zoltrope, which was based on this optical illusion, was made long before Edison invented the vitascope, Herman Caster the biograph and mutoscope, or the Lumiere brothers in France devised the cinematograph. All these different moving-picture machines work on the same principle, differing only in their mechanism.

A moving-picture machine is really a rapid-fire repeating camera provided with a lens allowing of a very quick exposure. Internal mechanism, operated by a hand-crank or electric motor, moves the unexposed film into position behind the lens and also opens and closes the shutter at just the proper moment. The same machinery feeds down a fresh section of the ribbon-like film into position and coils the exposed portion in a dark box, just as the film of a kodak is rolled off one spool and, after exposure, is wound up on another. The film used in the biograph when taking the Suburban was two and three-fourth inches wide and several hundred feet long; about forty exposures were made per second, and for each exposure the film had to come to a dead stop before the lens and then the shutter was opened, the light admitted for about one three-hundredth of a second, the shutter closed, and a new section of film moved into place, while the exposed portion was wound upon a spool in a light-tight box. The long, flexible film is perforated along both edges, and these perforations fit over toothed wheels which guide it down to the lens; the holes in the celluloid strip are also used by the feeding mechanism. In order that the interval between the pictures shall always be the same, the film must be held firmly in each position in turn; the perforations and toothed mechanism accomplish this perfectly.

In taking the picture of the Suburban race almost five thousand separate negatives (all on one strip of film, however) were made during the two minutes five and three-fifths seconds the race was being run. Each negative was perfectly clear, and each was different, though if one negative was compared to its neighbour scarcely any variance would be noted.

After the film has been exposed, the light-tight box containing it is taken out of the camera and taken to a gigantic dark-room, where it is wound on a great reel and developed, just as the image on a kodak film is brought out. The reel is hung by its axle over a great trough containing gallons of developer, so that the film wound upon it is submerged; and as the reel is revolved all of the sensitised surface is exposed to the action of the chemicals and gradually the latent pictures are developed. After the development has gone far enough, the reel, still carrying the film, is dipped in clean water and washed, and then a dip in a similar bath of clearing-and-fixing solution makes the negatives permanent—followed by a final washing in clean water. It is simply developing on a grand scale, thousands of separate pictures on hundreds of feet of film being developed at once.

A negative, however, is of no use unless a positive or print of some kind is made from it. If shown through a stereopticon, for instance, a negative would make all the shadows on the screen appear lights, and vice versa. A positive, therefore, is made by running a fresh film, with the negative, through a machine very much like the moving-picture camera. The unexposed surface is behind that of the negative, and at the proper intervals the shutter is opened and the admitted light prints the image of the negative on the unexposed film, just as a lantern slide is made, in fact, or a print on sensitised paper. The positives are made by this machine at the rate of a score or so in a second. Of course, the positive is developed in the same manner as the negative.

Therefore, in order to show the people in the theatre the Suburban, five hundred feet of film was exposed, developed, fixed, and dried, and nearly ten thousand separate and complete pictures were produced, in the space of two hours and fifteen minutes, including the time occupied in taking the films to and from the track, factory, and theatre.

Originally, successive pictures of moving objects were taken for scientific purposes. A French scientist who was studying aerial navigation set up a number of cameras and took successive pictures of a bird's flight. Doctor Muybridge, of Philadelphia, photographed trotting horses with a camera of his own invention that made exposures in rapid succession, in order to learn the different positions of the legs of animals while in rapid motion.

A Frenchman also—M. Mach—photographed a plant of rapid growth twice a day from exactly the same position for fifty consecutive days. When the pictures were thrown on the screen in rapid order the plant seemed to grow visibly.

The moving pictures provide a most attractive entertainment, and it was this feature of the idea, undoubtedly, that furnished the incentive to inventors. The public is always willing to pay well for a good amusement.

The makers of the moving-picture films have photographic studios suitably lighted and fitted with all the necessary stage accessories (scenery, properties, etc.) where the little comedies shown on the screens of the theatres are acted for the benefit of the rapid-fire camera and its operators, who are often the only spectators. One of these studios in the heart of the city of New York is so brilliantly lighted by electricity that pictures may be taken at full speed, thirty to forty-five per second, at any time of day or night. Another company has an open-air gallery large enough for whole troops of cavalry to maneuver before the camera, or where the various evolutions of a working fire department may be photographed.

Of course, when the pictures are taken in a studio or place prepared for the work the photographic part is easy—the camera man sets up his machine and turns the crank while the performers do the rest. But some extra-ordinary pictures have been taken when the photographer had to seek his scene and work his machine under trying and even dangerous circumstances.

During the Boer War in South Africa two operators for the Biograph Company took their bulky machine (it weighed about eighteen hundred pounds) to the very firing-line and took pictures of battles between the British and the Burghers when they were exposed to the fire of both armies. On one occasion, in fact, the operator who was turning the mechanism—he sat on a bicycle frame, the sprocket of which was connected by a chain with the interior machinery—during a battle, was knocked from his place by the concussion of a shell that exploded nearby; nevertheless, the film was saved, and the same man rode on horseback nearly seventy-five miles across country to the nearest railroad point so that the precious photographic record might be sent to London and shown to waiting audiences there.

Pictures were taken by the kinetoscope showing an ascent of Mount Blanc, the operator of the camera necessarily making the perilous journey also; different stages of the ascent were taken, some of them far above the clouds. For this series of pictures a film eight hundred feet long was required, and 12,800 odd exposures or negatives were made.

Successive pictures have been taken at intervals during an ocean voyage to show the life aboard ship, the swing of the great seas, and the rolling and pitching of the steamer. The heave and swing of the steamer and the mountainous waves have been so realistically shown on the screen in the theatre that some squeamish spectators have been made almost seasick. It might be comforting to those who were made unhappy by the sight of the heaving seas to know that the operator who took one series of sea pictures, when lashed with his machine in the lookout place on the foremast of the steamer, suffered terribly from seasickness, and would have been glad enough to set his foot on solid ground; nevertheless, he stuck to his post and completed the series.



It was a biograph operator that was engaged in taking pictures of a fire department rushing to a fire. Several pieces of apparatus had passed—an engine, hook-and-ladder company, and the chief; the operator, with his (then) bulky apparatus, large camera, storage batteries, etc., stood right in the centre of the street, facing the stream of engines, hose-wagons, and fire-patrol men. In order to show the contrast, an old-time hand-pump engine, dragged by a dozen men and boys, came along at full speed down the street, and behind and to one side of them followed a two-horse hose-wagon, going like mad. The men running with the old-time engine, not realising how narrow the space was and unaware of the plunging horses behind, passed the biograph man on one side on the dead run. The driver of the rapidly approaching team saw that there was no room for him to pass on the other side of the camera man, and his horses were going too fast to stop in the space that remained. He had but an instant to decide between the dozen men and their antiquated machine and the moving-picture outfit. He chose the latter, and, with a warning shout to the photographer, bore straight down on the camera, which continued to do its work faithfully, taking dozens of pictures a second, recording even the strained, anxious expression on the face of the driver. The pole of the hose-wagon struck the camera-box squarely and knocked it into fragments, and the wheels passed quickly over the pieces, the photographer meanwhile escaping somehow. By some lucky chance the box holding the coiled exposed film came through the wreck unscathed.

When that series was shown on the screen in a theatre the audience saw the engine and hook-and-ladder in turn come nearer and nearer and then rush by, then the line of running men with the old engine, and then—and their flesh crept when they saw it—a team of plunging horses coming straight toward them at frightful speed. The driver's face could be seen between the horses' heads, distorted with effort and fear. Straight on the horses came, their nostrils distended, their great muscles straining, their fore hoofs striking out almost, it seemed, in the faces of the people in the front row of seats. People shrank back, some women shrieked, and when the plunging horses seemed almost on them, at the very climax of excitement, the screen was darkened and the picture blotted out. The camera taking the pictures had continued to work to the very instant it was struck and hurled to destruction.

In addition to the stereopticon and its attendant mechanism, which is only suitable when the pictures are to be shown to an audience, a machine has been invented for the use of an individual or a small group of people. In the mutoscope the positives or prints are made on long strips of heavy bromide paper, instead of films, and are generally enlarged; the strip is cut up after development and mounted on a cylinder, so they radiate like the spokes of a wheel, and are set in the same consecutive order in which they were taken. The thousands of cards bearing the pictures at the outer ends are placed in a box, so that when the wheel of pictures is turned, by means of a crank attached to the axle, a projection holds each card in turn before the lens through which the observer looks. The projection in the top of the box acts like the thumb turning the pages of a book. Each of the pictures is presented in such rapid succession that the object appears to move, just as the scenes thrown on the screen by a lantern show action.

The mutoscope widens the use of motion-photography infinitely. The United States Government will use it to illustrate the workings of many of its departments at the World's Fair at St. Louis: the life aboard war-ships, the handling of big guns, army maneuvers, the life-saving service, post-office workings, and, in fact, many branches of the government service will be explained pictorially by this means.

Agents for manufacturers of large machinery will be able to show to prospective purchasers pictures of their machines in actual operation. Living, moving portraits have been taken, and by means of a hand machine can be as easily examined as pictures through a stereoscope. It is quite within the bounds of possibility that circulating libraries of moving pictures will be established, and that every public school will have a projecting apparatus for the use of films, and a stereopticon or a mutoscope. In fact, a sort of circulating library already exists, films or mutoscope pictures being rented for a reasonable sum; and thus many of the most important of the world's happenings may be seen as they actually occurred.

Future generations will have histories illustrated with vivid motion pictures, as all the great events of the day, processions, celebrations, battles, great contests on sea and land are now recorded by the all-seeing eye of the motion-photographer's camera.



BRIDGE BUILDERS AND SOME OF THEIR ACHIEVEMENTS

In the old days when Rome was supreme a Caesar decreed that a bridge should be built to carry a military road across a valley, or ordered that great stone arches should be raised to conduct a stream of water to a city; and after great toil, and at the cost of the lives of unnumbered labourers, the work was done—so well done, in fact, that much of it is still standing, and some is still doing service.

In much the same regal way the managers of a railroad order a steel bridge flung across a chasm in the midst of a wilderness far from civilisation, or command that a new structure shall be substituted for an old one without disturbing traffic; and, lo and behold, it is done in a surprisingly short time. But the new bridges, in contrast to the old ones, are as spider webs compared to the overarching branches of a great tree. The old type, built of solid masonry, is massive, ponderous, while the new, slender, graceful, is built of steel.

One day a bridge-building company in Pennsylvania received the specifications giving the dimensions and particulars of a bridge that an English railway company wished to build in far-off Burma, above a great gorge more than eight hundred feet deep and about a half-mile wide. From the meagre description of the conditions and requirements, and from the measurements furnished by the railroad, the engineers of the American bridge company created a viaduct. Just as an author creates a story or a painter a picture, so these engineers built a bridge on paper, except that the work of the engineers' imagination had to be figured out mathematically, proved, and reproved. Not only was the soaring structure created out of bare facts and dry statistics, but the thickness of every bolt and the strain to be borne by every rod were predetermined accurately.

And when the plans of the great viaduct were completed the engineers knew the cost of every part, and felt so sure that the actual bridge in far-off Burma could be built for the estimated amount, that they put in a bid for the work that proved to be far below the price asked by English builders.

And so this company whose works are in Pennsylvania was awarded the contract for the Gokteik viaduct in Burma, half-way round the world from the factory.



In the midst of a wilderness, among an ancient people whose language and habits were utterly strange to most Americans, in a tropical country where modern machinery and appliances were practically unknown, a small band of men from the young republic contracted to build the greatest viaduct the world had ever seen. All the material, all the tools and machinery, were to be carried to the opposite side of the earth and dumped on the edge of the chasm. From the heaps of metal the small band of American workmen and engineers, aided by the native labourers, were to build the actual structure, strong and enduring, that was conceived by the engineers and reduced to working-plans in far-off Pennsylvania.

From ore dug out of the Pennsylvania mountains the steel was made and, piece by piece, the parts were rolled, riveted, or welded together so that every section was exactly according to the measurements laid out on the plan. As each part was finished it was marked to correspond with the plan and also to show its relation to its neighbour. It was like a gigantic puzzle. The parts were made to fit each other accurately, so that when the workmen in Burma came to put them together the tangle of beams and rods, of trusses and braces should be assembled into a perfect, orderly structure—each part in its place and each doing its share of the work.

With men trained to work with ropes and tackle collected from an Indian seaport, and native riveters gathered from another place, Mr. J.C. Turk, the engineer in charge, set to work with the American bridgemen and the constructing engineer to build a bridge out of the pieces of steel that lay in heaps along the brink of the gorge. First, the traveller, or derrick, shipped from America in sections, was put together, and its long arm extended from the end of the tracks on which it ran over the abyss.

From above the great steel beams were lowered to the masonry foundations of the first tower and securely bolted to them, and so, piece by piece, the steel girders were suspended in space and swung this way and that until each was exactly in its proper position and then riveted permanently. The great valley resounded with the blows of hammers on red-hot metal, and the clangour of steel on steel broke the silence of the tropic wilderness. The towers rose up higher and higher, until the tops were level with the rim of the valley, and as they were completed the horizontal girders were built on them, the rails laid, and the traveller pushed forward until its arm swung over the foundation of the next tower.

And so over the deep valley the slender structure gradually won its way, supporting itself on its own web as it crawled along like a spider. Indeed, so tall were its towers and so slender its steel cords and beams that from below it appeared as fragile as a spider's web, and the men, poised on the end of swinging beams or standing on narrow platforms hundreds of feet in air, looked not unlike the flies caught in the web.

The towers, however, were designed to sustain a heavy train and locomotive and to withstand the terrific wind of the monsoon. The pressure of such a wind on a 320-foot tower is tremendous. The bridge was completed within the specified time and bore without flinching all the severe tests to which it was put. Heavy trains—much heavier than would ordinarily be run over the viaduct—steamed slowly across the great steel trestle while the railroad engineers examined with utmost care every section that would be likely to show weakness. But the designers had planned well, the steel-workers had done their full duty, and the American bridgemen had seen to it that every rivet was properly headed and every bolt screwed tight—and no fault could be found.

The bridge engineer's work is very diversified, since no two bridges are alike. At one time he might be ordered to span a stream in the midst of a populous country where every aid is at hand, and his next commission might be the building of a difficult bridge in a foreign wilderness far beyond the edge of civilisation.

Bridge-building is really divided into four parts, and each part requires a different kind of knowledge and experience.

First, the designer has to have the imagination to see the bridge as it will be when it is completed, and then he must be able to lay it out on paper section by section, estimating the size of the parts necessary for the stress they will have to bear, the weight of the load they will have to carry, the effect of the wind, the contraction and expansion of cold and heat, and vibration; all these things must be thought of and considered in planning every part and determining the size of each. Also he must know what kind of material to use that is best fitted to stand each strain, whether to use steel that is rigid or that which is so flexible that it can be tied in a knot. On the designer depends the price asked for the work, and so it is his business to invent, for each bridge is a separate problem in invention, a bridge that will carry the required weight with the least expenditure of material and labour and at the same time be strong enough to carry very much greater loads than it is ever likely to be called upon to sustain. The designer is often the constructor as well, and he is always a man of great practical experience. He has in his time stepped out on a foot-wide girder over a rushing stream, directing his men, and he has floundered in the mud of a river bottom in a caisson far below the surface of the stream, while the compressed air kept the ooze from flowing in and drowning him and his workmen.

The second operation of making the pieces that go into the structure is simply the following out of the clearly drawn plans furnished by the designing engineers. Different grades of steel and iron are moulded or forged into shape and riveted together, each part being made the exact size and shape required, even the position of the holes through which the bolts or rivets are to go that are to secure it to the neighbouring section being marked on the plan.

The foundations for bridges are not always put down by the builders of the bridge proper; that is a work by itself and requires special experience. On the strength and permanency of the foundation depends the life of the bridge. While the foundries and steel mills are making the metal-work the foundations are being laid. If the bridge is to cross a valley, or carry the roadway on the level across a depression, the placing of the foundations is a simple matter of digging or blasting out a big hole and laying courses of masonry; but if a pier is to be built in water, or the land on which the towers are to stand is unstable, then the problem is much more difficult.

For bridges like those that connect New York and Brooklyn, the towers of which rest on bed-rock below the river's bottom, caissons are sunk and the massive masonry is built upon them. If you take a glass and sink it in water, bottom up, carefully, so that the air will not escape, it will be noticed that the water enters the glass but a little way: the air prevents the water from filling the glass. The caisson works on the same principle, except that the air in the great boxlike chamber is highly compressed by powerful pumps and keeps the water and river ooze out altogether.

The caissons of the third bridge across the East River were as big as a good-sized house—about one hundred feet long and eighty feet wide. It took five large tugs more than two days to get one of them in its proper place. Anchored in its exact position, it was slowly sunk by building the masonry of the tower upon it, and when the lower edges of the great box rested on the bottom of the river men were sent down through an air-lock which worked a good deal like the lock of a canal. The men, two or three at a time, entered a small round chamber built of steel which was fitted with two air-tight doors at the top and bottom; when they were inside the air-lock, the upper door was closed and clamped tight, just as the gates leading from the lower level of a canal are closed after the boat is in the lock; then very gradually the air in the compartment is compressed by an air-compressor until the pressure in the air-lock is the same as that in the caisson chamber, when the lower door opened and allowed the men to enter the great dim room. Imagine a room eighty by one hundred feet, low and criss-crossed by massive timber braces, resting on the black, slimy mud of the river bottom; electric lights shine dimly, showing the half-naked workmen toiling with tremendous energy by reason of the extra quantity of oxygen in the compressed air. The workmen dug the earth and mud from under the iron-shod edges of the caisson, and the weight of the masonry being continually added to above sunk the great box lower and lower. From time to time the earth was mixed with water and sucked to the surface by a great pump. With hundreds of tons of masonry above, and the watery mud of the river on all sides far below the keels of the vessels that passed to and fro all about, the men worked under a pressure that was two or three times as great as the fifteen pounds to the square inch that every one is accustomed to above ground. If the pressure relaxed for a moment the lives of the men would be snuffed out instantly—drowned by the inrushing waters; if the excavation was not even all around, the balance of the top-heavy structure would be lost, the men killed, and the work destroyed entirely. But so carefully is this sort of work done that such an accident rarely occurs, and the caissons are sunk till they rest on bed-rock or permanent, solid ground, far below the scouring effect of currents and tides. Then the air-chamber is filled with concrete and left to support the great towers that pierce the sky above the waters.



The pneumatic tube, which is practically a steel caisson on a small scale operated in the same way, is often used for small towers, and many of the steel sky-scrapers of the cities are built on foundations of this sort when the ground is unstable.

Foundations of wooden and iron piles, driven deep in the ground below the river bottom, are perhaps the most common in use. The piles are sawed off below the surface of the water and a platform built upon them, which in turn serves as the foundation for the masonry.

The great Eads Bridge, which was built across the Mississippi at St. Louis, is supported by towers the foundations of which are sunk 107 feet below the ordinary level of the water; at this depth the men working in the caissons were subjected to a pressure of nearly fifty pounds to the square inch, almost equal to that used to run some steam-engines.

The bridge across the Hudson at Poughkeepsie was built on a crib or caisson open at the top and sunk by means of a dredge operated from above taking out the material from the inside. The wonder of this is hard to realise unless it is remembered that the steel hands of the dredge were worked entirely from above, and the steel rope sinews reached down below the surface more than one hundred feet sometimes; yet so cleverly was the work managed that the excavation was perfect all around, and the crib sank absolutely straight and square.

It is the fourth department of bridge-building that requires the greatest amount not only of knowledge but of resourcefulness. In the final process of erection conditions are likely to arise that were not considered when the plans were drawn.

The chief engineer in charge of the erection of a bridge far from civilisation is a little king, for it is necessary for him to have the power of an absolute monarch over his army of workmen, which is often composed of many different races.

With so many thousand tons of steel and stone dumped on the ground at the bridge site, with a small force of expert workmen and a greater number of unskilled labourers, in spite of bad weather, floods, or fearful heat, the constructing engineer is expected to finish the work within the specified time, and yet it must withstand the most exacting tests.

In the heart of Africa, five hundred miles from the coast and the source of supplies, an American engineer, aided by twenty-one American bridgemen, built twenty-seven viaducts from 128 to 888 feet long within a year.

The work was done in half the time and at half the cost demanded by the English bidders. Mr. Lueder, the chief engineer, tells, in his account of the work, of shooting lions from the car windows of the temporary railroad, and of seeing ostriches try to keep pace with the locomotive, but he said little of his difficulties with unskilled workmen, foreign customs, and almost unspeakable languages. The bridge engineer the world over is a man who accomplishes things, and who, furthermore, talks little of his achievements.

Though the work of the bridge builders within easy reach of the steel mills and large cities is less unusual, it is none the less adventurous.

In 1897, a steel arch bridge was completed that was built around the old suspension bridge spanning the Niagara River over the Whirlpool Rapids. The old suspension bridge had been in continuous service since 1855 and had outlived its usefulness. It was decided to build a new one on the same spot, and yet the traffic in the meantime must not be disturbed in the least. It would seem that this was impossible, but the engineers intrusted with the work undertook it with perfect confidence. To any one who has seen the rushing, roaring, foaming waters of unknown depth that race so fast from the spray-veiled falls that they are heaped up in the middle, the mere thought of men handling huge girders of steel above the torrent, and of standing on frail swinging platforms two hundred or more feet above the rapids, causes chills to run down the spine; yet the work was undertaken without the slightest doubt of its successful fulfilment.

It was manifestly impossible to support the new structure from below, and the old bridge was carrying about all it could stand, so it was necessary to build the new arch, without support from underneath, over the foaming water of the Niagara rapids two hundred feet below. Steel towers were built on either side of the gorge, and on them was laid the platform of the bridge from the towers nearest to the water around and under the old structure. The upper works were carried to the solid ground on a level with the rim of the gorge and there securely anchored with steel rods and chains held in masonry. Then from either side the arch was built plate by plate from above, the heavy sheets of steel being handled from a traveller or derrick that was pushed out farther and farther over the stream as fast as the upper platform was completed. The great mass of metal on both sides of the Niagara hung over the stream, and was only held from toppling over by the rods and chains solidly anchored on shore. Gradually the two ends of the uncompleted arch approached each other, the amount of work on each part being exactly equal, until but a small space was left between. The work was so carefully planned and exactly executed that the two completed halves of the arch did not meet, but when all was in readiness the chains on each side, bearing as they did the weight of more than 1,000,000 pounds, were lengthened just enough, and the two ends came together, clasping hands over the great gorge. Soon the tracks were laid, and the new bridge took up the work of the old, and then, piece by piece, the old suspension bridge, the first of its kind, was demolished and taken away.

Over the Niagara gorge also was built one of the first cantilever bridges ever constructed. To uphold it, two towers were built close to the water's edge on either side, and then from the towers to the shores, on a level with the upper plateau, the steel fabric, composed of slender rods and beams braced to stand the great weight it would have to carry, was built on false work and secured to solid anchorages on shore. Then on this, over tracks laid for the purpose, a crane was run (the same process being carried out on both sides of the river simultaneously), and so the span was built over the water 239 feet above the seething stream, the shore ends balancing the outer sections until the two arms met and were joined exactly in the middle. This bridge required but eight months to build, and was finished in 1883. From the car windows hardly any part of the slender structure can be seen, and the train seems to be held over the foaming torrent by some invisible support, yet hundreds of trains have passed over it, the winds of many storms have torn at its members, heat and cold have tried by expansion and contraction to rend it apart, yet the bridge is as strong as ever.

Sometimes bridges are built a span or section at a time and placed on great barges, raised to just their proper height, and floated down to the piers and there secured.

A railroad bridge across the Schuylkill at Philadelphia was judged inadequate for the work it had to do, and it was deemed necessary to replace it with a new one. The towers it rested upon, therefore, were widened, and another, stronger bridge was built alongside, the new one put upon rollers as was the old, and then between trains the old structure was pushed to one side, still resting on the widened piers, and the new bridge was pushed into its place, the whole operation occupying less than three minutes. The new replaced the old between the passing of trains that run at four or five-minute intervals. The Eads Bridge, which crosses the Mississippi at St. Louis, was built on a novel plan. Its deep foundations have already been mentioned. The great "Father of Waters" is notoriously fickle; its channel is continually changing, the current is swift, and the frequent floods fill up and scour out new channels constantly. It was necessary, therefore, in order to span the great stream, to place as few towers as possible and build entirely from above or from the towers themselves. It was a bold idea, and many predicted its failure, but Captain Eads, the great engineer, had the courage of his convictions and carried out his plans successfully. From each tower a steel arch was started on each side, built of steel tubes braced securely; the building on each side of every tower was carried on simultaneously, one side of every arch balancing the weight on the other side. Each section was like a gigantic seesaw, the tower acting as the centre support; the ends, of course, not swinging up and down. Gradually the two sections of every arch approached each other until they met over the turbid water and were permanently connected. With the completion of the three arches, built entirely from the piers supporting them, the great stream was spanned. The Eads Bridge was practically a double series of cantilevers balancing on the towers. Three arches were built, the longest being 520 feet long and the two shorter ones 502 feet each.

Every situation that confronts the bridge builder requires different handling; at one time he may be called upon to construct a bridge alongside of a narrow, rocky cleft over a rushing stream like the Royal Gorge, Colorado, where the track is hung from two great beams stretched across the chasm, or he may be required to design and construct a viaduct like that gossamer structure three hundred and five feet high and nearly a half-mile long across the Kinzua Creek, in Pennsylvania. Problems which have nothing to do with mechanics often try his courage and tax his resources, and many difficulties though apparently trivial, develop into serious troubles. The caste of the different native gangs who worked on the twenty-seven viaducts built in Central Africa is a case in point: each group belonging to the same caste had to be provided with its own quarters, cooking utensils, and camp furniture, and dire were the consequences of a mix-up during one of the frequent moves made by the whole party.



And so the work of a bridge builder, whether it is creating out of a mere jumble of facts and figures a giant structure, the shaping of glowing metal to exact measurements, the delving in the slime under water for firm foundations, or the throwing of webs of steel across yawning chasms or over roaring streams, is never monotonous, is often adventurous, and in many, many instances is a great civilising influence.



SUBMARINES IN WAR AND PEACE

During the early part of the Spanish-American war a fleet of vessels patrolled the Atlantic coast from Florida to Maine. The Spanish Admiral Cervera had left the home waters with his fleet of cruisers and torpedo-boats and no one knew where they were. The lookouts on all the vessels were ordered to keep a sharp watch for strange ships, and especially for those having a warlike appearance. All the newspapers and letters received on board the different cruisers of the patrol fleet told of the anxiety felt in the coast towns and of the fear that the Spanish ships would appear suddenly and begin a bombardment. To add to the excitement and expectation, especially of the green crews, the men were frequently called out of their comfortable hammocks in the middle of the night, and sent to their stations at guns and ammunition magazines, just as if a battle was imminent; all this was for the purpose of familiarising the crews with their duties under war conditions, though no enlisted man knew whether he was called to quarters to fight or for drill.

These were the conditions, then, when one bright Sunday the crew of an auxiliary cruiser were very busy cleaning ship—a very thorough and absorbing business. While the men were in the thick of the scrubbing, one of the crew stood up to straighten his back, and looked out through an open port in the vessel's side. As he looked he caught a glimpse of a low, black craft, hardly five hundred yards off, coming straight for the cruiser. The water foamed at her bows and the black smoke poured out of her funnels, streaking behind her a long, sinister cloud. It was one of those venomous little torpedo-boats, and she was apparently rushing in at top speed to get within easy range of the large warship.

"A torpedo-boat is headed straight for us," cried the man at the port, and at the same moment came the call for general quarters.

As the men ran to their stations the word was passed from one to the other, "A Spanish torpedo-boat is headed for us."

With haste born of desperation the crew worked to get ready for action, and when all was ready, each man in his place, guns loaded, firing lanyards in hand, gun-trainers at the wheels, all was still—no command to fire was given.

From the signal-boys to the firemen in the stokehole—for news travels fast aboard ship—all were expecting the muffled report and the rending, tearing explosion of a torpedo under the ship's bottom. The terrible power of the torpedo was known to all, and the dread that filled the hearts of that waiting crew could not be put into words.

Of course it was a false alarm. The torpedo-boat flew the Stars and Stripes, but the heavy smoke concealed it, and the officers, perceiving the opportunities for testing the men, let it be believed that a boat belonging to the enemy was bearing down on them.

The crews of vessels engaged in future wars will have, not only swifter, surer torpedo-boats to menace them, but even more dreadful foes.

The conning towers of the submarines show but a foot or two above the surface—a sinister black spot on the water, like the dorsal fin of a shark, that suggests but does not reveal the cruel power below; for an instant the knob lingers above the surface while the steersman gets his bearings, and then it sinks in a swirling eddy, leaving no mark showing in what direction it has travelled. Then the crew of the exposed warship wait and wonder with a sickening cold fear in their hearts how soon the crash will come, and pray that the deadly submarine torpedo will miss its mark.

Submarine torpedo-boats are actual, practical working vessels to-day, and already they have to be considered in the naval plans for attack and defense.

Though the importance of submarines in warfare, and especially as a weapon of defense, is beginning to be thoroughly recognised, it took a long time to arouse the interest of naval men and the public generally sufficient to give the inventors the support they needed.

Americans once had within their grasp the means to blow some of their enemies' ships out of the water, but they did not realise it, as will be shown in the following, and for a hundred years the progress in this direction was hindered.

It was during the American Revolution that a man went below the surface of the waters of New York Harbour in a submarine boat just big enough to hold him, and in the darkness and gloom of the under-water world propelled his turtle-like craft toward the British ships anchored in mid-stream. On the outside shell of the craft rested a magazine with a heavy charge of gunpowder which the submarine navigator intended to screw fast to the bottom of a fifty-gun British man-of-war, and which was to be exploded by a time-fuse after he had got well out of harm's way.

Slowly and with infinite labour this first submarine navigator worked his way through the water in the first successful under-water boat, the crank-handle of the propelling screw in front of him, the helm at his side, and the crank-handle of the screw that raised or lowered the craft just above and in front. No other man had made a like voyage; he had little experience to guide him, and he lacked the confidence that a well-tried device assures; he was alone in a tiny vessel with but half an hour's supply of air, a great box of gunpowder over him, and a hostile fleet all around. It was a perilous position and he felt it. With his head in the little conning tower he was able to get a glimpse of the ship he was bent on destroying, as from time to time he raised his little craft to get his bearings. At last he reached his all-unsuspecting quarry and, sinking under the keel, tried to attach the torpedo. There in the darkness of the depths of North River this unnamed hero, in the first practical submarine boat, worked to make the first torpedo fast to the bottom of the enemy's ship, but a little iron plate or bolt holding the rudder in place made all the difference between a failure that few people ever heard of and a great achievement that would have made the inventor of the boat, David Bushnell, famous everywhere, and the navigator a great hero. The little iron plate, however, prevented the screw from taking hold, the tide carried the submarine past, and the chance was lost.

David Bushnell was too far ahead of his time, his invention was not appreciated, and the failure of his first attempt prevented him from getting the support he needed to demonstrate the usefulness of his under-water craft. The piece of iron in the keel of the British warship probably put back development of submarine boats many years, for Bushnell's boat contained many of the principles upon which the successful under-water craft of the present time are built.

One hundred and twenty-five years after the subsurface voyage described above, a steel boat, built like a whale but with a prow coming to a point, manned by a crew of six, travelling at an average rate of eight knots an hour, armed with five Whitehead torpedoes, and designed and built by Americans, passed directly over the spot where the first submarine boat attacked the British fleet.

The Holland boat Fulton had already travelled the length of Long Island Sound, diving at intervals, before reaching New York, and was on her way to the Delaware Capes.

She was the invention of John P. Holland, and the result of twenty-five years of experimenting, nine experimental boats having been built before this persistent and courageous inventor produced a craft that came up to his ideals. The cruise of the Fulton was like a march of triumph, and proved beyond a doubt that the Holland submarines were practical, sea-going craft.

At the eastern end of Long Island the captain and crew, six men in all, one by one entered the Fulton through the round hatch in the conning tower that projected about two feet above the back of the fish-like vessel. Each man had his own particular place aboard and definite duties to perform, so there was no need to move about much, nor was there much room left by the gasoline motor, the electric motor, storage batteries, air-compressor, and air ballast and gasoline tanks, and the Whitehead torpedoes. The captain stood up inside of the conning tower, with his eyes on a level with the little thick glass windows, and in front of him was the wheel connecting with the rudder that steered the craft right and left; almost at his feet was stationed the man who controlled the diving-rudders; farther aft was the engineer, all ready for the word to start his motor; another man controlled the ballast tanks, and another watched the electric motor and batteries.

With a clang the lid-like hatch to the conning tower was closed and clamped fast in its rubber setting, the gasoline engine began its rapid phut-phut, and the submarine boat began its long journey down Long Island Sound. The boat started in with her deck awash—that is, with two or three feet freeboard or of deck above the water-line. In this condition she could travel as long as her supply of gasoline held out—her tanks holding enough to drive her 560 knots at the speed of six knots an hour, when in the semi-awash condition; the lower she sank the greater the surface exposed to the friction of the water and the greater power expended to attain a given speed.

As the vessel jogged along, with a good part of her deck showing above the waves, her air ventilators were open and the burnt gas of the engine was exhausted right out into the open; the air was as pure as in the cabin of an ordinary ship. Besides the work of propelling the boat, the engine being geared to the electric motor made it revolve, so turning it into a dynamo that created electricity and filled up the storage batteries.



From time to time, as this whale-like ship plowed the waters of the Sound, a big wave would flow entirely over her, and the captain would be looking right into the foaming crest. The boat was built for under-water going, so little daylight penetrated the interior through the few small deadlights, or round, heavy glass windows, but electric incandescent bulbs fed by current from the storage batteries lit the interior brilliantly.

The boat had not proceeded far when the captain ordered the crew to prepare to dive, and immediately the engine was shut down and the clutch connecting its shaft with the electric apparatus thrown off and another connecting the electric motor with the propeller thrown in; a switch was then turned and the current from the storage batteries set the motor and propeller spinning. While this was being done another man was letting water into her ballast tanks to reduce her buoyancy. When all but the conning tower was submerged the captain looked at the compass to see how she was heading, noted that no vessels were near enough to make a submarine collision likely, and gave the word to the man at his feet to dive twenty feet. Then a strange thing happened. The diving-helmsman gave a twist to the wheel that connected with the horizontal rudders aft of the propeller, and immediately the boat slanted downward at an angle of ten degrees; the water rose about the conning tower until the little windows were level with the surface, and then they were covered, and the captain looked into solid water that was still turned yellowish-green by the light of the sun; then swiftly descending, he saw but the faintest gleam of green light coming through twenty feet of water. The Fulton, with six men in her, was speeding along at five knots an hour twenty feet below the shining waters of the Sound.

The diving-helmsman kept his eye on a gauge in front of him that measured the pressure of water at the varying depths, but the dial was so marked that it told him just how many feet the Fulton was below the surface. Another device showed whether the boat was on an even keel or, if not exactly, how many degrees she slanted up or down.

With twenty feet of salt water above her and as much below, this mechanical whale cruised along with her human freight as comfortable as they would have been in the same space ashore. The vessel contained sufficient air to last them several hours, and when it became vitiated there were always the tanks of compressed air ready to be drawn upon.

Except for the hum of the motor and the slight clank of the steering-gear, all was silent; none of the noises of the outer world penetrated the watery depths; neither the slap of the waves, the whir of the breeze, the hiss of steam, nor rattle of rigging accompanied the progress of this submarine craft. As silently as a fish, as far as the outer world was concerned, the Fulton crept through the submarine darkness. If an enemy's ship was near it would be an easy thing to discharge one of the five Whitehead torpedoes she carried and get out of harm's way before it struck the bottom of the ship and exploded.

In the tube which opened at the very tip end of the nose of the craft lay a Whitehead (or automobile) torpedo, which when properly set and ejected by compressed air propelled itself at a predetermined depth at a speed of thirty knots an hour until it struck the object it was aimed at or its compressed air power gave out.

The seven Holland boats built for the United States Navy, of which the Fulton is a prototype, carry five of these torpedoes, one in the tube and two on either side of the hold, and each boat is also provided with one compensating tank for each torpedo, so that when one or all are fired their weight may be compensated by filling the tanks with water so that the trim of the vessel will be kept the same and her stability retained.

The Fulton, however, was bent on a peaceful errand, and carried dummy torpedoes instead of the deadly engines of destruction that the man-o'-war's man dreads.

"Dive thirty," ordered the captain, at the same time giving his wheel a twist to direct the vessel's course according to the pointing finger of the compass.

"Dive thirty, sir," repeated the steersman below, and with a slight twist of his gear the horizontal rudders turned and the submarine inclined downward; the level-indicator showed a slight slant and the depth-gauge hand turned slowly round—twenty-two, twenty-five, twenty-eight, then thirty feet, when the helmsman turned his wheel back a little and the vessel forged ahead on a level keel.

At thirty feet below the surface the little craft, built like a cigar on purpose to stand a tremendous squeeze, was subjected to a pressure of 2,160 pounds to the square foot. To realise this pressure it will be necessary to think of a slab of iron a foot square and weighing 2,160 pounds pressing on every foot of the outer surface of the craft. Of course, the squeeze is exerted on all sides of the submarine boats when fully submerged, just as every one is subjected to an atmospheric pressure of fifteen pounds to the square inch on every inch of his body.

The Fulton and other submarine boats are so strongly built and thoroughly braced that they could stand an even greater pressure without damage.

When the commander of the Fulton ordered his vessel to the surface, the diving-steersman simply reversed his rudders so that they turned upward, and the propeller, aided by the natural buoyancy of the boat, simply pushed her to the surface. The Holland boats have a reserve buoyancy, so that if anything should happen to the machinery they would rise unaided to the surface.

Compressed air was turned into the ballast tanks, the water forced out so that the boat's buoyancy was increased, and she floated in a semi-awash, or light, condition. The engineer turned off the current from the storage batteries, threw off the motor from the propeller shaft, and connected the gasoline engine, started it up, and inside of five minutes from the time the Fulton was navigating the waters of the Sound at a depth of thirty feet she was sailing along on the surface like any other gasoline craft.

And so the ninety-mile journey down Long Island Sound, partly under water, partly on the surface, to New York, was completed. The greater voyage to the Delaware Capes followed, and at all times the little sixty-three-foot boat that was but eleven feet in diameter at her greatest girth carried her crew and equipment with perfect safety and without the least inconvenience.

Such a vessel, small in size but great in destructive power, is a force to be reckoned with by the most powerful battle-ship. No defense has yet been devised that will ward off the deadly sting of the submarine's torpedo, delivered as it is from beneath, out of the sight and hearing of the doomed ships' crews, and exploded against a portion of the hull that cannot be adequately protected by armour.

Though the conning-dome of a submarine presents a very small target, its appearance above water shows her position and gives warning of her approach. To avoid this tell-tale an instrument called a periscope has been invented, which looks like a bottle on the end of a tube; this has lenses and mirrors that reflect into the interior of the submarine whatever shows above water. The bottle part projects above, while the tube penetrates the interior.



The very unexpectedness of the submarine's attack, the mere knowledge that they are in the vicinity of a fleet and may launch their deadly missiles at any time, is enough to break down the nerves of the strongest and eventually throw into a panic the bravest crew.

That the crews of the war-ships will have to undergo the strain of submarine attack in the next naval war is almost sure. All the great nations of the world have built fleets of submarines or are preparing to do so.

In the development of under-water fighting-craft France leads, as she has the largest fleet and was the first to encourage the designing and building of them. But it was David Bushnell that invented and built the first practical working submarine boat, and in point of efficiency and practical working under service conditions in actual readiness for hostile action the American boats excel to-day.



A PEACEFUL SUBMARINE

Under the green sea, in the total darkness of the great depths and the yellowish-green of the shallows of the oceans, with the seaweeds waving their fronds about their barnacle-encrusted timbers and the creatures of the deep playing in and about the decks and rotted rigging, lie hundreds of wrecks. Many a splendid ship with a valuable cargo has gone down off a dangerous coast; many a hoard of gold or silver, gathered with infinite pains from the far corners of the earth, lies intact in decaying strong boxes on the bottom of the sea.

To recover the treasures of the deep, expeditions have been organised, ships have sailed, divers have descended, and crews have braved great dangers. Many great wrecking companies have been formed which accomplish wonders in the saving of wrecked vessels and cargoes. But in certain places all the time and at others part of the time, wreckers have had to leave valuable wrecks a prey to the merciless sea because the ocean is too angry and the waves too high to permit of the safe handling of the air-hose and life-line of the divers who are depended upon to do all the under-water work, rigging of hoisting-tackle, placing of buoys, etc. Indeed, it is often impossible for a vessel to stay in one place long enough to accomplish anything, or, in fact, to venture to the spot at all.

It was an American boy who, after reading Jules Verne's "Twenty Thousand Leagues Under the Sea," said to himself, "Why not?" and from that time set out to put into practice what the French writer had imagined.