the ratio is inexorable. The elimination of a single ton from that irreducible minimum will mean that some fighting man must go without the requisite clothing, food, medical supplies, or munitions of war that would make him 100 per cent effective against the Hun.

Nor is this ratio of three tons to one man a liberal estimate. At the beginning of the conflict the number of ship tons required for each man was as high as five or six-about the same ratio which Great Britain found necessary to keep her army of occupation on the arid Gallipoli Peninsula, where water as well as food and munitions had to be brought by ship. It is only through the genius of organization, of rapidly developing and developed efficiency in the handling of cargoes, both in our own loading ports and in French ports of discharge, and in the hurry-hurry-hurry impulse which actuates the master and crew of every ship at sea flying the American flag, that the tonnage per man has been reduced.

This ratio applies only to our men on the western front. If any considerable number of troops is dispatched to Russia or Siberia, the ratio of ship tonnage per man unit of those forces will rise to six, for the voyage from San Francisco to Vladivostok is twice as long, and two ships making eight round trips a year can carry no larger quantity of supplies than one ship making sixteen round-trip voyages. Of course, much of the foodstuffs required by our Siberian forces would be supplied from Australia, from the Philip pines, and in some measure from Hawaii. Japan will be more or less busy keeping her own troops supplied, especially as she has already greatly depleted her shipping resources by charter to the United States.

SHIPS FOR THOSE AT HOME

When we have supplied the vital needs of our uniformed forces, there are the people at home to be provided for the great army of a hundred million men, women, and children engaged in the essential industries, occupations, and pursuits of a nation at war. They, as well as the soldiers, must be supplied with the raw products of many climes-sugar and coffee and rubber from the tropics; nitrates, pyrites, manganese, sulphur, and

other substances which go into the manufacture of war's engines of destruction; hides and wool, hemp and sisal, oil, meats and wheat to supplement our own stocks depleted by export to our Allies. All these and a countless number of other articles of food, clothing, and industry must come to us in ships. Ships! Ships! SHIPS!

How, then, is the United States Shipping Board, together with its great auxiliary agencies the Emergency Fleet Corporation, the Merchant Marine Recruiting Service, and the Port and Harbor Facilities Commission-supplying the nation's needs in the hour of its extremity?

The undertaking, beginning a little more than a year ago in abortive effort, misdirected energy, and chaotic confusion, which seems to be a natural law when any really great program is launched, has gradually evolved into order. The horizon of the immediate future is aglow with the promise of notable achievement.

THE INTRICACY OF SHIPBUILDING

In view of the speed which at last is being attained in the quantity production of ships, it is an excusable error on the part of the layman to assume that the construction of sea-going craft is a comparatively simple undertaking. As a matter of fact, most of us, when the imperative need for a vast American merchant fleet was suddenly realized eighteen months ago, looked upon ship-building with about the same nonchalance as the would-be airplane manufacturer who, in in the early days of the war, sought a contract from the government, declaring that he needed no special equipment for the undertaking, as he could "whittle a flying machine out of a piece of timber with a drawing-knife." Many people still imagine that a ship of wood, steel, or concrete is little more than a glorified row-boat.

In reality, the making of a ship is one of the most intricate achievements of industrial science, requiring the greatest nicety of calculation, workmanship, and correlation of parts. To cite a typical instance: So delicate must be the adjustment of machinery to hull that the shaft line (the location of the shaft which

transmits the power from the engine to the propeller) must be run (its position fixed). between II o'clock in the morning and 2 o'clock in the afternoon; otherwise the expansion of the metal caused by the heat of the sun's rays shining on one side of the vessel more than the other would deflect the line from the correct position, resulting in disaster to the machinery on the trial trip.

THE FABRICATED SHIP

The widely heralded fabricated steel ship has been the source of much popular confusion. It is generally assumed that the steel plates are cut to a pattern by the hundreds, like the parts of ready-made clothing. After a fashion, this is true, for scores of steel mills and machine shops and 1,000 auxiliary plants, scattered throughout the country and employing a million men, are manufacturing the parts which go to make up our standardized fabricated steel ships, including their engines and boilers. But this does not mean that the thousands of parts which go to make up each vessel can be transported to the seacoast, fitted to pattern like a jigsaw puzzle, pinned together with a few rivets, and pushed out into deep water, a completed cargo-carrier.

The intricacy of "putting together" a fabricated steel ship cannot be more forcefully suggested than to review the groups of men employed in the undertaking.

The erectors and their helpers, with the aid of steam cranes, swing the massive keel, plates, and beams in place. The riveters, with their gangs-the men who heat the rivets to the exact temperature required, the men who pass these rivets from the forges to the riveters lying prone upon their backs between the inner and outer "skin" of the ship, or perched high upon a scaffold at bow or stern, and the "buckers-up" (those who with hammer or counter pneumatic machine press down upon and brad the glowing steel pins which the riveters drive into place with their rivet-guns, striking more than a thousand 95-pound blows to the minute)-bind the plates together. It is the riveter's responsibility if the hull is not watertight or if his rivets are unable to resist the constant buffet of waves and

the throb of mighty engines urging the laden craft through heavy seas.

The task of the drillers and reamers is to alter the holes in the plates when they fail to match. Even the tailor-made suit needs a touch here and a stitch there at the first try-on, so it is not to be wondered at that the parts of a steel ship. made in many sections of the country, out of material which is seldom uniform, and under varying conditions of temperature, do not always fit. Where the holes are uneven they are made perfectly cylindrical by reaming, in order that the rivets may completely fill the space and thus avoid both a dangerous play of parts and subsequent leakage.

With both hand and pneumatic tools, the busy chippers trim off and smooth the edges of plates and castings, and when this work is done the calkers turn their attention to the edges of plates, angles, and rivet heads. Water must be kept out not only because of the immediate danger of ruining the cargo and sinking the ship, but also to avoid the insidious danger of small leaks that corrode the metal and in time cause serious structural weakness.

When the metal workers have completed their tasks the shipwrights install the wood decks, the wood foundations for capstans, winches, guns, and other parts. Theirs is the responsibility also for wooden masts, cargo booms and spars, and for launching ways. To joiners is intrusted the interior woodwork and state-room fittings.

Shrouds, stays, lifts, bracings for masts and funnels, life-lines, and all other wire and hemp rope rigging are installed by the "human flies" of the shipbuilding professio.-the riggers.

Besides these experts employed on the ships themselves, there is a hurrying group of machine shop and foundry men sheet-metal workers, plumbers, machinists, blacksmiths, drop forgers, electricians, and acetylene burners.

THE ARISTOCRATS OF LABOR

The coppersmiths deserve a paragraph to themselves, for they are among the aristocracy, the "400" of labor. Their number in America has been variously estimated at from 1,200 to 1,800. At the