compares poorly, he is informed that the school children of the community have been instructed to tell their parents which stores are kept free from flies. The public opinion thus brought to bear upon the merchant has worked wonders.

And here are the wonders: In an investigation of five hundred eleven grocery stores, confectioneries, meat stores, restaurants, and milk depots, no flies whatever were found in sixty per cent of the stores; less than three flies each were found in thirty-six per cent; and in only four per cent were flies at all numerous. In an inspection of the great city market where the acres of displayed provisions formerly attracted vast myriads of pests, only two flies were found!

When the campaign lagged a bit this year for want of funds and a contingent of insects crept back into the ancestral fly haunts, public opinion immediately

arose and demanded the redoubling of the movement. Clevelanders had been so well educated to detest flies that the fly campaign had become not a mere hygienic fad but a public necessity. So it is planned to continue the work apace, and to continue continuing it, until the word "house fly" becomes obsolete among Clevelanders. Cleveland is not yet absolutely a "flyless city" but it is approaching that goal more rapidly than any other great American city.

It seems quite possible that within this generation we shall witness the decline and fall of one of man's most deadly enemies-the "fly". With its elimination, whenever it comes, the specters of typhoid, cholera infantum, dysentery, tuberculosis, spinal meningitis, and many other diseases of which it has long been the chief distributor, will lose much of their terror.

T

HE "flying - fish torpedo" might more properly be be termed a combination of two inventions already familiarthe flying machine, and the automobile torpedo. Rear Admirai Bradley A. Fiske, the inventor, suggests that the torpedo of the Whitehead submarine type be carried by the aeroplane and launched by the aviator against the ship which may be picked out as a target.

There can be no question of the fact that the submarine torpedo is the most deadly instrument of destruction thus far contrived by human ingenuity. Most of us felt a thrill of horror when three of these little mechanical devil

fish, costing about eight thousand dollars apiece, within twenty minutes cank the British armored cruisers Agincourt, Aboukir, and Cressy in the North Sea, incidentally drowning more than twelve hundred men. Great battleships have been sunk since by submarines, without eliciting the same degree of horror as from that first shock. But the difficulty with this kind of weapon is to get near enough to the adversary to be able to use it effectively.

Torpedo boats were originally designed mainly for the purpose of torpedo attack. But these mosquito craft have been rendered practically harmless by the creation of a newer type of warship, the "destroyer"-itself a larger and swifter tor

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pedo boat, much more formidably gunned. Destroyers are now used as a "screen" to protect the big ships; but the torpedoes they carry have never proved to be of any value in war, because these vessels dare not approach an enemy's battleship or cruiser near enough to fire them.

Battleships and cruisers are themselves provided with torpedo tubes; but in no recorded instance have these been used with effect in a sea fight, for the simple reason that naval combatants under the conditions of modern warfare stand off and hammer each other at a distance. Up to the present time, therefore, the automobile torpedo has been utilized. effectively by one type of craft only, the submarine.

The submarine, however, does its work under serious disadvantages. To begin with, it is slow, being unable to travel

under water at a speed of more than eleven knots an hour. In addition, it is blind, except when it comes to the surface to look round. The "periscope" which it uses for this purpose-a sort of crab's eye arrangement thrust out above the waves-affords opportunity of vision for only a short distance, being so near the water, and is useless at night. Indeed, it is only under exceptional weather conditions, when the sea is comparatively calm and the atmosphere misty, that a submarine has much chance to do its work.

It follows, then, that what is wanted, in order to make the automobile torpedo an effective and reliable weapon, is a carrier that will be able to approach the enemy swiftly, with a fair degree of safety, and with a reasonable certainty of delivering the weapon accurately at the target. Admiral Fiske is of the opinion that the aeroplane can be made to fill all of these requirements. His idea is that the torpedo shall be held by suitable clamps beneath the flying machine, and

liberated therefrom at the proper moment by the aviator. As he suggests, the torpedo and aeroplane might be regarded unitedly as a flying-fish, which, when it dives, leaves its wings in the air.

A Whitehead torpedo is a cigarshaped affair of steel, sixteen feet long, with a conical attachable nose called a "war head", which contains two hundred fifty pounds of high explosive. The main body of the contrivance is a chamber holding air at a pressure of two thousand pounds to the square inch. When the projectile is fired, a pin is tripped which opens a valve and liberates the air in such a way as to run the machinery in the rear end, driving a pair of propellers.

The projectile can be discharged at a target with as much accuracy as a bullet fired from a gun. Automatically adjusting itself to the desired immersion, it so controls itself thereafter as to keep the direction in which it was aimed. Pursuing its course at fifteen feet below the surface, so as to strike beneath the armor of a battleship, it is kept automatically at that depth by a little rudder which turns up if the nose attempts to turn down, or vice versa. Inside of it spins a gyroscope, bringing it back into line if it tends to turn to right or left.

Thus it will be understood how a torpedo of this kind, dropped from an aeroplane, might be expected to accomplish the purpose desired. A battleship six hundred feet long affords a good-sized target, and the aviator, determining his aim by approaching the enemy's vessel head-on, ought to be able to hit such a mark with reasonable certainty at a distance of a mile. The resulting explosion and downward plunge of the wrecked ship would close the scene.

An automobile torpedo on being discharged will travel five miles. But in practice its effective range hardly exceeds two thousand yards, for accurate aiming at the target. Preferably, a starless night would be chosen for attack by the torpedo-carrying aeroplane, which might be launched from the deck of a scout ship. Rising to an elevation of two thousand

feet, the flying machine would be invisible in the darkness. On the other hand, the enemy's warships could be seen by the aviator, even though their lights were out, their hulls making black blots on the

sea.

Coming near, the aviator would volplane down to within ten or fifteen feet of the surface of the sea and, aiming at the ship he meant to strike, would pull the lever provided for the purpose, tripping the pin that actuates the machinery, and simultaneously drop the projectile into the water. Such an attack, indeed, might be made at only moderate risk in the daytime; for the gunners on board. the vessel could not hit an aeroplane falling rapidly downward. Their guns could not be changed in elevation and sighted quickly enough.

It is further suggested that a hangar ship might accompany a fleet of warships to shelter half a dozen or more torpedocarrying flying machines. Such a vessel would have to be of large size, with cruising radius and speed sufficient to enable her to keep up with a battle fleet or squadron of scout cruisers. She would carry a number of skilled aviators, and a sufficient force of specially trained mechanics to take care of the aeroplanes and keep them in repair.

The problem of taking wing from, or landing upon, a ship's deck has already been solved by aviators. Indeed, our own scout cruiser Birmingham was the first vessel used for a demonstration of this kind. Admiral Fiske is of opinion that torpedo-carrying aeroplanes might be employed with special effectiveness for attacking ships moored in harbors.

It is reported that the newest German Zeppelins are being fitted with torpedo tubes, and that they are practicing with these on Lake Constance, using rafts as targets. If this be true, it must mean that the idea of discharging submarine projectiles from the air-a curious paradox, when one comes to think of it-has already been adopted for use in the present war. Whether dirigibles or flying machines be utilized for the purpose, it