importance. It is readily possible to construct say a 6-inch gun of steel, weighing not over 3000 pounds, which will throw a shell containing 50 pounds of explosive gelatine to a range of at least 4500 yards. For this purpose the ease with which it may be dismounted, separated, and reassembled in the field gives it a peculiar advantage. The weight of the heaviest piece of a 6-inch gun would be 950 pounds (of a 4-inch it is 260 pounds). The practicability of transporting such a gun to localities and positions where it would be impossible to take an ordinary gun of equivalent effectiveness is of evident value. One single wrench and sledge-hammer are the only tools necessary to take it apart and reassemble, each operation being easily performed within an hour.

The 4-inch gun described weighs complete 1300 pounds, its mount 750 pounds. The gun has been fired about 200 rounds with full charges. It has functioned perfectly in every particular, the recoil easy, the breech mechanisms have worked well, and whenever attempts have been made at target practice remarkable uniformity and accuracy have been attained. Pressures have been repeatedly measured, and at no time, using same weight projectile and powder charge, has there been a perceptible difference. The limit of available range has been 2300 yards, and whenever desired this has readily been reached and could have been exceeded.

A number of full charges of explosive gelatine and also of gun-cotton have been fired, although most of the experiments have been with either dummy projectiles or for testing fuzes, with shells loaded with small charges of sporting powder.

This being the first and only practical gun built on this system, the action of the powder and in fact the whole principle being out of the ordinary, it is not to be expected that the best attainable results have been reached. So far as smoothness, easy action, recoil, and uniform action of powder is concerned nothing better could be desired.

Range of course depends entirely on the amount of force applied behind the projectile, and it will be seen that this can be increased simply by increasing the diameter of the side tubes, that is, increasing the volume of air-space between powder and projectile. Increase of this volume will permit the burn

The volume of air and gases thus increased, it is apparent that the pressure will follow the projectile farther in the bore, giving greater initial velocity. It is regretted that a series of actual pressure tests along the side and main tubes has not been made, although it has been the intention to do so. Such tests will be made, however, at the first opportunity. It is believed that with this data it would be quite possible to so design a gun of this caliber that the range would be doubled without danger of increasing the pressure beyond a perfectly safe limit for projectiles loaded with the most sensitive explosive.

Altogether this trial gun has given great promise, and there can be no doubt that it has demonstrated its value as a practical weapon.

It will perhaps be interesting, and at least it is but just to the original inventor, to give a résumé of the development of the scheme and credit its origin where it belongs.

The inventor, Dana Dudley, who deserves whatever credit is due, worked on the principle of which he was clearly the discoverer for a number of years, but was without the means to develop it properly. He had, however, made a gun of 1-inch steam-pipe, which gave promising results and proved its feasibility.

In 1888 the Hotchkiss Ordnance Co. acquired control of the Howell torpedo, and soon after made a contract with the Navy Department for a number, together with the necessary launchingtubes. As no practical design then existed for the tubes, the question suddenly became an important one. It was thought necessary to use compressed air for launching, but the pipes for this in addition to steam pipes for the motor would have added to the existing complication.

The writer, who was then with the company working on the development of the torpedo, accidentally heard that Mr. Dudley had some sort of an air-gun. By request, Mr. Dudley showed and fired the gun, when at once it was evident that the scheme was applicable for launching-tubes. A temporary affair was built, and proving entirely satisfactory, the launching gear as now used by the company exclusively, and installed on several vessels in the Navy, was at once developed. No change has been made or found necessary in the application of the principle to

of its value as a gun for throwing high explosives, which was the original idea of the inventor. No opportunity presented itself for working out the scheme until the past year. Now that a start has been made and the principle demonstrated on a practical scale, it is believed possible, with encouragement, to quickly develop the system until it takes its place along with the wellestablished standard weapons-the gun, torpedo, and ram.

Since the above article was written an official test has been given of the 4-inch gun before General Miles, the Board of Ordnance and Fortification, and Commodore Sampson, Chief of Bureau of Ordnance, Navy Department.

At this test 5 shells, each loaded with 13 pounds of explosive gelatine, were fired to sea, a distance of about 1900 yards, and exploded. These shots were perfectly satisfactory in every respect to all present. They were all that could be desired, being straight, true, steady and uniform in flight. Unfortunately, just afterward, during the practice at a target, the main tube was ruptured by the explosion within the bore of a shell loaded with 5 pounds of blasting powder. This accident, while putting an abrupt close to the tests, did not in any way count against the gun, as it was due to circumstances in no way related to the action or principle of the system, but was clearly due to a faulty fuze exploding the charge; and the result, so far as destructive effects are concerned, would have been much greater even had the shell been in the bore of say one of the service steel guns. The fuze was not one of those employed in the explosive gelatine tests and which so thoroughly proved their safety qualities, but one of entirely different design, made with a view of simplifying the construction. It is hardly necessary to say that this fuze has been condemned for future use.

Accidents of this kind generally and naturally serve as a check to the development of a new scheme, but it should be remembered that it was not the gun which exploded. It was a shell in the bore, and there are numerous parallel cases with ordinary guns and with corresponding results on record.

It was simply unfortunate that the accident happened at this