It is for Congress to inaugurate this great work of coast armament. The positive and practical experience of the Midvale Works and the · Cambria Works is to the extent of their facilities equal to that of foreign establishments, and these results are in a large degree, the outcome of high standards, close specifications and most rigid supervision and inspection, enforced by this Department. I venture the opinion that such important work can not be intrusted to better or more skillful hands than to the officers of the Ordnance Department of the Army.

Pneumatic gun-carriages.

Carriages for heavy cannon present one of the most important and most difficult problems to the ordnance officer. The best mechanical minds here and abroad have labored with most encouraging success to solve the problem, so as to satisfy all conditions of emplacement, all weights of heavy cannon, all forces generated by explosives. With the increase in size and weight of cannon man-power has had to give way to steam, compressed air, hydraulic appliances, in the handling and management of such heavy masses. Types of the best carriages known here or elsewhere should therefore be provided, as aids to the study and development of this vital necessity. A trial of the improved Powlett carriage should be authorized by an appropriation. It was first taken up by this Department, and its favorable action has induced further and more extended trial by our Navy. The conditions of use in the Army and Navy service are so different, that a further trial by us is in the interest of the public service.

The dynamite torpedo gun.

This modern ballistic engine has been so far perfected as to render it practicable to project to a considerable distance, by means of compressed air, large charges of high explosives with a safety, certainty, and accuracy of fire, which render it a source of great danger to the decks of hostile ships. More than this, an electric fuze, capable of being actuated by contact with salt water, has been devised and tested with promising success, which should more than double the value of the gun as a weapon for coast defense. If, as it is claimed, charges of 500 pounds of explosive gelatine or dynamite can be projected to a distance of from 2 to 3 miles, and detonated after entering the water, with a fair degree of probability that explosion will occur immediately under or near the hull of a ship, below the armor protection, the most destructive effects are to be expected-as ships of war are at present constructed. The result is much the same, though with perhaps less certainty of action, as that sought to be attained in defending a channel by means of fixed mines, but with the obvious advantage of being able to shift at will, as it were, the location of the "torpedo field" to any point, within range, taken up by the enemy's ship. The latter is thus placed at the disadvantage of

always being compelled to cruise over an area beset with submarine mines so long as it is within range of the gun. It is not intended, by implication even, that fixed mines are to be abandoned, but on the contrary that the two systems supplement each other into a vastly more powerful combination of explosives, and become a most essential adjunct to the heavy guns of great range and power, which are of necessity, as armor-piercing weapons, the basis of all armament for coast defense. I would recommend the purchase of one of these guns, say of 15-inch caliber, for exhaustive trials of gun and projectile, with the object of determining the full extent of their capacity and fitness for coast defense.

A Board of Officers was appointed January 26, 1886, by the Secretary of War for the purpose of witnessing trials with the dynamite torpedo gun, which for some months had been under experiment at Fort Ham ilton under the auspices of the War Department, and to report on its merits and suitability for the military service. But the company interested in this gun failed to make the necessary arrangements for the proposed trials and the board was ultimately dissolved without making any report.

The Stevens dynamite shell.

During the year further experiments have been made at the Ordnance Proving Ground in firing shell charged with high explosives from ordinary cannon by means of gunpowder. Among the devices of this class tested, and meriting favorable mention, is a shell invented by Mr. B. D. Stevens of Burlington, Vt. In the experiments with this shell, it was charged with explosive gelatine and repeatedly fired without premature explosion, from a 7-inch M. L. rifle using the battering charge for that gun. The results obtained are deemed of sufficient promise to justify a more extended trial, and the firings will be continued at an early day.

SIEGE MATERIAL.

The 5-inch B. L. siege gun and its carriage, and the 7-inch B. L. howitzer, which were under fabrication at the Watertown Arsenal, have been completed and sent to the proving ground. The powders and projectiles required for their trials are now being procured, so that both of these guns should be heard from at an early day.

FIELD MATERIAL.

During the past year twenty-five 3.2-inch B. L. field guns, steel, of the model tested in 1885, and recommended for issue to the service by the board for testing rifled cannon and projectiles, have been completed, and part have been issued to the service. Twenty-five new steel gun carriages have also been made at the National Armory, on the design of Colonel Buffington, and a part issued.

The Midvale Steel Company has under fabrication the forgings for 25 additional 3.2-inch guns, and Colonel Buffington has in hand the manufacture of an equal number of carriages.

An improved limber, caisson, battery wagon and forge, for the new field guns, have been made a special study during the past year by Colonel Buffington, Ordnance Department and Major E. B. Williston, Third Artillery. The labors of these officers have now reached, it is believed, a satisfactory completion, and the manufacture of these new carriages, will be commenced at once for issue and trial.

With the exception of the small number of 3.2-inch B. L. steel guns above stated as completed, or now under manufacture, the condition of our field armament is substantially as noted in my last report. There is in store only the old muzzle-loading guns, of very limited power, representing a system of twenty-five years ago, and now obsolete; while there are absolutely no serviceable carriages. A few old wooden carriages have been repaired, so as to suffice for merely nominal garrison service, but are not adequate for active field service, nor for the increased charges of improved powder that can be used with the old guns. The necessity for having always on hand and ready for immedi ate issue a very considerable number of field guns, with their appropriate carriages, ammunition, etc., is almost as great as that for a reserve supply of small-arms. A suitable artillery complement is almost as indispensable to the outfit of any armed force, however small it may be or whatever the object to be accomplished by it, as the infantry complement itself. And yet, notwithstanding the repeated representations made in its annual reports, the Department is to-day in the deplorable condition of possessing but a couple of dozen of modern steel field guns, and has absolutely no suitably equipped field batteries, should an emergency, such as may arise at any time, require them. In my annual estimates for the next fiscal year, I have asked for an appropriation of $225,000 for the purchase of steel guns, their carriages and ammunition. This is a small sum, but it will procure not less than 60 steel guns fully equipped, and supplied with ammunition: or taking the 3.2 inch guns now on hand and under manufacture into consideration it should insure the full and proper equipment of about 100 field guns.

In connection with the subject of the 3.2-inch steel field guns, attention is invited to the very interesting report, Appendix 38, of Mr. James E. Howard, C. E., in special charge of the testing machine at Watertown Arsenal, on some tests made by him, under instructions from this office, to determine the initial strains in some tempered and annealed steel cylinders. The cylinders were taken from the ends of tubes for the 3.2-inch guns, and represented metal that had been oil-tempered and subsequently annealed, and also metal that had been simply tempered without annealing. Thin concentric rings were detached from the cylinders, then from a comparison of their diameters-as measured before and after separation from the cylinders-the directions and intensities of the initial strains were ascertained. In this way it was found that in the simply tempered cylinder the initial strains were very severe, bordering, in some of the rings, close on to the elastic limit,

while in the other cylinders, of similar metal similarly treated except that it was annealed after tempering, the initial strains had been prac tically eliminated. The immense advantage to be derived from annealing tempered steel was thus clearly demonstrated. As bearing on this subject, and as indicating also the superiority of steel so treated to steel simply annealed but not tempered, the following test may be mentioned. In the first or experimental 3.2-inch gun the tube was made from a steel that had been annealed but not tempered, and the gun sustained very satisfactorily a test for endurance of over 2,200 rounds. The new lot of 3.2-inch guns were made from steel that had been oiltempered and afterwards annealed, and which before treatment was probably a little softer in quality than that used in the first gun. To compare the relative stiffness of the two qualities of steel, the Ordnance Board was directed to fire 100 rounds with full charges from one of the new guns, and to star gauge the bore after the sixtieth and one hundredth rounds. A tabular comparison of the star-gauging records of the two guns is contained in Appendix 39, which strongly attests the superiority of the oil-tempered and annealed metal. No appreciable enlargement of the bore had occurred with the new gun during the 100 rounds, except near the bottom where the forcing of the projectile always makes itself felt, and even there it was less than with the other gun, which latter also showed an enlargement all along the bore gradually diminishing from 0.009 at the bottom to 0.001 at the muzzle.

Field artillery harness.

Maj. E. B. Williston, Third Artillery, has submitted a very interesting report on his improvements in artillery harness, which is published herewith, Appendix 41. His long practical experience during and since the war as a light battery commander has made him an authority on this subject, and this Department has been fortunate in having the results of his study and thought and his valuable assistance in perfecting the details of this most important arm of the service.

MOUNTAIN MATERIAL.

The ten sets of packing outfit for the Hotchkiss mountain gun, designed by Lieutenant-Colonel Flagler, have been completed and will be at once issued to the service for trial and report.

TESTS OF ORDNANCE.

No further firings have been made during the year with the 12-inch B. L. rifle, cast-iron, or the 12-inch M. L. mortar. With regard to the first piece, after being fired 137 rounds with a maximum charge of 265 pounds powder and a projectile of 800 pounds-the mean pressure for 100 rounds being about 28,000 pounds, or 12 tons-the chamber and rifled bore became so badly eroded that the board for testing rifled cannon reported it as in an unsafe condition for further firing, although the board thought that its life would still be prolonged by the introduction

of a steel lining. The Department had no funds for that purpose, and the board deemed it best to suspend action in reference to this gun until after the trial of the new 12-inch B. L. rifle, cast-iron, which is provided with a steel tube.-See Appendix 10, Report of the Chief of Ordnance, 1886. The firings of the 12-inch M. L. mortar had proceeded beyond 400 rounds, establishing beyond doubt the ample resistance of the piece, but the board for testing rifled cannon were not satisfied with the accuracy of fire and decided to suspend firing until the new 12-inch B. L. mortar could be tested in comparison.

The 8-inch B. L. rifle, steel.

As stated in my last report the 8-inch B. L. rifle, steel, after being fired 24 rounds, was returned to the West Point Foundry to have the chase hooping extended to the muzzle, a distance of some 90 inches. It was noticed after the exterior of the chase had been turned off for the reception of the hoops, that the previously observed enlargement of the bore had undergone a very considerable contraction, thus confirming the view held by the Department, that, through imperfect annealing, the initial strains due to tempering had not been removed. As the tube for this gun was obtained from abroad, and the manufacture did not take place under the supervision of the Department, its acceptance could be conditioned only on the mechanical qualities of the test specimens and the general good repute of the manufacturers. The actual condition therefore of the tube, as developed by the firings, could scarcely have been guarded against. After the hoops had been put on the chase, the remaining enlargement of the bore wholly disappeared, giving place, as was designed, to a light compression. Before returning the gun to the Proving Ground a slight modification was made in the breech mechanism to overcome the sticking of the block after firing, and which in the subsequent firings has worked very satisfactorily.

In resuming the firings with this gun, some new samples of brown prismatic powder, made by the Messrs. Du Pont, were employed, and further trials were made with increased charges of the German brown powder. The results obtained in the previous firings with a charge of 100 pounds Du Pont's P. A. brown prismatic powder and a 286-pound projectile were a velocity of 1,820 feet and a pressure of 35,450 pounds per square inch-see page 14 of my last annual report-the corresponding energy of the shot at the muzzle being 6,567 foot-tons. With the increased charge of the new Du Pont powder and the German powder, the following results were obtained: