OK TF 
 
 tottsitir tff 
 
 JVo. 
 
 Division 
 
 Range 
 
 Shelf 
 
 Received. ..^zhcAsvu?.. 6.7 1 873- 
 
 PRESENTED TO THE 
 
 |S 
 
 Library of the University of California, I 
 
 
40TH CONGRESS, \ SENATE. ( EEP. COM. 
 
 3d Session. ( ) No. 266. 
 
 IN THE SENATE OF THE UNITED STATES. 
 
 FEBRUARY 15, 1869. 
 
 FEBRUARY 25, 1869. Ordered to be printed, and that two thousand additional copies be 
 printed for the use of the Senate. 
 
 Mr. HOWARD, from the Joint Committee on Ordnance, submitted the 
 
 following 
 
 ,, EEPORT. * ' 
 
 The Joint Committee appointed under the resolution of the Senate and 
 House of Representatives of the 30th of March, 1867, to investigate the 
 purchases, contracts, and experiments of the ordnance department, having 
 completed their labors as far as relates to experiments upon heavy ordnance, 
 submit the following report thereon: 
 
 Since the war of 1812 there has been a tendency on the part of all 
 nations to increase the size of their artillery, and within the last few 
 years the important change made in systems of defence by the intro- 
 duction of armor-plating, necessitating more powerful engines of attack, 
 has resulted in enormously increasing the -weight and calibres of guns. 
 This increase of calibre early developed a remarkable and puzzling fact, 
 namely, that systems of fabrication which, with small calibres, gave 
 good endurance when applied to large guns, proved to be failures. 
 Elaborate experiments, stretching over a period of years, have been 
 carried on in Europe and America to solve this problem, and many new 
 systems, which in theory promised success, have been successively tried 
 and abandoned; nearly all of them succeeding well in small guns, but 
 failing in large ones, and failing, too, in a manner which apparently 
 increased the complication of the problem a gun frequently enduring 
 over 2,000 rounds, while another, precisely similar, would explode after 
 a few fires ; while guns made of the strongest material seemed generally 
 to prove the weakest when put to the test. No nation at present has 
 guns of large calibre the endurance of which can be estimated with any 
 degree of certainty. The difficulty, serious enough with smooth-bore 
 guns, is greatly increased in rifles, the 30-pounder being the largest rifled 
 gun that has exhibited even comparatively good endurance in this coun- 
 try, while in Europe no more satisfactory result has been obtained. 
 
 This unreliability of heavy ordnance, from its tendency to rupture, 
 has been heretofore supposed to be attributable wholly to the expan- 
 sive or projectile force of the powder undergoing combustion, and the 
 efforts of inventors have been directed to devising new means the better" 
 to restrain this force, and on failing, it has been common for them to 
 attribute enormous pressure to the gases of the powder in order to 
 account for the bursting of the guns ; but the fallacy of this reasoning 
 is shown by the fact that the pressure of powder has been found to be 
 uniform, as it gives uniform range to the projectile, and at times does 
 not burst a gun made of weaker material than others which have burst 
 
2 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 when fired with like charges and under like circumstances. Acting 
 upon this mode of reasoning, two means of increasing the strength of 
 the gun so as to restrain the force of the powder have been employed ; 
 the use of stronger material, such as steel and wrought iron, and methods 
 of fabrication which secure a compressing tension in the metal. Both 
 of these means are employed in the English Armstrong, Fraser, Whit- 
 worth, and Blakely guns, while in the Krupp guns of Prussia, the 
 strength of the metal (steel) is alone relied on, and in the Rodman hol- 
 low-cast guns of this government tension is the restraining force chiefly 
 sought. These two principles have been embodied to a greater or less 
 extent in all the various systems in this country and Europe since the 
 solid mode of casting was abandoned in our service for the hollow mode 
 introduced by Eodman for cast-iron guns; since which, in this country, 
 reliance has been placed upon cast iron with initial tension from the 
 mode of cooling the gun, or cast iron banded with wrought iron, as in 
 the Parrott gun. In England the same theory was introduced in the 
 Armstrong and Whitworth guns, using wrought iron, or a combination 
 of wrought iron and steel, in built-up guns, and cast iron, wrought iron, 
 and steel in various combinations, as in the Blakely system. Krupp, of 
 Prussia, has made solid, dense, and homogeneous guns of large calibre 
 of steel alone, yet his very largest guns have been built up also. 
 
 None of these systems have proved successful in preventing the burst- 
 ing of guns, or giving them uniformly reliable endurance. The com- 
 mittee do not think it necessary to discuss further the various European 
 systems of gun-making. None of them have shown exemption from the 
 rule of failure, and experiments with them on the part of this govern- 
 ment would be of doubtful value. The Rodman system, employing cast 
 iron, has had the merit of cheapness, and when applied to smooth-bore 
 guns has had claimed for it superiority over European sytems, but it 
 must be considered to be equally a failure with the others, especially 
 when applied to rifled guns. The Chief of Ordnance of the navy, in his 
 last report, acknowledges this to be the case. He says: 
 
 Opinions differ quite as widely in regard to the preferable mode of developing ordnance 
 power, whether it shall be by smooth or rifled bores, by loading at breech or muzzle, made 
 from iron, cast or wrought, or from steel, solid or in connected parts. The relation of mass 
 to velocity is also unsettled. In fact, the question involves the necessity of going back to 
 fundamental principles, and starting thence by well-conducted experiments. 
 
 It therefore appears that, notwithstanding a series of elaborate experi- 
 ments, extending over a long period of years, and the practical experience 
 of our recent war, the ordnance officers of the government have not yet 
 determined upon even the fundamental principles of their art, and possess 
 no positive knowledge of the problem they have so long sought to solve. 
 Mechanics is an exact science, and ignorance of that branch of it involved 
 in the construction of guns Avould seem to show either want of knowledge 
 of its principles, failure to understand their application, or superficiality 
 of investigation, surprising in men whose minds have been from boyhood 
 trained in the direction of a specialty. 
 
 Each system of guns introduced in our service has been subjected in 
 proof to tests supposed to demonstrate beyond question its ability to 
 perform the work required of it, but each has failed when submitted to 
 the real test of service. In the operations upon Morris island 22 large 
 guns was the greatest number mounted at one time, yet 50 in all burst 
 during the siege, as is shown by the evidence of General Gillmore. In the 
 attack on Fort Fisher all the Parrott guns in the fleet burst, according 
 to the report of Admiral Porter. By the bursting of five of these guns 
 at the first bombardment 45 persons were killed and wounded, while 
 only 11 were killed or wounded by the projectiles from the enemy's guns 
 
EXPERIMENTS ON HEAVY ORDNANCE. 3 
 
 during the attack. The battle of Fort Fisher was the only occasion 
 during the war when rifled guns of large calibre were fired rapidly and 
 continuously for a great number of rounds. 
 
 The failure to discover the weakness of these guns before putting them 
 in the field, or on board ship for actual service, must be attributed to a 
 defect in the system of proof employed. These systems appear to have 
 been comparatively valueless, and to have proven little or nothing re- 
 specting the ability of the gun to perform the work expected of it in 
 battle. The committee cannot learn that any method of proof has been 
 practiced in the army or navy which subjects guns to the tests they must 
 endure when first brought into actual combat, namely, rapid and con- 
 tinuous firing, with intervals only sufficient for loading. Excessive 
 charges have been used and a great number of rounds fired, but no at- 
 tempt has been made to copy upon the proving ground the conditions 
 existing in battle. In the new conditions developed by the rapid and 
 long-continued firing in battle, not present during the slow and careful 
 firing when in process of proof, it would seem must be found the cause 
 of the frequent rupture of the guns. The most important new condition 
 present during rapid fire would seem to be the communication of a 
 greater amount of heat to the bore of the gun, having a tendency, by its 
 expansive force, to aid the powder in effecting a rupture. If the gun 
 be fired rapidly so as to allow little time for the bore to cool between 
 each discharge, it is believed that the heat communicated would exert 
 a powerful expanding force ; while if there should be long intervals 
 between the shots, even if the charges were excessive, sufficient heat to 
 burst the gun might not be communicated to the interior. In reports of 
 ordnance officers, the effect of unequal cooling in inaugurating unfavor- 
 able tensions in a gun cast solid and cooled wholly from the outside 
 is treated at length, and it is shown that fissures and ruptures have 
 resulted from the contraction towards the outside as the gun cooled, 
 and it is stated that three-fifths of the strength of the gun is ex- 
 pended in this manner, leaving only two-fifths to restrain the pressure 
 of the powder. The hollow mode of casting of the Eodnian system, 
 and the band of wrought iron applied to the Parrott gun, were in- 
 tended to utilize this force of contraction, by assisting the strength 
 of the iron to restrain the pressure of the powder. It was afterwards 
 noticed that several of the Eodnian guns casfc hollow, and cooled 
 from the interior, burst in the foundry from the excess of this force 
 of contraction exerted in the opposite direction from that before 
 referred to. If the force with which metals contract when cooled is 
 shown to be so potent as to break the gun from the inside when 
 cooled from the outside, and from the outside when cooled from the 
 interior, it can be seen that if the gun be in a state of tension, which 
 has the tendency to compress the metal of the interior and extend 
 the exterior, the heat afterwards communicated to the surface of the 
 bore by the burning powder, or by friction of the moving charge, would 
 assist the pressure of the powder to break the gun, especially if the gun 
 should be fired a number of rounds in quick succession. This additional 
 force being considered, it may be possible to determine why guns made 
 of the strongest material are more liable to burst than those made of 
 weaker iron, and why the accidents occur most frequently during 
 battle, when the gun is fired more rapidly than at the time of proof, 
 when it is usually fired slowly. Forces known to be sufficient to actu- 
 ally break large masses of iron, spontaneously, as it were, should not be 
 overlooked while treating so intricate a subject as this of heavy guns. 
 Mr. Holley refers to the rupture of a large mass of wrought iron pre- 
 
4 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 pared by Mr. Mallet, in England, as attributable to " the force of con- 
 traction from the centre toward the exterior as the mass cooled." Such 
 ruptures of large steamboat shafts are frequently noticed, and con- 
 traction of this kind may explain the fissures in large wrought-iron guns 
 which have been noticed, as well as the soft and easily compressed nature 
 of the iron in the interior of the mass of all classes of large guns. 
 
 The fact that the ordnance officers of the government find it necessary, 
 at this late day, to return to the sudiments of their art and begin their 
 experiments anew, as stated in the report of the Chief of Ordnance of the 
 navy, shows a defect in the system upon which experiments have heretofore 
 been conducted, and in the organization of the ordnance departments, call- 
 ing for a remedy. The difficulty appears to have been two-fold : First, the 
 ordnance officers, knowing their positions secure to them for life, have 
 not felt the incentive to exertion and improvement which stimulates men 
 not in government employ, and they have become attached to routine 
 and to the traditions of their corps, jealous of innovation and new ideas, 
 and slow to adopt improvements. An illustration of this is found in 
 the fact that the late war was fought with muzzle-loading guns, (with 
 the exception of carbines for cavalry,) although a variety of excellent 
 breech-loaders were urged upon the attention of the government con- 
 stantly, and the honor Avas reserved for Prussia, with a weapon inferior to 
 many American inventions, to demonstrate the immeasurable superiority 
 of breech-loading guns. In the second place, these officers, educated to a 
 specialty and proud of their positions, come to look upon themselves as 
 possessing all the knowledge extant upon the subject of ordnance, and 
 regard citizen inventors and mechanics who offer improvements in arms 
 as ignorant and designing persons, and pretentious innovators, who 
 have no claim to consideration. Instead of encouraging the inventive 
 talent of the country, these officers seem to have constantly discouraged 
 it, and many complaints of improper and oppressive treatment have 
 been laid before the committee by persons who have sought to draw the 
 attention of the proper authorities to what were supposed to be vital 
 principles connected with their art. Another difficulty that has retarded 
 progress in the science of ordnance has been the fact that prominent 
 officers have been inventors of arms, and have possessed sufficient influ- 
 ence to secure the adoption arid retention in service of their inventions, 
 frequently without due regard to the question of real merit, and to the 
 prejudice of other and better devices brought forward by citizens, or 
 developed in other countries. A further difficulty, calling for a remedy, 
 lies in the want of co-operation between the war and navy ordnance 
 bureaus. Great diversity exists in the practice of the two branches of 
 the service respecting the arms adopted, and the manner of proving, 
 mounting, and using the same. The calibres, models, chambers and 
 ammunition of the navy guns are entirely unlike those in use in the 
 army. For example, the navy 12-pounder boat howitzer has a calibre 
 of 3.4 inches, while the army 12-pounder guns are of the calibres of 3, 
 3.2, 3.67, and 3.8 inches. The chamber of the navy gun is of parabolic 
 form, while the army gun either has a cycloidal chamber or none at all. 
 The models of the two guns are entirely different, so that neither could 
 be used on the carriage of the other; the army guns being furnished 
 with trunnions, and the navy gun having, in some cases, the loop 
 and loop-bolt of the old carronade. The system of sighting is also 
 different. A gunner in one arm of the service, without special instruc- 
 tion, could not use a gun belonging to the other; one being grad- 
 uated to seconds of time of the flight of the shot, and the other 
 to degrees of elevation. The navy has 8, 9, 11, and 13-inch smooth 
 
EXPERIMENTS ON HEAVY ORDNANCE. 5 
 
 bores, while the army guns are of the calibres of 6, 8, 10, and 
 12 inches. In the guns of the two branches of the service there 
 is no uniformity, in either rifle or smooth-bore, in the 20 calibres 
 adopted below the calibre of the 32-pounders. It is impossible to 
 use navy ammunition in an army gun or army ammunition in a navy 
 gun. Co-operation between the army and navy while in active service 
 is thus greatly restricted, and in some cases has been entirely prevented. 
 Offensive operations on the part of a joint expedition of the two might 
 be brought to an end by the want of projectiles for the land forces, while 
 the ships of the navy possessed a surplus of the very articles required, 
 which could not be used by the land forces. Not a single advantage 
 is claimed for this lack of uniformity, while the disadvantages are very 
 numerous and apparent. It has grown out of the fact that officers in 
 the two branches of the service have succeeded in securing the adoption 
 of their own inventions, and the rivalry existing between them has pre- 
 vented fair competitive trials of the various devices and systems advo- 
 cated by each, neither being willing to admit the merit of the other's 
 inventions, or to utilize the knowledge gained either by their successes 
 or failures. The experiments, being duplicated on account of this jeal- 
 ousy, have been, necessarily, needlessly expensive. A further increased 
 expense results, in time of war, from maintaining two separate organiza- 
 tions for the procurement of arms. The two ordnance departments are 
 brought into competition with each other in the matter of contracts and 
 purchases of war material from the private workshops and factories of 
 the country, thus putting the government in the attitude of bidding 
 against itself. 
 
 The investigations of the committee lead them to the following con- 
 clusions : 
 
 1. That no more heavy guns should be purchased for mounting in the 
 fortifications or use on shipboard until such improvements are made in 
 methods of fabrication as will insure more reliable endurance than has 
 heretofore been exhibited. 
 
 2. That the Rodman system of gun-making, while partially successful 
 in smooth-bores and small calibres, has so far failed in rifles of large cali 
 bre as to show it to be unworthy of further confidence. Recent improve- 
 ments in defensive works and armor-plating render heavy rifled guns the 
 most efficient means of attack, and no system of fabrication which does 
 not furnish such guns should be adopted or continued. The principle of 
 initial tension, which is the basis of the Rodman system, appears to be 
 of doubtful utility, as applied by General Rodman, especially for rifled 
 guns. This tension, it is admitted, gradually disappears from the gun 
 with age, and in time is entirely lost. 
 
 3. That guns cast solid, in the manner practiced in the navy under 
 the direction of Rear- Admiral Dahlgren, while exhibiting satisfactory 
 endurance as smooth-bores with small charges and hollow projectiles, 
 have not the requisite strength for rifles of large calibre. This mode of 
 casting seems to be defective in principle, as the tensions inaugurated 
 in cooling have a tendency to aid the powder to rupture the gun. 
 
 4. That experiments should be at once conducted for the purpose of 
 ascertaining the real cause of the bursting of heavy guns, and of deter- 
 mining upon some method of fabrication that will secure uniform endu- 
 rance. 
 
 5. That every encouragement should be given to inventors, and a full 
 and fair trial accorded to all devices offered to the government that 
 promise a solution of the ordnance problem. 
 
 6. That more efficient means for harbor defence should be adopted. 
 
6 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 The late war demonstrated that sand was the best material for defensive 
 works, and that forts of masonry, such as we have now mainly to rely upon 
 for the protection of our seaboard cities, are inefficient to prevent the 
 passage of armored, or even wooden, vessels. The destruction of such 
 defences is only a question of time to ordinary guns of heavy calibre. 
 It was also demonstrated that forts alone, of whatever character, can- 
 not resist the entrance to harbors of powerfully armed ships if the pre- 
 ponderance of guns on the assailing fleet is sufficient. In the opinion 
 of the committee, obstructions must be largely relied upon for harbor 
 defence, in connection with properly constructed fortifications. 
 
 7. That no officer of the army or navy should be allowed to receive a 
 patent for any article required, or likely to be required, for use in those 
 branches of the public service, or to be in any way interested in the 
 manufacture or procurement of such articles. It should be the duty of 
 Congress to recognize by suitable rewards the services of such officers 
 as might make inventions of especial value to the government. 
 
 8. That the ordnance department of the army can be entirely abolished 
 with great advantage as to economy, and without detriment to the good 
 of the service. The duties now performed by officers of that corps could 
 be performed by officers detailed from the artillery service, under the 
 direction of a chief stationed at Washington. In this manner the whole 
 expense of the ordnance establishment would be saved, and artillery 
 officers, who have not only scientific training but practical experience, 
 would have a voice in the selection of the guns and ammunition they 
 are required to use. 
 
 The committee are of the opinion that for the reasons shown the inter- 
 ests of the public service demand a change in the system of procuring 
 ordnance and ordnance stores, and the manner of conducting experiments 
 with a view to determining the value of the same. The present system 
 has failed to answer the purpose for which it was designed, and the 
 TJnited States is in the position to-day of a nation having a vast coast- 
 line to defend, and a large navy, without a single rifled gun of large 
 calibre, and a corps of ordnance officers who have thus far failed to dis- 
 cover a remedy for the failure of the guns, or to master the rudiments 
 of the science in which they have been trained at the public expense. 
 The importance of an immediate change is shown by the fact that the 
 Chief of Ordnance of the army asks for appropriations to purchase over 
 1,900 guns to arm the forts, not of a new and better system, to be 
 decided upon after more thorough and careful experiment, but of a 
 kind that experience has shown to be inferior in range and penetration 
 to the guns of foreign powers, and unreliable as to endurance. 
 
 It is proposed that 85 of these guns shall be smooth-bores of 20-inch 
 calibre, 490 of 15-inch calibre, and 600 of 13-inch calibre. The experience 
 of all nations goes to prove that the most effective way of developing 
 ordnance power is by rifled guns. To return to smooth-bores, throwing 
 huge spherical masses of iron with low velocities, is to disregard all 
 modern progress in the science of gunnery, and to go back to the arm sin 
 use two centuries ago. Furthermore, the advisability of using guns of 
 such great size is very doubtful, for the slowness with which they can be 
 handled and fired makes them less effective than smaller guns delivering 
 a more rapid fire. Two hundred of the guns required it is proposed shall 
 be Eodman 12-inch rifles, notwithstanding all of that class of guns here- 
 tofore procured for the army or navy and subjected to test have either 
 burst disastrously before the lowest reasonable test has been completed, 
 or have given such indications of failing, after a few rounds, as to be 
 considered unsafe. It is proposed also to purchase 610 10-inch Eodman 
 
EXPERIMENTS ON HEAVY ORDNANCE. 7 
 
 rifles, although the committee cannot learn that any gun of this class 
 has ever been subjected to test in this country, except the Parrott rifles 
 of that calibre, which are acknowledged failures, having been condemned 
 by botji branches of the service. 
 
 No progress towards obtaining better guns is likely to be made while 
 the ordnance bureaus are organized as at present ; and the committee 
 deem the best way to secure such impartially conducted experiments 
 as will determine with certainty what are the best arms, and to insure 
 greater economy and regard for the public interests in their purchase 
 and adoption^ is in the formation of a mixed ordnance commission 
 composed of officers of high character detailed from both the army and 
 navy, who shall have no interest in patents on devices for arms. The 
 committee report the accompanying bill, based upon the conclusions 
 before set forth herein, and recommend its passage. 
 
APPENDIX A. 
 
 Testimony. 
 
 WASHINGTON, D. C., November 7, 1867. 
 HORATIO AMES sworn and examined. 
 
 By the CHAIRMAN pro tern. : 
 
 1. Question. What is your residence and occupation, and have you 
 had any experience in the manufacture of heavy guns or ordnance ? 
 
 Answer. I reside in Salisbury, Connecticut, and my occupation is, and 
 has been for the last 30 years, in the manufacture of wrought iron. 
 
 2. Q. Will you state whether you have had any contract with the 
 Kavy Department for the manufacture of ordnance j and if so, when and 
 of what calibre and description such guns were to be ; and, generally, 
 what were the terms of the contract, stating also whether you have 
 delivered the guns or they have been accepted from you ; and if not, 
 why they have not been so delivered or accepted, and where they are 
 now ; and give a general history of the whole transaction ? 
 
 A. In the summer of 1861 1 conceived the idea of making a wrought- 
 iron rifled cannon, and applied to the Navy Department for a contract, 
 and received an order to make five 50-pounders. These guns were made 
 at great loss to me, it being an experiment. One of the guns was fired 
 1,630 times without essential injury. Another of the lot was made into 
 an 80-pounder by enlarging the bore from five and one-tenth inches to six 
 inches, and fired 480 times without damage. Six of these guns were 
 received and paid for. In the fall of 1803 President Lincoln gave me 
 an order for 15 rifled guns of the largest calibre I would undertake to 
 make, leaving the size, shape, and calibre to me. These guns were com- 
 pleted in about a year and a half. One of them was fired 700 times 
 with more and heavier charges than any gun has been knoAvn to stand, 
 as the report of General Gillmore, Colonel T. T. S. Laidley, and Commo- 
 dore Hunt will show. Two of these 15 guns came apart in proof. These 
 guns weighed over 19,01)0 pounds each, and our machinery, tools, &c., 
 were not large enough to manage the work successfully. In the winter 
 of 1865 I received another contract from the Navy Department, or an 
 order, to make 11 guns, corresponding to the one proved at Bridgeport. 
 These gnus were made, and in August, 1865, one was ready for proof. 
 The government reserved to itself the manner of rifling the guns.' Two 
 of these guns were rifled in different methods, by order of the depart- 
 ment, of untried or experimental kinds ; and although the guns were 
 never tried, to know if the rifling was good or bad, they were abandoned 
 and new rifling was put into two more guns of 60-feet twist, which 
 insured their destruction, as there was not twist enough in them to give 
 the shot the proper rotary motion. Four of these guns were merely 
 fired to burst or otherwise destroy them. Each was merely fired into a 
 bank of earth without reference to precision, range, or velocity. The 
 fifteenth gun, at my request, was fired for range, at Bridgeport, and it 
 was judged that the twist was too slow to do good work. Besides, the 
 powder which was ordered, and believed to be 1,450 feet velocity, gave. 
 
10 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 when proved, but 1,100 to 1,200 feet. In fact, nothing of their quality 
 has been established except that they cannot be burst. The complaint 
 that the bore has been enlarged by tiring, which is not a very serious 
 one, can be remedied by firing the gun with heavy charges when one- 
 tenth inch below size, and will so compress the metal that it may be 
 fired a thousand times with heavy charges, and not materially further 
 enlarge. The cracks spoken of in the report are mere fissures, which 
 are not dangerous, and have not so proved. All wrought iron is liable 
 to show slight fissures, which do not impair its value, None have burst 
 in consequence of these fissures, and they can scarcely be called imper- 
 fections. In comparison with wrought-iron guns made in this country 
 and in Europe, they would be considered perfect. At any rate, they 
 have stood double the ammunition at the charge any gun we have has 
 endured. Were you to examine these guns now you would have no hes- 
 itation in pronouncing them good in all respects conforming to the con- 
 tract. The contract for these guns states explicitly that the normal 
 charge for them shall be 10 pounds or 12 pounds. Yet none of them 
 have been fired with these charges to show their endurance. It is known 
 that the istrain upon a rifled gun is twice and a half that upon a smooth- 
 bore gun, and that 40,000 pounds pressure upon the square inch of the 
 bore is the standard strain of common powder. Yet my gun has had 
 used in it powder more than twice as strong, which I believe has four 
 times the tendency to burst the gun. English powder gives even less 
 than 40,000 pounds to the inch. These 100-pounder guns have been 
 made of the kind of material called for by the contract, and are better 
 guns than the one which the contract specifies they shall be like. A 
 commission was .called to examine these guns, on the question whether 
 these " were suitable and proper guns to be put on board ship." They 
 decided they were not, because they had been fired with excessive 
 charges, greater than they would ever be called upon to bear. The 
 department had already decided the question, "that no gun should be 
 put on board ship that had been fired to excessive proof." This commis- 
 sion also recommended that they be further fired with the charges named 
 in the contract ; but no notice was ever taken of this recommendation. 
 I asked the bureau to make a comparative test with any gun made or to 
 be made ; but it was refused. With the charges used in my gun almost 
 every shot broke in the firing ; and there are tons of shot broken in the 
 guns and out of them, weighing from one to ten and twenty pounds. 
 And I venture to say that the guns rejected by the department will 
 stand with equal charges rounds enough to burst 100 guns of any other 
 make the government possessed of equal calibre. These guns now lie 
 in my works, six of them finished, and five of them wanting the rifling 
 put into them to complete them. None of them have been accepted. I 
 refer you to the evidence given before the Committee on the Conduct of 
 the War, in 1864-'65, and the testimony given by Commodore Hitchcock 
 and Commodore T. A. Hunt, on the proof of these guns. No metal can 
 stand the strain and shock of powder in excessive quantity without 
 injury; and my meaning of the contract was that the ordinary powder 
 used (if 20 pounds to the charge) would not burst the guns, and it has 
 not. And I do not believe there has ever been a gun that has stood so 
 much. I am informed and believe that a wrought-iron gun, made by 
 direction of the Navy Department, by Captain Ericsson, at a cost of 
 from $30,000 to $40,000, though it failed completely after 30 rounds, was 
 paid for in full ; also an 80-pounder wrought-iron gun made at Heading, 
 Pennsylvania, though never fired, and worthless, was paid for by the 
 department. A wrought-iron 80-pounder was made at the navy yard. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 11 
 
 at a great cost, never has been fired, and snows unmistakable evidence 
 of its unfitness for service. I have at times called upon the department 
 to continue the firing of these guns with suitable powder and shot, but 
 my request has not been complied with ; and I am refused payment for 
 my guns under the frivolous pretext that they do not answer the terms 
 of the contract. Had these guns been properly rifled and proved with 
 their normal charges, as specified in the contract, no complaint could 
 have been made of their quality. Nor do they now show, after the 
 unparalleled proof they have withstood, any serious fault. 
 
 WASHINGTON, November 11, 1867. 
 THOMAS TAYLOR sworn and examined. 
 By Mr. LOGAN: 
 
 1. Question. I understand from your former testimony that you have 
 had considerable experience in experimental firing of guns at Fortress 
 Monroe! 
 
 Answer. Yes, sir. 
 
 2. Q. Have you any knowledge of the bursting of any Kodrnan guns 
 at that place I 
 
 A. Yes, sir. 
 
 3. Q. Of what calibre were they ! 
 
 A. Two 8-inch burst and one 12-inch. 
 
 4. Q. How many rounds had the 8-inch guns been fired respectively? 
 A. One of 1,500 rounds and the other 50. The 12-inch about 35. 
 
 5. Q. Were uniform intervals allowed to elapse between each round I 
 A. No, sir; we fired them as fast as we could load and fire and prepare 
 
 instruments to take velocities. 
 
 6. Q. About how great a length of time on the average elapsed between 
 each round ? 
 
 A. Perhaps ten minutes ; sometimes it might be half an hour. 
 
 7. Q. Sometimes longer ? 
 
 A. Yes, sir; that arises from the machine sometimes not working 
 well. 
 
 8. Q. After each round you applied certain instruments and made a 
 certain examination of the gun I 
 
 A. No, sir; we have two instruments for taking the initial velocities; 
 one is Schultz's chroinoscope and the other Benton's ballistic pendulum. 
 With these we take the velocities. They sometimes get out of order. 
 
 9. Q. What was the weight of powder used in the 8-inch and 12-inch 
 guns respectively. 
 
 A. Fifteen pounds of rebel powder ; which gives a velocity of about 
 1,250 feet per second. 
 
 10. Q. Do you mean to say rebel powder is better than ours f 
 
 A. We had some powder called rebel (which I suspect was English) 
 which was very good. 
 
 11. Q. I understand you to say a 12-inch gun burst after how many 
 rounds ? 
 
 A. One 12-inch burst after 35 rounds. That is known as the Atwater 
 navy gun. It is a Rodman gun rifled on the Atwater principle. 
 
 12. Q. How long a time was consumed in firing those 35 rounds I 
 A. A good many months maybe six. 
 
 13. Q. Are you aware of any other 12-inch guns that have been made 
 for the army and navy ? 
 
 A. I understand there are two others made for the navy. 
 
12 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 14. Q. Do you know of any other instances where they have burst? 
 A. These burst. There were but three of them made and they burst. 
 
 15. Q. How many rounds were these others fired that burst? 
 A. I believe they all burst under 50 rounds. 
 
 16. Q. What kind of projectiles were fired in them? 
 
 A. The projectiles, I believe, were mixed. Parrott projectiles, I think, 
 were mostly used, but I am not very sure. With regard to the two that 
 were burst by the Navy Department, I have only second-hand informa- 
 tion. The one that burst at Fortress Monroe was served mostly with 
 the Dyer projectile. 
 
 17. Q. Will you explain in what the Atwater system of rifling consists? 
 What its peculiarity ? 
 
 A. It consists in removing one-half the lands out of the gun from the 
 muzzle towards the breach one-half in number and one-half in length. 
 
 18. Q. And the Dyer projectile extends into the grooves ? 
 A. Yes, sir. 
 
 19. Q. In those that were recovered was it found that the soft metal 
 band had expanded, enlarged in the grooves towards the muzzle? 
 
 A. No, sir. 
 
 20. Q. What kind of powder did you use ? 
 A. Generally, I believe, mammoth powder. 
 
 21. Q. The object of using mammoth powder as I am informed is to 
 continue the pressure of the gases against the shot farther towards the 
 muzzle ? 
 
 A. Yes, sir. 
 
 22. Q. And yet the pressure was not sufficient to expand the lead into 
 the grooves when the shot had moved half the length of the gun ? 
 
 A. No, sir; in no case. 
 
 23. Q. What has been the proof of heavy guns, as far as you know, at 
 Fortress Monroe that is, what has been considered the proof of the 
 guns ? 
 
 A. We were firing about 15 pounds, which was the standard charge 
 for 8-inch guns. 
 
 24. Q. How many rounds firing ? 
 A. Do you mean at a time ? 
 
 25. Q. No, I mean the entire proof. 
 
 A. We did not prove in that way. Parrott would fire ten rounds and 
 be done with it, whereas we would fire a thousand if it would stand it. 
 
 26. Q. Has a 12 or 15-inch gun ever to your knowledge been fired 20 
 or 30 rounds in course of proof in as rapid succession as it could be 
 loaded and fired ? 
 
 A. Do you mean rifled ? 
 
 27. Q. Yes, I mean rifled. 
 
 A. A rifled 12-inch gun has been fired in my presence 10 times with 
 double charges in 35J minutes. 
 
 28. Q. Has it ever been fired 20 or 30 times in as rapid succession ? 
 A. No, sir. 
 
 29. Q. Has the 15-inch Eodman gun, to your 'knowledge, ever been 
 fired that number of times in rapid succession ? 
 
 A. It has been fired 10 times with hundred-pound charges in my 
 presence, and I think that is the most rapid that it has been fired. 
 
 30. Q. Do you know any reason why the firing was not continued 
 beyond the 10 rounds as a further test? 
 
 A. I asked the colonel if it would not be well to fire it 20 rounds and 
 get over the assertion of Mr. Wiard that it could not ; and he did not 
 give me any answer. 
 
EXPEEIMENTS ON HEAVY ORDNANCE. 13 
 
 WASHINGTON, November 11, 1867. 
 
 TIMOTHY A. HUNT, commodore United States navy, sworn and ex- 
 amined. 
 
 By the OH AIRMAN pro tern. : 
 
 1. Q. How have you been em ployed for the most part during the war? 
 A. In the fore part of the war I was in the Pacific ocean. Was ordered 
 
 home in 1862, placed on ordnance duty, and have been on that duty since. 
 
 2. Q. Were you a member of the commission to try the Ames gun at 
 Bridgeport in 1864 and in 1866? 
 
 A. Yes, sir. 
 
 3. Q. How many did you try in 1864 and how many in 1866 ? 
 
 A. At Bridgeport we tried one in 1866 for range only, and tried two 
 of the same class at Falls Village in the same year. 
 
 4. Q. Will you state what was the result of those trials ? 
 
 A. The first gun fired in 1864 was a 7-inch bore. It was fired 700 
 rounds with different charges of powder from 19 pounds up to 30 pounds. 
 It stood the test very well. 
 
 5. Q. In making a trial of guns do you use a charge large enough to 
 give the greatest velocity to the shot ? 
 
 A. No, sir; in proving cast-iron guns we use the service charge only, 
 which does not give the greatest velocity 10 rounds of the service 
 charge. The first gun is fired a thousand rounds service charge, and all 
 after that is made as near like the trial gun as possible, and fired with 
 10 rounds. 
 
 6. Q. When you fixed the Ames wrought-iron gun, did you use the 
 service charge ? 
 
 A. No, sir ; I do not know that any service charge had been determined 
 upon for this gun. We used 15 pounds, 25 pounds, and up to 30 pounds 
 of powder. Then we were trying the strength of the gun. 
 
 7. Q. Did you make any calculation to ascertain what should properly 
 be the service charge for a gun of that description and confine your- 
 selves to that ? 
 
 A. No, sir. 
 
 8. Q. Why did you use these different charges I 
 
 A. To see what the gun would stand and how far it would throw 
 shot. 
 
 9.. Q. Were those sized charges selected by the commission themselves 
 or were they used under instructions from the Ordnance Bureau?- 
 
 A. The first was selected by the commission ; General Gillrnore was 
 at the head of that. 
 
 10. Q. Did you use the same sort of charges when the first gun was 
 tried I 
 
 A. That was the one I have reference to, in which we used charges 
 of 25 pounds and 30 pounds. 
 
 11. Q. How was it in 1866 I 
 
 A. That gun was fired merely for the range. 
 
 12. Q. With large charges such as you used in the Ames gun, how 
 many rounds could you fire in a cast-iron gun without destroying it ? 
 
 A. I do not know, sir ; it would not stand so many, I think, as the 
 Ames gun. 
 
 13. Q. Would it stand such charges at all ? 
 A. It might stand a few. 
 
 14. Q. Did you make reports on this subject to the Ordnance Bureau 
 from Falls Village, Connecticut, on the 22d day of February, 1866, and 
 
14 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 from the same place on the 10th of March, 1866, and on the 14th of 
 March, 1866, and on the 24th and 27th of March, the 10th of April, and 
 on the 14th of September, 1866 ! 
 A. Yes, sir ; those are all my reports. 
 
 15. Q. Besides these official reports made by you, have you written 
 any unofficial communications to the chief of that bureau upon the sub- 
 ject of these guns f 
 
 A. Yes, sir ; I made some, but of the same tenor as the official reports ; 
 and those private reports I find are also on file. 
 
 16. Q. Do you remember to have said anything about the quality of these 
 guns more fully in your private communications than in the official 
 report I 
 
 A. No, sir ; I do not know that I did. 
 
 17. Q. What was the kind of powder used in your proof of these 
 guns? 
 
 A. I think the powder we used at Bridgeport was No. 7 Hazard's 
 powder, with initial velocity 1,440 or 1,450 feet. 
 
 18. Q. Was it a quick-burning, fulminate powder, more likely to burst 
 a gun than that ordinarily used in the service charge ? 
 
 A. No, sir j I think not. It was such powder as we put on ship-board. 
 It was sent from New York magazine, from the same lot out of which 
 we got powder to put on ship -board for service. 
 
 19. Q. Did the shot break in the gun or outside of it in these trials ? 
 A. Not in the trial at Bridgeport. I fired two guns afterwards at 
 
 Falls Village. We fired it 220 rounds with 20 pounds each charge, and 
 shot weighing 100 pounds, and five, I think, of 10-pound charges, and 
 10 of 15 pounds ; making 235 charges. 
 
 20. Q. With what result? 
 
 A. The gun was very much enlarged in the bore in the rear of the 
 shot. Eight in the centre of the bottom of the bore there was a depres- 
 sion commenced after firing 15 or 20 rounds ; and that depression kept 
 eating in to the depth of four inches. 
 
 21. Q. How large was that orifice in circumference I 
 A. Large enough to insert the little finger. 
 
 22. Q. To what did you attribute that ? 
 
 A. The pressure of the powder ; and owing to the sulphur in the pow- 
 der, when any abrasion takes place in cast-iron, and the powder once 
 gets hold of it, it eats in very fast. 
 
 23. Q. Then it is not to be accounted for entirely by the pressure, but 
 by the corrosive character of the gases. 
 
 A. The pressure in the first place dents it in, but when the corrosive 
 quality of the gas once gets hold of wrought iron it eats in very fast. 
 There were some other defects in the chamber of that gun, but the bore 
 was in very good condition, according to the charge of powder. 
 
 24. Q. What was your general conclusion in your report and the con- 
 clusion you arrived at in your mind as to the value of these guns. 
 
 A. The wrought-iron guns I consider the strongest guns that can be 
 made ; stronger than any we have, provided the welds are secure. There 
 is no doubt that gun at Bridgeport stood remarkably well longer than 
 any cast-iron gun we have in the service. I think the last two guns 
 that I fired also stood charges of powder that cast-iron guns would not 
 stand. 
 
 25. Q. How would it have been in active service if these guns had 
 been used with a proper service charge j do you consider they would 
 have been effective guns I 
 
 A. I do not think they would have enlarged or that these depressions 
 
EXPERIMENTS ON HEAVY ORDNANCE. 15 
 
 would have occurred, if they had been fired with less charges. I think 
 this 6 T 4 Q~inch gun will not stand successive charges of 20 pounds of pow- 
 der and 100-pound shot. 
 
 26. Q. Is it your opinion, then, that if these guns of Mr. Ames had 
 been used in active service with a proportionate service charge of pow- 
 der only, they would have proved effective and useful guns I 
 
 A. It is very probable, sir. 
 
 27. Q. Is it the practice, or has it been for many years, of the Navy 
 Department to test guns with more than the service charge ? 
 
 A. No, sir; I have proved a great many guns, and have always proved 
 them with the service charge. After the guns are offered for proof we 
 fire them with 10 rounds service charge. 
 
 28. Q. The reason then for increasing the charge in the trial of these 
 guns was because it was a gun of new manufacture I 
 
 A. Yes, sir ; something new ; some doubt as to the weld of the gun. 
 
 29. Q. And it was not the ordinary trial of a navy gun ! 
 A. No, sir ; something new. 
 
 30. Q. Did you answer in regard to the breaking of shot f 
 
 A. No shot were broken in the gun j but the bands would fly off after 
 leaving the gun, but the most of them broke on striking the bank into 
 which they were fired. 
 
 31. Q. Were those shells with soft metal bands at the base of the 
 shell ! 
 
 A. Yes, sir; composition. 
 
 32. Q. Have you ever known what, in your opinion, was a better or 
 stronger gun in our service than this Ames gun, as you would judge 
 from that trial of them f 
 
 A. I have never known any gun to stand the test that 7-inch gun 
 stood, and also the one that was fired at Falls Tillage. The second gun 
 fired at Bridgeport was fired only 45 times ; that was not much of a test, 
 it was merely fired so as to get the range. 
 
 33. Q. I asked if you know of any better or stronger gun in our service. 
 A. I say the first gun was the strongest and stood the best test of any 
 
 gun I have known in our service ; but I cannot say as to the last, for 
 that was only fired 45 times, and simply to secure the range. 
 
 34. Q. Suppose you were in a fight with an enemy, would you or not 
 like to trust to these guns such as you tried there ? 
 
 A. It is a new gun, and there is some doubt, as I said before, about 
 the welding. If the gun is perfectly welded there is no stronger gun 
 made. But we have to run some risk with all guns, cast iron as well as 
 wrought iron, and the wrought iron being a new gun there is some doubt 
 about it. There is no doubt the wrought-iron gun would stand remark- 
 ably well with a charge of 10 pounds or 12 pounds of powder. 
 
 35. Q. If you can get a good gun that will give a greater velocity 
 to the shot than any other having more strength to stand the charge, is 
 not that gun proportionately more valuable for war purposes f 
 
 A. Certainly, sir. 
 
 36. Q. Will any cast-iron rifled gun in your opinion stand the shock 
 of a charge that would give 1,500 feet velocity per second ? 
 
 A. It might for some few charges, but I think not for any consecutive 
 number of charges. 
 
 Is not a wrought-iron gun of this kind strong enough to give that or 
 a greater velocity if you can depend on the safety of the gun ? 
 
 Yes, sir; I think that these guns cannot be bursted expansively. If 
 they burst anywhere it would be the weld fly off in the rear. 
 
 Did any Ames guns out of those you proved burst f 
 
16 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 No, Sir. 
 
 What defects did you observe developed in the trial of the gun besides 
 this orifice or cavity that was produced at the bottom of the bore ? 
 
 There were some few around in the circle of the bore. A crack or 
 cavity went nearly round the gun, and that kept eating in as we fired. 
 
 Was it at a line where the weldiDg took place I 
 
 I should think not ; it was in the chamber of the gun, that is in the 
 bottom of the bore. 
 
 What was your conclusion in regard to the principle upon which Mr. 
 Ames has been manufacturing these wrought-iron guns ? 
 
 I think his principle is the best we know of at the present day ; think 
 it will make the best gun. I think it is a much safer way than welding 
 them in coils as the Armstrong and other guns are made . 
 
 37. Q. Do you know how that process is accomplished by Mr. Ames ? 
 A. Yes, sir; there are three rings concentric rings. The lower one 
 
 projects a little and the next one a little more : so that when the two 
 parts are brought together to be welded, these rings are about six inches 
 in depth, and as they are brought together the middle takes first as the 
 welding goes on, and the outside ring takes last, with the object of let- 
 ting off the scoriae produced by the oxidation of the iron, so as to have 
 a clean weld ; and if you can keep clear of all these cinders and the ex- 
 coriation which takes place as soon as the iron is brought to the atmos- 
 phere, you can make a perfect weld of it. 
 
 38. Q. Was your attention directed to the rifling of these guns ? 
 
 A. The rifling of the guns was a regular twist one turn to 60 feet. 
 That was the rifling of the gun which I fired for Mr. Ames at Bridgeport, 
 in 1865, which in my opinion was no test for any other gun. I do not 
 think there is any comparison to be made with that and any other gun. 
 For that reason I fired it but 45 rounds. 
 
 39. Q. That twist was selected and ordered by the Ordnance Bureau? 
 A. Yes, sir. 
 
 40. Q. Do you know whether Mr. Ames himself objected to that rifling? 
 A. I do not know, sir. When I saw the result I thought it bad rifling 
 
 to give long range that there was not rotary motion enough for the 
 shot. Before the force of the shot was expended, the rotary motion was 
 done and of course the shot would not go as far. 
 
 41. Q. What rifling would you prefer for a gun of large calibre like 
 that one which would commence with a slow turn and quicken as it- 
 approached the muzzle, or would you have uniform rifling ? 
 
 A. There is a difference of opinion about that. 
 
 42. Q. I know there is, and that is the reason why I ask you the ques- 
 tion. 
 
 A. We know very little about the rifling of guns. My idea is that we 
 should get a number of guns of the same calibre, and rifle them all dif- 
 ferently, and fire them with the same powder and at the same time, and 
 see which gives the greatest range and velocity ; and that until that is 
 done we shall reach no satisfactory conclusion. 
 
 43. Q. Do you know whether there ever has been such an experiment 
 or series of experiments in order to test the value of differently propor- 
 tioned rifling of guns, by either the army or navy ? 
 
 A. There were some experiments made by the navy of Parrott's rifling, 
 At water's rifling, and, I think, Rodman's or some other, and it was con- 
 sidered that Atwater's rifling was the best, gave the best results. 
 
 44. Q. What is the peculiarity of that rifling J ? 
 
 A. It is that after the shot gets started he cuts away the grooves so 
 that there is not so much friction half way down the gun. The lands 
 
EXPERIMENTS ON HEAVY ORDNANCE. 17 
 
 were cut half way out and made smaller so as to prevent so much fric- 
 tion and cause the rotary motion. 
 
 45. Q. Do you know whether any experiments have been tried with 
 guns precisely similar in calibre, length and construction in every re- 
 spect except the diiference of the twist in rifling, and the difference in 
 result between an uniform rifling and a rifling commencing slowly and 
 increasing ? 
 
 A. No, sir $ I do not know the experiment of that kind that has been 
 made. They may theorize as much as they please about gunpowder, 
 they never can come to any conclusion except by practical tests. 
 
 46. Q. Do you believe the velocity of shot and the range of guns can 
 be calculated with mathematical accuracy, when you have the calibre, 
 the weight of the shot, the charge of powder and the shape of the shot 
 all given ? Or do you think it is necessary to add experience to these 
 conclusions ? 
 
 A. There must be experience added to them. If everything could be 
 made exactly alike, they might do it, but there are so many variations 
 in the i>owder, shot, guns, and conditions, that it cannot be carried out 
 to a mathematical point. 
 
 WASHINGTON, November 11, 1867. 
 E. B. HITCHCOCK sworn and examined. 
 By the CHAIRMAN pro tern : 
 
 1. Question. Will you state in what service you are, and your rank'? 
 Answer. I am commodore in the United States navy. 
 
 2. Q. What is the ordinary proof to which smooth-bore or rifled guns 
 in the naval service are subjected? 
 
 A. In making a contract or engagement for any special class of guns 
 they take the first of that class and submit it to what is ternied extra- 
 ordinary proof, that is, a thousand rounds of service charge. The others 
 are supposed to be duplicates of that gun. They are submitted to 10 
 charges of service rounds. 
 
 3. Q. You take one gun of a class ? 
 
 A. Yes. For instance, if you were going to make 9-inch guns you 
 would take the first and submit that to the extraordinary proof of 1,000 
 rounds. 
 
 4. Q. The extreme proof is 1,000 rounds f 
 
 A. That is the initiatory proof of a class of guns. The others are 
 supposed to be duplicates, and before reception in the service they are 
 fired 10 rounds. 
 
 5. Q. What is the extreme proof to which you subject such guns in 
 the navy, as it regards the charge of powder and its kind! 
 
 A. We have no proof for powder or shot in the ordnance for proving 
 guns. The proof of powder is a thing by itself. 
 
 6. Q. But what is the extreme proof as it regards the size of the charge? 
 A. That depends on whether it is a smooth-bore or rifled gun. 
 
 7. Q. What is the extreme proof to which you subject a smooth-bore 
 gun, as it regards the size of the charge and shot used? 
 
 A. We use the service charge all the way through for any kind of 
 proof 5 and our service charges for smooth-bore guns have varied, gene- 
 erally to one-fourth and one-eighth, with permission to use one-third in 
 service on some occasions. During this last war there were special pro- 
 visions made for going far beyond that. It was restricted at the com- 
 mencement of the war particularly to certain charges. Daring the war 
 experiments indicated that it might be increased with safety, and per- 
 mission was given to increase. 
 Eep. No. 266 2 
 
18 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 8. Q. How is it with regard to rifled guns? 
 A. One-tenth is the service charge. 
 
 9. Q. Then your test iu the navy is one made rather by the number of 
 discharges? 
 
 A. The durability of the gun. ^Looking to the life of the gun," as 
 we sometimes call it in service. 
 
 10. Q. What is considered the measure of the life of a gun in the naval 
 service. 
 
 A. About 800 discharges. Not but what it will stand more than that, 
 but we look for about 800. The Ordnance Office has withdrawn them 
 at 500. But we think when a gun has been fired 800 rounds it ought to 
 be withdrawn. 
 
 11. Q. Your rule is generally that you test guns by the number of 
 rounds you fire. 
 
 A. Yes, sir. 
 
 12. Q. You fire a number of rounds with the service charge? 
 A. Yes, sir. 
 
 13. Q. And if the first gun of a class stands a thousand rounds you 
 are ready to accept the others always upon the ordinary test of 10 rounds'? 
 
 A. Yes ; ten rounds always ; those numbers are fixed. 
 
 14. Q. What is the lowest tensile strength of iron permitted to be 
 used for guns in the navy, and does it differ in those of different cali- 
 bres? 
 
 A. The tensile strength is a thing that was at one time insisted upon 
 with great uniformity and great confidence. We thought we might rely 
 upon it. Afterwards we became doubtful whether it Avas an indication 
 of that importance we had supposed it to be, and of late it has not been 
 insisted upon ; so that I can hardly say. It has been named, you will 
 find in reports, when a contract has been made, that there has been a 
 certain tensile strength; and afterwards orders have been given where 
 it has not been insisted upon from doubts arising in relation to its being 
 so reliable an indicator as it was once supposed to be. When Major 
 Wade made his experiments, followed up by Mr. Mordecai, we supposed 
 we had an infallible guide. I think now they have more confidence in 
 it in the army than we have in the navy. We tried the tensile strength 
 of iron at all the navy yards. We have specimens of the guns, but we 
 do not think it so infallible a test as we formerly did. 
 
 15. Q. Do you recollect what was the rule ordinarily observed in the 
 navy in relation to iron, as to the highest and lowest degrees of tensile 
 strength ? what were the two extremes ? 
 
 A. I do not recollect, sir; but it is a matter of record in any of the 
 text- books, either army or navy. 
 
 16. Q. Did you approve two of these wrought-iron rifled guns that 
 were constructed by Mr. Horatio Ames I 
 
 A. We fired them under orders, but not with a view of experiment at 
 all. Definite orders were given me, which I carried out. I had no voli- 
 tion in changing anything at all. It was not an experiment that I was 
 sent there to use judgment upon, but simply to carry out orders. My 
 duties were prescribed. 
 
 17. Q. Instead of your being detailed, then, to experiment and report 
 your judgment of the guns, you were detailed to perform a specific duty ? 
 
 A. Yes, sir ; and to report the result as facts. 
 
 18. Q. How many charges did you fire, and what was the weight of 
 powder and shot ? 
 
 A. I will have to ask your indulgence to refer to the written report. 
 There is .a written report of all these details. In .the last twenty years 
 
EXPERIMENTS ON HEAVY ORDNANCE. 19 
 
 sir, these things are so much mixed up in my mind that I may uninten- 
 tionally make a wrong statement. 
 
 19. Q.. In the reports that you made to the Ordnance Bureau of the 
 Navy Department, on the 12th day of August, 1865, and on the 4th day 
 of September of the same year, from the West Point foundry, in relation 
 to your trial of the Ames guns, did you confine yourself to just that trial 
 which you had been ordered to make without exercising any discretion 
 of your own ? 
 
 A. Strictly so ; the orders were definite and strictly complied with. 
 
 20. Q. Will you tell me whether that is the usual number and amount 
 of charges used in proving guns of that calibre. 
 
 A. I should say no, sir ; so far as my experience goes. The bureau 
 gives orders for a trial. If they do not prescribe differently it would be 
 10 ordinary service charges. They did not assign to this gun what the 
 service charge should be. If it had been a gun that had been in the 
 service, it would have had its charges assigned. We would simply have 
 been ordered to prove this gun and to use these charges. 
 
 21. Q. If you had been directed at your discretion to make that trial, 
 would you not in the first place have made the trial with the ordinary 
 service charge ? 
 
 A. In former times, when we proved guns, we used excessive charges 
 some two or three rounds, but very excessive. We put in a number of 
 projectiles in the guns smooth-bore guns. When I was first detailed 
 for ordnance duty, that was the practice. I was very much opposed to 
 it, although it is twenty years ago ; and in long conversations with Com- 
 modore Warrington, then chief of the bureau, I think I influenced him 
 to change the order and use the service charges. If I were going to 
 have service charges of two or three different weights of powder, I would 
 always commence with a new gun on the lowest charges. 
 
 22. Q. If the trial had been left to your discretion, you would have 
 gone on testing with charges, and endeavoring, in a new gun, different 
 from any former one, to ascertain what would have been the proper ser- 
 vice charge to be settled for that gun ? 
 
 A. We would ascertain what would be the proper charge. 
 
 23. Q. You would have calculated what would be the proper service 
 charge for that gun and have made your trial from that f 
 
 A. Yes, certainly ; and if practical experience confirmed the theory, 
 we would have held to it. 
 
 24. Q. The trial made with this gun was made with excessive charges 
 rather with a view to see whether you could burst the gun, to ascertain 
 what its duration would be ? 
 
 A. No,, sir; that was not my impression. They commenced by using 
 10 pounds charge and increased it to 15- pounds and 20 pounds to see 
 what the effect would be, not to rupture the gun ; to see what the effect 
 would be on wrought iron cooled in the manner that was. I suppose 
 they wanted so see what the effect of 10 pounds would be, and then in 
 increasing it to see if it produced any other effect on the wrought iron. 
 
 25. Q. Beside your report made after the trial in each case, did you 
 write any unofficial letters to the bureau advising them on the subject? 
 
 A. I cannot say whether I did or did not, sir. We were in the habit 
 of writing unofficial letters to the bureau. I have written a great many 
 unofficial notes, but we were very much pressed at that time in relation 
 to our work, and I should be disposed to say I did not. But I cannot 
 say I did or did not. I have no recollection of doing it. 
 
 26. Q. Do you know of any shot that were broken in or out of the gun 
 in this firing ? 
 
20 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 A. I do fiot remember any of them being broken there. I would 
 rather rely upon the report in regard to that. I do not think any of 
 them were broken there, sir. 
 
 27. Q. Did you use the same powder in firing these guns you did in 
 firing the Parrott guns ? 
 
 A. With one exception I have never used any but service powder. 
 The powder for these guns was ordered from New York, just as any pow- 
 der for proof is ordered. It was not a selection of powder. 
 
 28. Q. In these trials of the Ames guns at West Point foundry, you 
 used the same powder as you used in other trials f 
 
 A. Yes, sir ; used the ordinary service powder. 
 
 29. Q. It was not, then, a quick-burning, fulminate powder? 
 
 t A. It was either to be cannon or No. 7 powder, and the initial velocity 
 was to be 1,500 feet for one and so much for the other. Those standards 
 are laid down in the ordnance instructions. 
 
 30. Q. Did you use what is called the water-proof of guns there some- 
 times*'? and if so describe how you apply the water. 
 
 A. It is a hydraulic pump of very small construction capable of rais- 
 ing a weight of two atmospheres, merely pressure enough to force the 
 water into any cavity that may exist. It produces no strain. 
 
 31. Q. Did you put either of these guns through that water-proof? 
 A. Yes, sir ; I did. 
 
 32. Q. With what effect? 
 
 A. There is no effect produced by that unless there is some little cavity 
 which will retain the moisture longer than other parts. 
 
 33. Q. If a gun is remarkably porous $he water sometimes conies 
 through? 
 
 A. -I have seen it come through wrought-iron guns. 
 
 34. Q. Would the degree of pressure to which you submitted one or 
 both of these guns in that water-proof have burst a cast-iron gun ? 
 
 A. No $ it is only two atmosphere. It is not used with that idea. The 
 object is simply to find whether there are any little cavities. I never 
 have used this pressure of two atmospheres with an idea I was going to 
 develop anything further than letting the water get into some porous 
 place. We are not at liberty to increase the hydraulic pressure. We 
 are confined to two atmospheres. 
 
 35. Q. Did you ever fire any charges in a Parrott gun of the same 
 calibre as large as the largest you fired in this Ames gun ? 
 
 A. Yes, sir ; but I was confined to certain instructions. I have tried 
 experiments with Parrottfs guns, but not under orders from the ordnance 
 bureau. They were experiments being tried with guns where the navy 
 had nothing to do with it. 
 
 36. What was the effect of the 20 pounds charge on the Parrott gun? 
 A. There was no injury to the gun in that instance. 
 
 37. Q. What is the service charge now in a Parrott 100-pounder ? 
 A. Ten pounds. 
 
 38. Q. Is that regarded as charge enough to give the highest velocity 
 to the shot? 
 
 A. They settled on the ten pounds as a mean, as being the best in the 
 long run both for wear of the gun and for safety and for many other con- 
 siderations. Certainly a higher velocity might be obtained with more 
 powder. 
 
 39. Q. Would you consider that gun a good gun that would not stand 
 charge enough to give the highest velocity to the shot ? 
 
 A. Yes, sir ; but I would consider the gun that would give the greatest 
 velocity the better gun. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 21 
 
 40. Q. Would you considerthat a good gun that would not stand charge 
 enough to give the highest velocity ? 
 
 A. Yes, sir ; I would consider such a gun a good serviceable gun, yet 
 not the best ; because the best would be one that would combine all the 
 advantages. 
 
 41. Q. Do you know the Dahlgreii shell gun ? 
 
 A. I know it, but not enough to give answers in relation to it. 
 
 42. Q. Do you know whether that gun will stand a heavy enough 
 charge of powder to give the highest velocity to the shot? 
 
 A. Some of them would not. I think there is a great difference in 
 those guns. I think the 50-pounder was a very good gun, and all the 
 large ones perfectly worthless, because they would not stand. 
 
 43. Q. Do you know any gun that will stand any considerable number 
 of rounds, yet giving the highest velocity to the shot ? 
 
 A. I do not believe they exist anywhere, sir. 1 do not believe any 
 such gun has yet been produced. Not any large number of rounds. I 
 think there are guns that will afford the highest velocity powder can 
 give for a few rounds. 
 
 44. Q. After the experience at Fort Fisher, was the service charge for 
 the 100-pounder Parrott gun reduced? 
 
 A. I am not quite positive about that; I wasoii board, too, in relation 
 to that charge. I am rather under the impression it was, and I think I 
 voted against .it. That is a matter of record. 
 
 45. Q. Is not the service charge of the Parrott gun now eight pounds ? 
 A. I think it is reduced down to eight pounds. 
 
 46. Q. You have been inspecting these Parrott guns for years, have 
 you not? 
 
 A. Not for the last two or three years. I was employed a number of 
 years inspecting them. I inspected the first guns the navy ever took 
 and the last they took, and all between, with exception of one year's. 
 
 47. Q. What was the cause of some of the Parrott guns being bored 
 out of centre ? 
 
 A. From not duly watching the machine. It is somewhat difficult 
 after a gun is bored to determine whether the bore is precisely in the 
 centre, and the demand was so urgent that some were sent out without 
 having been properly tested. 
 
 48. Q. You attribute the fact of any guns having gone out which, from 
 defect of machinery, were not bored perfectly in the centre, to the haste 
 of producing guns required at that time ? 
 
 A. I think that was the reason. 
 
 49. Q. Can you throw a shot from a Parrott 100-pounder as far with 
 8 pounds or 10 pounds of powder as you could with 15 or 20 pounds f 
 
 A. Certainly not, sir. 
 
 50. Q. Are you acquainted with the English wrought-iron steel gun 
 particularly the Armstrong gun ? 
 
 A. No, sir ; only from general Information. 
 
 51. Q. Do you know the quantity of powder used for the charge of the 
 different calibres of those guns ? 
 
 A. I have seen it stated, sir, from time to time. They have charged 
 the amount of powder in those guns repeatedly. They have advanced 
 and receded. The first guns put on their naval ships was at a very low 
 rate. They then increased them, and again reduced them. I knew of 
 the firing of the first Armstrong gun made in the United State made 
 by Mr. Parrott made for the Russian government, sir. W^hen it was 
 supposed to be a secret in England the Russian government obtained 
 by some means the plan of the Armstrong gun and brought it to Parrott 
 
22 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 and lie made one of the guns ; and strange to say, the best of ranges that 
 have ever been obtained by Armstrong's guns were obtained by the one 
 made by Parrott accidental, undoubtedly. 
 
 52. Q. Has there not been some understanding that an American 
 inventor, even before Armstrong's time, produced a gun of that kind 
 and exhibited it to the navy bureau? 
 
 A. Do you mean Professor TreadwelPs gun ? 
 
 53. Q. I do now know whose it was. 
 
 A. There is a gun a great deal like Armstrong's gun, but the name of 
 the inventor has escaped me. I fired the gun for him here. 
 
 54. Q. How long ago was that ? 
 
 A. That was 15 or 18 years ago. Chambers's gun, ihe first one he got 
 up, was a good deal like the Armstrong gun. 
 
 55. Q. That was before the Armstrong invention came out? 
 
 A. Yes, sir; before we knew anything about it. The guns did not 
 look alike, but the principle was very much the same. 
 
 56. Q. For what purpose did you use an SO-pound shot in a 100-pounder 
 gun? 
 
 A. The shot was used for penetration, sir ; to determine its power of 
 penetration. 
 
 57. Q. Will you explain the common twist of the rifling used in the 
 Parrott gun ? 
 
 A. It is an increasing twist begins slowly and increases in curve 
 towards the muzzle. 
 
 58. Q. Do you think that is the best twist for a 100-pounder? 
 
 A. It depends on the projectile that is used, how the projectile takes 
 the twist. I think it is the best one with the projectile that is caused to 
 take the groove by the band. 
 
 59. Q. What is the twist of tl^e Ames gun? 
 
 A. Two twists one of Mr. Parrottfs and one of what we call Brooks's. 
 
 60. Q. One was a 60-foot twist? 
 A. That was the Brooks. 
 
 61. Q. A very slow twist, was it not? 
 A. Yes, sir. 
 
 62. Q. What do you think of that 60-foot twist? 
 
 A. I do not like it, sir, for the projectiles we use. Do not think you 
 get as great an effect. 
 
 63. Q. Do you get as long a range ? 
 
 A. I do not think you do. I think, as I said before, thu ^arrott twist 
 is the best adapted to the expansibility of the ring. 
 
 64. Q. Do they fire larger charges in the Armstrong or English wrought- 
 iroii guns than in the rifled guns we have in this country ? 
 
 A. Of my own knowledge the last of the Armstrong guns they had at 
 sea was fired first with one-tenth ; they then came down to one- twelfth, 
 having, in their experiments, gone to very high charges. 
 
 65. Q. Who is Brooks, and how came that rifling? 
 
 A. He once belonged to our navy. I am sorry to say the last I heard 
 of him he was fighting against us. Mr. Brooks is a man of a good deal* 
 of cleverness. He got his first reputation from, a sounding apparatus 
 when he belonged to the Coast Survey. I do not fancy his rifling. How- 
 ever, that is a matter of mere opinion. He does. 
 
 66. Q. What are the velocity and range of a Parrott 100-pounder gun 
 charged with eight pounds of powder ? 
 
 A. That I cannot say, sir. They have, I think, about 1,200 feet with 
 10 pounds of powder. 
 
 67. Q. Since the reduction of the charge, do you know of any experi- 
 ments to determine the range? 
 
EXPERIMENTS ON HEAVY ORDNANCE. 23 
 
 A. I never saw an 8-pound charge fired out of one of these guns, and 
 I have seen thousands upon thousands of the others. 
 
 68. Q. You think that gun should and would stand 10 pounds! 
 
 A. I ought to think so, sir, when I have seen 20,000 or 30,000 rounds 
 fired with them. I simply base my opinion on that. 
 
 69. Q. What is your estimate of the difference in value between a gun 
 that must be fired with eight pounds of powder and one that would 
 stand firing with 15 or 20 pounds. 
 
 A. It would be just in an inverse ratio to this amount. The gun that 
 would stand the heaviest charge would be the most valuable. Run it 
 down to the gun that would not stand powder enough to throw the ball 
 out, and its value would be represented by a 0. 
 
 70. Q. Do you know of any gun that has yet been produced stronger 
 than the experiment would lead you to think this Ames gun might be 
 in use ? 
 
 A. My ideas may be very peculiar. I was called upon to look at Mr. 
 Ames's effort when he first commenced his first gun. I was delighted to 
 see he had struck out on what I thought was dangerous business, to work 
 wrought iron, and hoped every success might attend his effort, knowing 
 perfectly well that was the siJfongest form iron could be presented in if 
 true iron all the way through. The only difficulty in my mind was 
 making it perfect. I doubted if he was able to make a gun with perfect 
 certainty. He made a gun, and, as Colonel Laidley has just testified, 
 and the report shows, it was fired at Bridgeport, and endured remark- 
 ably ; but the question was, with the intention of making* the next gun 
 identically the same, whether he would be successful, or could be assured 
 it was the same. They tried another gun and found it was not. That 
 was just my fear of the danger of working wrought iron. You might 
 cut open ten guns in succession, every one being perfect, but I am not 
 certain the eleventh would be. I am not a mechanic, but I have watched 
 them at their work a great deal, and I find them very frequently making 
 mistakes in heavy welds. The high heat certainly oxidizes iron very 
 frequently. That oxide interposes itself between the true iron. I think 
 I have seen that in one of Mr. Ames's guns. 
 
 71. Q. Your idea then is this, that in making cast-iron guns there may 
 be such uniformity in the character of the material employed that you 
 can safely trust to a class of guns when one of that class stands the 
 required test I 
 
 A. Yes, sir. 
 
 72. Q. But in the case of wrought-iron guns you could obtain satisfac- 
 tion only by the testing of each particular gun ? 
 
 A. Yes, sir. I think in the present art of working iron there has been 
 greater uniformity with cast than with wrought iron in large masses. 
 They make gun-barrels of wrought iron with great success. The time 
 may come when they may work wrought iron with like success in large 
 quantities 5 but they have not done it yet in France, England, or the 
 United States, that I have seen. Nobody doubts that wrougfit iron is 
 stronger than cast. There is a great difference in the effects on the 
 metal inside. Cast iron is less injured by the action of the interior of 
 the gun than any metal I have ever seen ; and steel one of the most easily 
 injured. 
 
 73. Q. Is that owing more to the concussion or pressure, or to the cor- 
 roding effect of the gases produced by combustion ? 
 
 A. I think it is the absence of the junction of true iron. Wrought 
 iron almost always assumes a laminar form $ arid between these leaves, 
 as it were, a foreign substance seems to interpose which the gas acts 
 
24 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 upon. In this examination of Mr. Ames's guns he was not present, being 
 absent in Europe. In examining the interior of the gun, we took a small 
 piece of steel and bent it at right angles, bringing it down to a cutting 
 point less than ^-inch in width. We put it on a light handle and drew 
 it through the grooves of the gun. This would find a little resting place, 
 but when you looked at it it looked like a mirror. We could see that it 
 was not an imperfect weld this was catching, but on the iron itself in its 
 laminar form. When we came to fire it this became very apparent. 
 
 74. Q. Was this observation made before or after the firing I 
 
 A. Before an.d after each fire, sir. Impressions were taken of the 
 whole interior of that gun, and I presume are now in the ordnance 
 department. 
 
 75. Q. Was that lamination increased much by the firing ? 
 
 A. O, very much, sir j very much. I have seen larger defects than 
 that in a cast-iron gun, and the gun stand 1,400 or 1,500 rounds. 
 
 76. Q. Have you come to the conclusion that a wrought-iron gun can- 
 not be made of large calibre perfect enough to be used and adopted 
 safely in practice I 
 
 A. I think you can make the strongest^un we know out of wrought 
 iron. I think there would be a perfect uncertainty in relation to the 
 guns. One of them will stand ; another will not. I think they would 
 be a fa dangerous class of guns until they know more than I think they 
 know now. 
 
 77. Q. How do you account for the bursting of those Parrott guns at 
 Charleston and Fort Fisher ? 
 
 A. I think it occurred from various causes, sir. You never can make 
 a large number of guns out of any material, wrought iron or cast iron, 
 but you will have some guns that have inherent weakness. Some of 
 those guns may have exploded from that cause. My theory has been 
 that the greatest injury came from the projectiles. 
 
 78. Q. You attribute, then, the bursting of so many of those guns 
 rather to the projectiles that were used ? 
 
 A. The majority of them were found to have the projectile burst in 
 them, and, of the remaining part, there was no record to show whether 
 the facts were the same or not. 
 
 79. Q. Was not that the difficulty with regard to a great proportion 
 of thos that burst a want of data ? 
 
 A. Thsre was a very great want ; but in a great many instances there 
 was information. A remarkable thing took place there. An officer, 
 Captain Temple, came up to West Point to see the firing that was going 
 on, and pick up some little ideas in relation to ordnance. I tried to 
 impress upon him that there was a great necessity of using grease not 
 to lubricate the shell, but to burn grease in the gun at every discharge ; 
 and also that the coating of the shells inside should be strictly attended 
 to to prevent premature explosion of the shell. He took command of a 
 vessel and went down there. He attended to both my suggestions, and 
 did not have a premature explosion of a single shell; was the only vessel 
 that escaped it"; nor did he have a gun injured. 
 
 80. Q. What was his vessel ? 
 A. I do not recollect the name. 
 
 81. Q. Was that at Fort Fisher or Charleston? 
 
 A. Fort Fisher. I can state another thing: in firing these elongated 
 projectiles, where there is a great deal of powder in the interior of the 
 shell, I fired some to try and find out what was the cause, if I possibly 
 could, of so many shells bursting prematurely. I plugged up the shell 
 and fired a number of them over at the bank across the Hudson. I 
 
EXPERIMENTS ON HEAVY ORDNANCE. 25 
 
 recovered the shell and cut them open. The powder inside was caked so 
 hard that, in cutting through it, it polished like a piece of slate. 
 
 82. Q. Did you ever in your trial of guns burst a gun by bursting the 
 projectile in the gun f 
 
 A. No, sir ; not entirely to rupture the gun, but to an indentation very 
 deep, and only wonderful the gun should not have yielded. 
 
 83. Q. Do you believe a gun could be injured by the bursting of a pro- 
 jectile in the gun without deep indentation on the interior surface of the 
 bore f 
 
 A. Yes, sir ; I have seen a gun that has been burst where the whole 
 bore of the gun has been swelled outward, and there was strong evidence 
 that the gun burst from its obstruction. 
 
 84. Q. Then you would, in every case, expect deep indentation, or 
 forcing out of true line the bore of the gun, if a projectile exploded in the 
 gun! 
 
 A. Not necessarily. The most natural thing would be that the gun 
 would be spread there, yet it is possible to take place and not do it. 
 
 85. Q. Is there any prevailing character of fracture you ever discov- 
 ered in the bursting of these Parrott guns, whether up next the band 
 or at the muzzle f 
 
 A. I do not know that 1 could say there is any prevailing character. 
 My observation would go to say rather that they had yielded from the 
 vent-hole. The first crack in the metal comes from the rear of the vent 
 as a general thing. 
 
 86. Q. Do not they appear to have fractured in all kinds of ways f 
 
 A. Yes, sir. The first indication you find of any yielding in a gun I 
 do not mean where you explode shells, but the wearing out of the gun 
 is the crack that takes place there. I have seen that in hundreds of 
 instances. 
 
 87. Q. What you mean then is, that in long use of a gun the first place 
 at which there is indicated a giving way of the gun is generally there at 
 the vent ? 
 
 A. It is across, at right angles to the bore ; whereas in smooth-bore 
 guns the line of the first fracture is forward of the vent. The English 
 and French say the same in relation to theirs. 
 
 88. Q. Did you fire a 50-potmder gun, made of semi-steel by Mr. Wiard, 
 up to extreme proof ? 
 
 A. I fired a gun that Mr. Wiard had made as a contractor. My 
 impression is that that gun was not fired up to 1,000 rounds, but between 
 400 and 500, sir; near 500. This was in 1861. It was the first gun of 
 that kind fired at Staten Island. 
 
 89. Q. Did you find that gun deteriorate under these experiments ? 
 A. It stood remarkably well. 
 
 90. Q. Did you afterwards fire other guns of the same kind a less num- 
 ber of rounds, and if so, with what result *? 
 
 A. Yes, sir ; part of them burst. One of those that burst had a false 
 chamber introduced into it. It was on that account that objection was 
 raised to the guns I raised it myself that there was* an attempt -to 
 defraud in making the guns, and therefore tlilre was nothing produced 
 by the makers that should be received for a moment. I stated, as I then 
 believed, that Mr. Wiard knew nothing of it ; but I did not look upon 
 him as the maker of the gun ; he was the contractor and got these guns 
 made. 
 
 91. Q. This, if I understand you, confirms your idea that in the case 
 of a steel or wrought-irou gun there is no safety without a trial of each 
 particular gun. Are these guns that were fired and burst at ten rounds 
 similar to that which stood the 480 rounds ? 
 
26 EXPERIMENTS ON HEAVY ORDNANCE, 
 
 A. Yes. I say in the report that I supposed at that time that Mr. 
 Wiard had no knowledge of that deception ; that only exonerates Mr. 
 Wiard as a contractor. They made a gun that had too long a bore. 
 They wanted to shorten that, and inserted a piece at the bottom of the 
 bore. This gun was blown up. Mr. Wiard disclaimed any knowledge 
 of this thing. I say in the report, "I have no cause to think Mr. Wiard 
 had knowledge of this transaction." 1 did so think at that time ; I do 
 not think so now. I said then, "I believe Mr. Wiard to have acted in 
 good faith in all these transactions" about those guns, but I have changed 
 my mind since, from reports that have come to me since. He says he 
 did not know it at that time, and I do not charge him with knowing it now. 
 But now there is testimony furnished in the Ordnance Office that clears 
 up this point. 
 
 92. Q." You have no knowledge since, yourself, on the subject f 
 
 A. No, sir, nothing ; only reports that have been in existence since. 
 This establishment, where Mr. Wiard had the guns made, got into a muss 
 among themselves, and have charged all sorts of things against each 
 other. I have no knowledge of the credibility of the witnesses. My 
 impression is that one of the reports was that Mr. Wiard avoided a knowl- 
 edge of where defects were in the guns ; that he kept himself aloof from 
 knowing it., 
 
 93. Q. I think you said that some of these Wiard guns fired with five- 
 pound charges burst at 10 rounds. 
 
 A. Yes, sir. 
 
 94. Q. Did those that burst show any defects either in the welds or by 
 exhibition of Iarnina3 ? 
 
 A. I think not, sir; still I would rather go back to those reports, 
 because I might do injustice from want of recollection. 
 
 95. Q. Were they of the same size and calibre of the Dahlgreu 
 50-pounder ? 
 
 A. Copies of them. 
 
 96. Q. The difference being they were of steel. 
 
 A. My impression is something like this. The finish of those guns was 
 beautiful, and made them a very attractive gun to the eye. Everything 
 appeared well about the gun. We commenced to fire with the intention 
 of going up to 1,000 rounds ; it was dropped short of that, and at that 
 time I thought remarkably well of the gun ; but when this attempt at 
 deception was discovered, the whole thing was dropped. Never was any- 
 thing done about it. 
 
 97. Q. Was it the first gun tried that you fired the 480 rounds I 
 A. Yes, sir ; the first gun. 
 
 98. Q. Were the other guns there at the same time ? 
 
 A. I could not say whether they were down at the ground or up at the 
 place where they were being finished. 
 
 99. Q. Who selected the gun to be tried ? 
 
 A. I think it was the first gun finished. I do not think there was any 
 selection about it. I have no remembrance now of any defects being 
 found about these guns that would cause one to be picked out as inferior 
 to the other. There havar been no guns presented to the government 
 that presented a better appearance than they did. 
 
 100. Q. You say of those steel guns, the rest of which were fired with 
 10 rounds, that some burst and some did not ; do you recollect how many 
 burst and how many stood the test ? 
 
 A. I could not say how many were fired. I have a sort of glimmering 
 idea that two burst. 
 
 101. Q. How do you account for the bursting of the Wiard 50-pouuder, 
 which seemed to be perfect in its structure ? 
 
EXPERIMENTS ON HEAVY ORDNANCE. 27 
 
 A. I think those guns were made out of different material. I did not 
 think so at the time, but since then 1 am inclined to think the same mate- 
 rial was not used for making all the guns. 
 
 102. Q. You think the guns which burst were npt made of the same 
 material as the ones that stood the test ? 
 
 A. I could not say that, sir, because the thing was dropped right there, 
 and no examination was carried on about it. But there is a report in 
 circulation that the last forgings were made of wrought iron. 
 
 103. Q. Was it your theory to account for the bursting of these guns 
 that there was a variety of material put into the gun in any instance, 
 which burst, or whether the gun burst was made of a material different 
 from that which stood the ordeal ? 
 
 A. Not at that time ; because I supposed everything was perfectly 
 honest and straightforward up to the moment we found the guns had 
 been tampered with, and then the thing was dropped. I never prose- 
 cuted the investigation, but since then this idea of different material has 
 been suggested. If that is so we may account for it. 
 
 104. Q. To reduce the length of the bore, then, you found they had 
 filled up the end of the bore next the breach I 
 
 A. Yes, sir; therefore the true thickness of the breach was at this 
 point less than it should be. 
 
 105. Q. Was that done in the case of the one that stood the test ! 
 
 A. O, no, sir ; only done in one gun ; no probability that it was extended 
 to any one but that. 
 
 106. Q. Then you did not prosecute the trial because this was found to be 
 the case with one of these guns? 
 
 A. Yes, sir ; that is an old established usage more than 20 years old 
 that where any defect in a gun is conceded by the contractor, it vitiates 
 the whole contract. 
 
 107. Q. A discovery of that kind might properly affect the validity of 
 the contract, or the acceptance of the gun from that contractor, but 
 would not bear on the question of the value of the gun which stood the 
 trial ? 
 
 A. Not at all. 
 
 108. Q. What is the objection to the gun that did not stand the trial ? 
 A. Nothing ; only it fell under this category of rejecting everything 
 
 that came from makers that attempted to deceive you. But whether a 
 good gun could be made on that principle is not brought in question. 
 
 109. Q. State whether the blocking or filling up the rear part of that 
 bore was a cause of weakening the gun 1 
 
 A. I should rather incline to say yes. There is generally given in the 
 construction of all guns, as in everything else,. a little excess for safety. 
 Whether this gun was heavy enough at the breech to admit of the loss 
 of two inches might be a question. I could not tell without going into 
 a minute calculation. 
 
 110. Q. What depth of metal would you think required in a gun of 
 that character in order to give sufficient strength to the breech from the 
 bottom of the bore through to the breech of the gun ? 
 
 A. I should think a less amount would answer than was in that gun. 
 I think the thickness was rather excessive in the design of that gun. 
 
 111. Q. Was that one of the guns that burst ? 
 A. Yes. 
 
 112. Q. I understand that these guns which were produced by this 
 contractor were rejected, the whole lot of them, because there was found 
 in one of them which burst, an addition of metal at the rear end of the 
 bore, put there for the purpose of reducing the length of the bore ? 
 
28 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 A. Yes, sir ; it was on account of this deception that the guns were 
 thus all rejected. 
 
 113. Q. Do you consider that as touching the question whether a gun 
 of that kind might or might not be a valuable gun ? 
 
 A. Not at all, sir. 
 
 114. Q. It is a matter which affects the question of receiving guns from 
 that particular contractor ? 
 
 A. Yes, sir. 
 
 115. Q. How do you account for the bursting of the Wiard 50-pouiider, 
 which showed perfect structure, and the endurance of a cast-iron gun, 
 made of metal only one-fourth of its tensile strength? 
 
 A. I cannot account for it, because that subject .was never exhausted. 
 The investigation was dropped, and I never recurred to it. The merit 
 of the guns, as guns, I have never taken up from that day to this. 
 
 116. Q. Then this trial, in your opinion, has not determined the merit 
 of these guns as guns, but only the claim of the contractor as a contractor f 
 
 A. That is all. 
 
 117. Q. You never considered your trial of the guns as completed, in 
 view of satisfying yourselves as to the merits of the gun itself? 
 
 A. It was not, sir ; you will find the report was closed abruptly by this 
 occurrence. A final decision never was made of those guns as guns. 
 
 118. Q. You' say you suppose they were not all made of the same 
 material I * 
 
 A. I have supposed so since that report was written ; since the disturb- 
 ance referred to took place. 
 
 119. Q. But you have no knowledge on the subject f 
 A. None at all. 
 
 120. Q. State whether Mr. Wiard was present at the trial ; and if so, 
 what explanation he gave of the bursting of the guns J ? 
 
 A. Mr. Wird has given me so many theories at times that I truly do 
 not recollect just what particular theory he then advanced. I do recol- 
 lect that we kept talking pretty much all the time we were down there. 
 
 121. Q. Do you recollect whether he did or did not explain that it was, 
 in his opinion, owing to the expansion by heating the gun? 
 
 A. Those were subjects, generally, of constant conversation with us 
 both: All kinds of theories were discussed there by us, and if Mr. Wiard 
 says he told me that at the time, I should not doubt that he did, but I 
 have no recollection of it ; I recollect his discussing these things. 
 
 WASHINGTON, November 11, 1867. 
 STEPHEN V. BENET sworn and examined. 
 By the CHAIRMAN pro tern. 
 
 1. Question. State whether you are in the United States army, and 
 your rank ? 
 
 Answer. I am a major of ordnance in the United States army, and 
 brevet lieutenant colonel. 
 
 2. Q. Did you make a proof of the powder used in the experiments 
 with Mr. Ames's gun ? 
 
 A. Two samples of powder were sent me from New York recently, by 
 Colonel Laidley, with the request that I should get the initial velocity 
 and pressure on the bore. Whether I learned at that time or was told 
 afterwards it was powder that had been used with the Ames gun I do 
 not remember; but I believe it was the powder. I made the test 4? that 
 powder in the usual way we test powder there for the service, and sent 
 
EXPERIMENTS ON HEAVY ORDNANCE. 
 
 29 
 
 him an official abstract from my record. Beyond this I don't know. 
 The following is the official record of the test that I made with those 
 samples : 
 
 
 
 Powder 
 
 Initial velocity. 
 
 Strain on gun. 
 
 Date. 
 
 g 
 
 P 
 
 
 
 1 
 
 a 
 
 5 
 
 
 M 
 
 | 
 
 1 
 
 1 
 
 r 
 
 
 <w 
 
 5 
 
 . 
 
 'S S 
 
 & 
 
 
 
 
 o 
 
 S 
 
 O 
 
 &.C 
 
 
 
 
 | 
 
 I 
 
 , 
 
 o 
 
 . 
 
 c 
 
 5 
 
 | 
 
 1 
 
 1 
 
 S3 '" 
 
 
 5 
 
 i 
 
 i 
 
 2 
 
 . 5 
 
 i 
 
 
 a 
 
 IS 
 
 i 
 
 1 
 
 1 
 
 1866. 
 Aug. 10 . 
 
 
 
 1. 7212 
 
 
 Mixed, from 
 
 Little. . 
 
 Aug. 8 
 
 18.3 
 
 1360 9 
 
 
 87 300 
 
 
 
 
 
 
 No. 5 to 
 
 
 
 
 
 
 
 
 
 
 
 
 mortar. 
 
 
 
 
 
 
 
 Sept. 13 
 
 
 
 1. 6504 
 
 
 No. 7 
 
 None 
 
 Sftnt. 11 
 
 21.8 
 
 1142 4 
 
 
 77 300 
 
 
 
 
 
 
 
 
 20.5 
 
 1214. 9 
 
 
 79, 800 
 
 
 WASHINGTON, November 11, 1867. 
 THEODORE T. S. LAIDLEY sworn and examined. 
 By the CHAIRMAN pro tern : 
 
 1. Question. State whether you belong to the army of the United 
 States, and if so to what arm of the service, and what is your rank? 
 
 Answer. I belong to the ordnance corps, with the rank of lieutenant 
 colonel of the United States army. 
 
 2. Q. What is your residence and where are you now employed? 
 A. I am stationed at Governor's island, New York harbor. 
 
 3. Q. How were you employed during the war, as an ordnance officer? 
 A. During the war I was in command of Frankfort arsenal a portion 
 
 of the time, and afterwards in command of the Springfield armory. 
 
 4. Q. For what length of time and between what dates were you at 
 Springfield armory"? 
 
 A. Eighteen months. I arrived there on the 27th of October, 1864, 
 and left there the middle of May, 1866. 
 
 5. Q. Have you been engaged in testing heavy ordnance at any time 
 during the war? 
 
 A. I have. I had, just before the war, fired a pair of Eodman guns 
 at Pittsburg, and three years ago I was engaged on the board that 
 fired Mr. Horatio Ames's 7-inch gun. 
 
 6. Q. Have you also had experience in the testing of cannon powder? 
 A. I have. While 1 was at Frankfort arsenal I was inspector of 
 
 powder. 
 
 7. Q. Will you state what the proper proportions of cannon powder 
 are, and what is the standard proof powder used for heavy ordnance? 
 
 A. Cannon powder is composed of saltpetre 75 parts, charcoal 15 
 and sulphur 10. The composition of all powder is the same, and varies 
 principally inathe size of the grains and somewhat in the density. In 
 that for heavy guns, the size of the grains is made largest. The stand- 
 ard proof of cannon powder is : 10 pounds are fired in an VIH-inch gun 
 with solid shot, and the initial velocity is taken and also the pressure 
 on the Square inch of the bore. There are two diiferent kinds of powder 
 for cannon : that is, the cannon proper and mammoth powder. The 
 cannon powder is used for the larger guns, and for the XV-inch guns they 
 use r the mammoth powder. The initial velocity for the cannon powder 
 is about 1,225, as I remember. It has been some time since I looked over 
 the figures. The pressure per square inch is about 40,000 pounds. The 
 
30 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 mammoth powder varies more than the cannon powder. It would give, 
 fired in the VHI-inch about 1,050 feet initial velocity, and a pressure of 
 not over 10,000 pounds. 
 
 9. Q. Do you regard soft powder as suitable for large guns, to give 
 them a proper velocity ? 
 
 A. No, sir; soft powder would not be suitable for large guns. 
 
 10. Q. Is there any difference in the gases, the result of combustion, 
 between coarse and tine powder made from the same constituents ? 
 
 A. No, sir; I should think not. t 
 
 11. Q. Is there any difference in the quantity of gas resulting from 
 the com burtion of coarse or fine powder? 
 
 A. I should think not. 
 
 12. Q. Which would act with the greatest force upon the square inch 
 of the interior surface of the chamber filled with either the coarse or fine 
 powder, if the chamber were strong enough to resist the expansion of 
 the gases? 
 
 A. The fine would act with the greater force on the chamber. 
 
 13. Q. Is there any residuum from powder which is not combustible? 
 A. O,yes. 
 
 14. Q. Which leaves the greatest quantity of residuum, coarse or fine 
 powder? 
 
 A. I should not think there would be any diiference. It is more the 
 circumstances under which the powder is exploded than the mere ques- 
 tion of. tli e size of the grain that determines this. 
 
 15. Q. Which will project a shot furthest from a XV-inch gun coarse 
 or fine powder, taking pound for pound? 
 
 A. The size of the grain would have to depend 011 the density of the 
 grain. If you made the grains very large, then you might make them 
 softer than if you used a smaller grain. In firing a XV-inch gun the 
 point is that you must not endeavor to impress the 'full strength of the 
 shot on the powder too rapidly. The powder must burn progressively, 
 giving the ball an opportunity to move as the force is gradually developed. 
 
 16. Q. Which of those would be furthest projected with the same 
 charge, in your opinion, solid or hollow shot? 
 
 A. The hollow projectile would start with a greater initial velocity, 
 but it would more rapidly lose its velocity than the solid shot. In high 
 elevations, with proper charges, the solid shot would probably give 
 greater range than the shell. 
 
 17. Q. Which, then, would penetrate the greatest thickness of plate 
 at a given range, in your opinion ? 
 
 A. The penetration is a question of the mass into the square of the 
 velocity. That would penetrate the furthest vrhere the mass into the 
 square of the velocity was greatest. You might arrange it so that either 
 the shell or the shot would penetrate the further. 
 
 18. Q. Then hollow shot would be projected further also if the cavity 
 were filled with lead, with the same charge ? 
 
 A. That would depend upon the charge you gave it. 
 
 10. Q. With the same, would the shell, if the cavity were filled with 
 lead, be i)rojected further than it would be if the cavity were not filled 
 with lead? 
 
 A. I think that would depend very much on what charge you used. 
 
 20. Q. Explain the distinctinction you would make in the charges in 
 order to produce the effect in one case whicji would not be in the other 
 as between a small and a large charge. 
 
 A. With a small charge the hollow shot would probably go further 
 than a very heavy projectile with the same charge, but when you come 
 
EXPERIMENTS ON HEAVY ORDNANCE. 31 
 
 to fire very large charges then the heavier projectile would go further 
 than the lighter. It is owing to the fact that the resistance of the 
 atmosphere varies in a proportion rather greater than the square of the 
 velocity. When the velocity increases very much, the square runs up 
 very rapidly, and the retardation by the atmosphere is very great. 
 With a less velbcity it is not so great. 
 
 21. Q. What force is it that ejects the shot from the gun ? 
 A. It is the expansive action of the gases in the gun. 
 
 22. Q. In your opinion is all that force of the powder expended in 
 ejecting a hollow shot from a gun ? 
 
 A. That would depend very much on the length of the bore and the 
 size of the charge. You might put in such a charge that a portion of the 
 powder would be thrown out unburned, as is often the case. 
 
 23. Q. In your opinion is the pressure of the powder per inch upon 
 'the interior surface greater with a solid shot or with a hollow shot ? 
 
 A. The heavier the projectile the greater would be the strain upon 
 the gun. , 
 
 24. Q. How heavy, then, in your opinion, would the projectile from a 
 XV-inch gun have to be in order to attain the greatest result in penetra- 
 tion of iron-plating? Have your experiments led you to a conclusion 
 about that ? 
 
 A. Make the mass into the square of the velocity the maximum and 
 you get the greatest penetrative effect. That is, of course, taking for 
 granted that your projectile has the same figure, the same point. If the 
 projectile has a different ppint, I mean front termination, that would 
 have something to do with the penetration. A round shot Avould not 
 penetrate as far as a more pointed one. 
 
 25. Q. Could you make a projectile, as heavy as the gun itself, for 
 instance, penetrate as great a thickness of plating as a hollow shot of 
 the ordinary weight ? 
 
 A. I should not think it would be practicable. 
 
 2G. Q. You said that you had been engaged in the trial of Mr. Ames's 
 guns? 
 
 A. Yes, sir. 
 
 27. Q. Where was it ? 
 
 A. At Bridgeport, Connecticut. 
 
 28. Q. How many times did you fire that Ames gun ! 
 A. Seven hundred times. 
 
 29. Q. What charges of powder and shot did you use ? 
 
 A. Charges varying from 19 pounds to 30 pounds, with shot varying 
 from 100 to 125 pounds. 
 
 30. Q. What velocities did you get ? 
 
 A. It was a difficult matter to obtain the velocity, on account of the 
 imperfect projectiles. The base or fragments from the projectile would 
 fly off, and cut the Avires ; so it was a difficult matter to tell whether the 
 wire was cut by the ball or cut^by a fragment ; and on that account we 
 did not attempt to get the initial velocity with the highest charges. 
 
 31. Q. What were the charges? 
 
 A. Most of the charges were with 19 pounds of powder. We varied 
 it, firing 150 times with 25 pounds of powder, and as many as six times 
 with 30 pounds of powder. Most of these were with the powder known 
 in the army as No. 7 powder, whi*ch is a smaller grain than cannon. 
 
 32. Q. What was the range of the gun ? 
 
 A. The ranges w^ere not determined very satisfactorily fired over the 
 water and determined by plane-tables, I think. A little over five miles 
 was the greatest range we got. 
 
32 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 33. Q. Had you a base line long enough to give you the exact measure- 
 ment of the range ? 
 
 A. Not with great accuracy ; and the persons that were using the 
 plane-tables were not accustomed to the work. 
 
 34. Q. In your opinion the charges that were used have given a 
 greater velocity and range than your figures in the report made indicated 1 ? 
 
 A. I supposed that they would. The gun was considerably worn 
 before the ranges were taken, and the windage was greater. That would 
 cause a diminution of the ranges. 
 
 35. Q. Would the charges, for instance of 30 pounds of powder, give 
 you greater range and velocity than the 19-pound charges? 
 
 A. It is fair to suppose so. Yes, sir ; I should think so. 
 
 36. Q, That was the firing in 1864, was it not? 
 A. Yes, sir. 
 
 37. Q. What was the size of that gun? 
 
 A. It had a 7-inch bore, and weighed about 19,400 pounds. 
 
 38. Q. Did you superintend the firing of the Ames gun in 1866 the 
 100-pounder? 
 
 A. I was associated with Commodore Hunt in the proof of that gun 
 also. 
 
 39. Q. Had the powder been proved that was used in that trial ? 
 A. Yes, sir. 
 
 40. Q. What pressure on the gun did that powder give, and what velo- 
 city? 
 
 A. I do not remember the velocity. I remember that the pressure of 
 one of the powders used was 87,000 pounds per square inch. That was 
 not the powder used in 1864. 
 
 41. Q. What was the difference between the powder used in 1864 and 
 that used in the 100-pounder in 1866? 
 
 A. The powder used in 1866 was a much quicker powder, and pro- 
 duced a much greater strain on the gun than that used in 1864. 
 
 42. Q. What range did that 100-pounder give in 1866? 
 
 A. The ranges of that were extremely unsatisfactory. We had three 
 stations; and the ranges as given by the two stations did not correspond 
 with each other; and I do not remember what the range was. I remem- 
 ber the fact that they were very unsatisfactory. I was in favor of trying 
 it over. 
 
 43. Q. Was the measurement unsatisfactory to you, or the range shown 
 by the. gun? 
 
 A. We had three observers, either two of which would make a com- 
 plete set of results; and then, with the three observers, we ought to 
 have three separate and distinct ranges. If the experiments were accu- 
 rately conducted those three would have agreed very closely. They did 
 not agree, but varied so much as to create doubt of their accuracy. 
 
 44. Q. Bo you think the rifling of that 100-pounder was suitable 
 rifling for a gun of that calibre? 
 
 A. I do not; I do not think the twist was quick enough. 
 
 45. Q. Do you think the range would have been greater with a greater 
 twist in the rifling? 
 
 A. I think we might have got a chance shot with this gun where the 
 range might have been as great as it would have been with a quicker 
 twist, because the friction would be less; but the twist was not sufficient 
 in all cases to keep the ball point foremost; and in that case the range 
 ordinarily would not be as great as it would be' with a quicker twist. 
 
 46. Q. Did you fire the gun at a high elevation? 
 A. We did; as high as the carriage would admit. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 33 
 
 47. Q. Are you accustomed to fire guns at so high an elevation in proof? 
 A. We do not ordinarily do it in proof? 
 
 48. Q. Why did you fire at so very high an elevation at that time ? 
 A. For the purpose of obtaining the range ? 
 
 49. Q. The elevation at which you fired that gun is a stronger proof 
 than you ordinarily subject guns of any kind to, is it not? 
 
 A. Actual experiment does not show that the strain is very much 
 increased by increasing the elevation. The ordnance department made 
 a series of experiments at Old Point Comfort with a view of testing that, 
 and found the additional strain on high elevations is very trifling. 
 
 50. Q. You think that experiment or experience does not prove that 
 it makes any very great difference. 
 
 A. Those are the actual experiments performed by the ordnance 
 department, by the pressure plug. Those are the results given by the 
 pressure plug. 
 
 51. Q. How many of those 100-pounders were you on a commission to 
 examine? 
 
 A. I think there were nine or thirteen, I am not sure which. 
 
 52. Were the guns fired in 1864 and those fired in 1866 of precisely the 
 same calibre? 
 
 A. There was only one fired in 1866. 
 
 53. Q. You were on a commission to examine how many of them? 
 
 A. I am not sure whether there were nine or thirteen. They were 
 7-inch guns ordered by Mr. Lincoln. 
 
 54. Q. I was under the impression there were three or four tested in 
 1866? 
 
 A. In 1866 we fired a single gun, at Bridgeport. 
 
 55. Q. That represented how many of these guns eight or nine? 
 A. I am not sure about that. Those were navy guns. 
 
 56. Q. State in general terms what your report was. 
 
 A. We reported that the Ames gun, when the welds were well made, 
 was a stronger gun than any that had ever been presented in the ser- 
 vice; that we did not fire them all, and were therefore not prepared to 
 say whether the other guns were good guns or not; that we could not 
 pretend to say, from firing one gun, what would be the quality of the guns 
 that had not been tested at all; and stated that it would be necessary 
 to fire them before we could determine upon their merits; after they had 
 been fired to test their strength, we thought they ought to be tested by 
 firing service charges to ascertain their durability. 
 
 57. Q. You of course did not feel authorized to go into any question 
 that might arise under the contract for making the guns? 
 
 A. We were not called upon to decide any question of that kind. 
 
 58. Q. Did you mean that your condemnation of the guns should 
 touch the question whether they should be paid for or not whether Mr. 
 Ames was entitled to be paid for them ? 
 
 A. Not at all. 
 
 59. Q. Is it possible, in your opinion, to make a weld of a wrought- 
 iron gun so perfect that it will not be a weak spot in the gun? 
 
 A. I think it can be done. 
 
 60. Q. What do you think, then, of the principle of manufacturing 
 guns as Mr. Ames has undertaken it? 
 
 A. I do not know whether Mr. Ames can make a perfect weld uni- 
 formly or not in such large masses. 
 
 61. Q. Then, when you say that you think a weld can be made so perfect 
 as not to leave a weak place in the gun, you have no experience that 
 would extend that to very large guns? 
 
 Rep. No. 266 3 
 
34 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 A. No, sir ; for instance, we weld musket barrels successfully, though 
 we do come to one occasionally that is not welded. 
 
 62. Q. Are you led to believe that a weld in the construction of a gun 
 so large as these 100-pounders can be made so perfect as not to leave a 
 weak spot in the gun? 
 
 A. It can be done ; but whether it can be done every time or not I do 
 not know. For instance, in the 3-inch guns we weld the trunnions on to 
 the body of the gun. I never knew one to give way there. 
 
 63. Q. It is usual, at least in the naval system of ordnance, and per- 
 haps with the army, to accept guns upon a trial of one of the lot. If it 
 stands the test, is not the lot received without trying each gun ? 
 
 A. In the land service we fire each gun ; but we do not fire it to 
 extremity. 
 
 64. Q. You do not submit each gun to the great trial test of a thousand 
 rounds, for instance? 
 
 A. O, no. With cast-iron guns they take one gun and fire it a thousand 
 rounds, and then afterwards make others as nearly like that as it is pos- 
 sible to make them, and accept them on a very trifling proof. 
 
 65. Q. You think, then, in the case of wrought-iron guns it is more 
 important than even in the case of cast-iron guns to submit every gun to 
 a test? 
 
 A. I think it would be necessary to give each individual gun a more 
 severe test than in the case of cast iron. 
 
 66. Q. And to give a thorough test to each gun before you would 
 condemn or accept it ? 
 
 A. I would pursue very much the same course we do with the musket 
 barrel. Every one we adopt we fire with an excessive charge, in order 
 to test the question whether it is welded or not. If it is not, it gives 
 way. If it is thoroughly welded, it does not give way. I think it would 
 lie necessary, in proving wrought-iron guns, to fire each one with an 
 excessive charge to test that question, whether it was welded perfectly 
 or not. 
 
 67. Q. What gun have you ever ,tried, if any, that you think equal to 
 this Ames gun? 
 
 A. I have never fired any gun so large as the Ames gun which I think 
 possesses as much strength as the one that we tested. I fired a small 
 gun made of wire by Dr. Woodbridge, which I think probably was as 
 strong in proportion as Mr. Ames's gun. But that was a very small gun. 
 
 68. Q. Could that system of manufacture be applied to very large 
 guns? 
 
 A. The inventor thinks it can. 
 
 69. Q. I am asking for your own opinion ? 
 
 A. I do not know ; have not sufficient information to give an opinion 
 on the question. 
 
 70. Q. The Ames guns are the largest wrought-iron guns you have 
 ever tried? 
 
 A. They are. 
 
 71. Q. Are you well acquainted with the Parrott gun ? 
 
 A. I have had very little experience with the Parrott gun. 
 
 72. Q. Have you never tested any of them? 
 A. I have never. 
 
 73. Q. Do you suppose that a Parrott gun of the same calibre would 
 stand 20-pounds charges 10 times with the same powder you used in the 
 trial of the Ames guns, giving 87,000 pounds pressure on the bore of the 
 gun? 
 
 A. I do not think it would. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 35 
 
 74. Q. What would be the comparative difference of velocity, as given 
 by the 20-pounds charge and the 10-pounds charge of powder? 
 
 A. I 00 not think you could get any rule. 
 
 75. Q. Do you think there was any difficulty as to the range, arising from 
 the kind of powder that was used in those experiments at Bridgeport ? 
 
 A. No ; I should think not. At the experiments in 1864 we used two 
 kinds of powder, both No. 7 and No. 5. 
 
 76. Q. Was there nothing in the character of the powder used giving 
 it a greater tendency to burst the gun than powder ordinarily used! 
 
 A. In 1866 the powder was a very bursting powder; but if the gun 
 should resist it as it did, there was so much of it, I should think it ought 
 to give a very high velocity and great range* 
 
 77. Q. It was in 1866 that you used a powder appertaining more to 
 the character of a fulminating powder than the other? 
 
 A. Yes, sir. 
 
 78. Q. I think you stated that you did not think this Ames gun had 
 the best rifling to adapt it to the greatest range or effectiveness? 
 
 A. I did. 
 
 79. Q. What change would you have suggested in that rifling? 
 
 A. I would have made it quicker given more rotary motion to the ball. 
 
 80. Q. Did you ever have anything to do with, or suggest, rifling of 
 that kind? 
 
 A. Nothing. 
 
 81. Q. Do you know who directed the rifling? 
 
 A. I do not know. I understood the government ordered the rifling, 
 but I do not know that to be the case from my own personal knowledge. 
 
 82. Q. Are you acquainted with the Armstrong gun? v 
 A. Only from books and newspapers. 
 
 83. Q. Do you consider thztt better than any gun we have? 
 A. I do not think it as strong a gun as Mr. Ames's gun. 
 
 84. Q. What would be your opinion of the comparative merits of a 9- 
 inch rifled gun and a 6^ calibre gun, loaded with proportionate charges, 
 fired as against an enemy, when fired at the highest velocity ? 
 
 A. It all narrows itself down to the proposition I have already stated, 
 one-half the mass into the square of the velocity is the work done. It 
 all depends on that. 
 
 85. Q. It is your opinion all these questions can be settled with 
 mathematical accuracy without reference to experience and whatever 
 we learn by the practical use of the guns ? 
 
 A. Captain Noble, of the English service, has made a series of exper- 
 iments, and finds that you can calculate with very considerable accuracy 
 the effect of any shot. We feel much more sure of all these tests, of 
 course, after we have had the actual experiment performed. But the 
 English government has made a large series of experiments, and that is 
 the conclusion Captain Noble comes to that we can calculate with very 
 great accuracy the effect of any shot projected with any given initial 
 velocity. 
 
 86. Q. Have we any rifled gun that can stand charges that will 
 give the greatest velocity to the shot of 8, 9, or 10-inch calibre? 
 
 A. We have no rifled guns in the service that I know of except the 
 Parrott guns and some experimental cast-iron guns of 8 and 12-inch 
 bore. It has not yet been tested thoroughly what endurance these guns 
 will have under high charges. 
 
 87. Q. I was asking for your opinion. Do you believe we have any 
 gun, say from 8 to 10-inch calibre, that is strong enough to resist the 
 charges that will give the greatest velocity to the shot ? 
 
 A. I do not think we have. 
 

 36 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 88. Q. I suppose it is your opinion that is very desirable ? 
 A. O, very. 
 
 89. Q. Do I understand you to say this Ames gun is the strongest 
 that you have ever tested, tried, or know anything about 1 
 
 A. When the welds are well made it is the strongest gun I have ever 
 known. 
 
 90. Q. Did you ever send more than one sample of the powder used 
 in these experiments to Captain Belief? 
 
 A. I sent him a sample of each, and the intention was there should 
 be enough to fire three rounds of each powder. The powder used is 
 known as No. 7 experimental powder, of 57,000 pounds per square inch. 
 (It is erroneously printed in the report 5,700 pounds.) 
 
 91. Q. You say you sent a specimen of each ; do you mean that used 
 in 1864 and that^used in 1806 ? 
 
 A. Yes, sir ; we usually send samples enough to fire three charges. 
 We sent samples enough to fire three rounds of that in 1864, and the 
 same of that in 1866. Wliat we used in 1864 was all the same; but 
 whether the powder used in 1866 was all the same I cannot say. 
 
 92. Q. What is the proof reported to you by Captain Bene'tf 
 A. Eighty-seven thousand pounds per square inch. 
 
 93. Q. Do you consider the kind of powder you used in 1866 suitable 
 powder to use in a gun, except it be to see whether you cannot burst it ? 
 
 A. I do not. 
 
 94. Q. It is not such powder as you would use in practice at all ? 
 A. No, sir. 
 
 95. Q. It was used, then, as an extreme fulminating powder, in order 
 to produce the greatest strain ? 
 
 A. I cannot say what it was used for. The powder was supplied, and 
 I was merely sent there to assist Commodore Hunt in the firing. 
 
 96. Q. What is the standard proof of powder used in the army for 
 velocity and pressure on the bore of the gun ? 
 
 A. Our cannon powder should not give a pressure higher than about 
 40,000 pounds per square inch. 
 
 97. Q. Do you know what the rule is in the navy? 
 
 A. I do not think in the navy they take into consideration the pressure 
 on the bore, though I cannot state certainly. 
 
 98. Q. You speak of the diificulty of making a weld, in the construc- 
 tion of a large gun like this, so perfect as not to leave a weakness in the 
 gun at that point ; I will ask you whether the fissures or cracks in a gun 
 made by welding together wrought iron are, in your opinion, always 
 the result of imperfection in the welding, or whether they are not as 
 likely to be produced by the unequal contraction of the iron in the mass 
 of the gun ? 
 
 A. We never discovered any fissures except rings, and I supposed 
 those were caused in all cases by imperfect welds. 
 
 99. Q. If there was unequal contraction in cooling of one of these rings, 
 might it not produce a fissure ? 
 
 A. I do not see how it could produce a fissure such as we found. The 
 guns were manufactured by a series of rings put together one on top of 
 the other. 
 
 100. Q. Might' there not be a difference in the density of the metal of 
 different parts of the same ring I 
 
 A. There might be. 
 
 101. Q. Would not that produce unequal contraction when the ring 
 came to cool? 
 
 A. It would. 
 
EXPEKIMENTS ON HEAVY ORDNANCE. 37 
 
 102. Q. If in consequence of contraction there was an opening of the 
 seam, making a fissure, or a giving way of the metal anywhere, would 
 it not be more likely, in your opinion, to be at the point where the two 
 rings met and the weld took place than at any other ? 
 
 A. I do not see that it would. It is understood that the gun is actu- 
 ally forged hollow, and has an opportunity to contract. 
 
 103. Q. When you speak of the pressure of powder on the square 
 inch will you state what instrument you use for determining that pressure 1 
 
 A. We use what is known as Bodman's pressure piston. It is 
 described in the Ordnance Manual. 
 
 104. Q. Do you think that a reliable or infallible instrument for such 
 measure ? 
 
 A. I do not think it is infallible. It is the best that we have. 
 
 105. Q. Does that give the pressure actually, or what you call the 
 momentum of the gases? 
 
 A. There is a difference of opinion about that. 
 
 106. Q. I want yours. 
 
 A. I think it gives it very nearly. It is undoubtedly the momentum 
 of the part of the piston that moves ; but the distance this piston travels 
 is very small. 
 
 107. Q. Capable of being observed, though, accurately? 
 A. O, yes. 
 
 108. Q. Did I understand you to say that the velocity and range were 
 not determined by the highest charges that you used ? 
 
 A. The velocity was not determined by the highest. The range was. 
 
 109. Q. Was the velocity or was the range, either or both of them, 
 greater for the larger charges that were used in these experiments'? 
 
 A. We only determined the initial velocity, I think, for the 19 pounds 
 of powder, not for the larger charges. Owing to the difficulty which I 
 speak of, the fragments of the shell flying oif and breaking the wires, 
 we did not regard it as reliable, and therefore gave it up. 
 
 110. Q. Do you know anything about the experiments with the Par- 
 rott guns at Charleston, and the practical use of them there! 
 
 A. I do not, except what I have read or heard nothing from actual 
 knowledge. 
 
 111. Q. Do you know whether the velocity obtained with these experi- 
 ments with this gun was greater than that obtained at Charleston from 
 the Parrott gun with smaller charges, with the same elevation? 
 
 A. You can but know, or think, at any rate, it was greater, because 
 the charges at Charleston must have been less. 
 
 112. Q. Were the samples of powder sent by you to Captain Benet 
 the same that were used? 
 
 A. They were. 
 
 WASHINGTON, D. C., November 12, 1867. 
 
 NORMAN WIARD re-called. 
 By Mr. CAMERON : 
 
 Question. Do you know what varieties of calibres and ammunition 
 were introduced in the service,during the war, and have you any opinion 
 as to the importance of establishing a uniformity of calibres and ammu- 
 nition ? 
 
 Answer. I am familiar with the calibres of our guns ; and when I relate 
 some of the facts within my knowledge I think you will agree with me 
 that our ordnance departments have got our small-arms, artillery and 
 
38 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 guns into most reprehensible confusion, for want of uniformity in calibre 
 and ammunition. The ordnance departments of France and England 
 have no greater differences embodied in the systems they have adopted 
 than there is between the two branches of our service. The calibres, 
 models, chambers, and ammunition of the navy are utterly unlike those 
 adopted for the army. The navy rifled 12-pounder boat howitzer has a 
 calibre of 3 ^ inches, while the army 12-pounder rifled guns are of the 
 calibres of 3 inches, 3 T 2 ^ inches, 3^, inches, and 3 y^ inches. The navy 
 12-pounder has a parabolic form, of chamber, while the army gun has 
 either no chamber or it is cycloidal. The navy 12-pounder smooth-bore, 
 although of the same calibre as the army gun, has a different form of 
 chamber. Apparently each of these chambers has been devised to prevent 
 the use of navy ammunition in the army gun or army ammunition in the 
 navy gun. The models of the two guns are entirely different, and neither 
 will go on the other's carriage, the army gun being furnished with trun- 
 nions and the navy gun having the loop and loop bolt of the old carro- 
 nade. The sights are of an entirely different kind in the two guns, and 
 so graduated as to make it impossible for a navy gunner to use an army 
 gun, or an artillerist of the army to use a navy gun for an emergency 
 one being graduated to seconds of time and the other to degrees of eleva- 
 tion. The 20-pouuders and 30-pounders of the navy are different from 
 the army guns of the same kind, the navy guns having a shark's mouth 
 for the breeching, which is not on the army guns. The navy Dahlgren 
 20-pounder, 30-pounder and 50-pouiider are of a different model, calibre, 
 form of chamber, and kind of rifling from any other gun in the navy or 
 army, all purposely different, seemingly, to insure the use of a certain 
 kind of projectile which Captain Dahlgren claimed to have invented, 
 being essentially the same as the so-called Dyer projectile, but which 
 was found latterly to have been used and patented by others long before. 
 The Dahlgren, like the Dyer, was abandoned after large numbers of 
 them had been produced. The Dahlgren 50-pounder has a calibre of 5 JL 
 inches, as' if the inventor, from paucity of ideas, could only produce a 
 new diameter of calibre which no other person had thought of. 
 
 The army 3 inch gun, it has been said, was rifled in a peculiar way to 
 adapt it to the Dyer projectile, which being condemned, it was happily 
 found could be used with the Hotchkiss projectile. The navy have, then, 
 a 60-pound er Parrott, adopted, as shown by the lucid explanation of Cap- 
 tain Wise, Chief of Ordnance, so as to have something between the 30- 
 pounder and the 100-poimder; and no other reason is. given for its adop- 
 tion ! The navy has VHI-inch, IX-inch, Xl-inch and XHI-inch smooth- 
 bores, as if the navy chose odd numbers of inches for luck. The army 
 sm oo th-bores are 6-inch, (32-pounders,) 8-inch (64-pounders,) and 10-inch, 
 (130-pounders.) The navy chose the old Konian numerals to describe the 
 calibres of their guns, probably because the army had some fanciful pre- 
 emption right to the more common figures. In the guns adopted and 
 actually issued to service in the two branches of the service, there is not 
 a single example of uniformity, in either rifle or smooth-bore, in the 
 20 calibres adopted of those below the calibre of the 30-pounder. I append 
 a tabulated statement of calibres, models, weights, chambers and charges. 
 
 How long it has taken two complete organizations of ordnance officers, 
 educated at the public expense, experimenting, with the treasury of the 
 United States to pay the bills ; what the cost of the effort has been in 
 money ; how much treasure has been wasted in furnishing the arms to the 
 extent to which they have been supplied after they were adopted ; how 
 much life of citizen soldiers and honor of the nation have been misdi- 
 rected and wasted, it is not within my power to even estimate. I am, 
 
EXPERIMENTS ON HEAVY ORDNANCE. / 39 
 
 however, confident that no example of such imbecility of invention and 
 paucity of practical results ever before attended an effort conducted with 
 so much flourish, on so grand and expensive a scale, with objects so 
 important, and where the class of persons charged with so important a 
 branch of the public service for so many critical years have brought their 
 departments into such confusion. They are entitled to the execrations 
 of every citizen, and would receive them, too, were the facts known. 
 
 The calibres of small-arms and the ammunition for them although it 
 would seem impossible, so minute must be the differences where the 
 greatest is .70 of an inch are as diverse as in the field, siege and heavy 
 guns, and similar want of uniformity exists. In order to find divisions 
 for sufficient diversity the dimensions of calibres are given inhundredths 
 or thousandths of an inch, and our muskets and carbines alone range* 
 from .40 to .69 We have an Enfield rifle of .57 and a Springfield of .58, 
 but no instruments common in the hands of inspectors or soldiers for 
 determining the difference. Hence, during the war the army has fre- 
 quently found itself on the field of battle facing the enemy with ammu- 
 nition one-hundredth of an inch too large to be inserted in the gun. 
 About 20 different calibres of ammunition were furnished the Burnside 
 expedition, from .44 to .69; and, lest one transport carrying all of one 
 calibre should be lost, each vessel had to be supplied with an assorted 
 cargo made up of certain proportions of the whole. It was the same with 
 the Banks expedition, making it necessary to stow away the cargo with 
 considerable skill, so that any of the various kinds could be got at upon 
 the recurrence of an emergency, a ]1reliminary caution likely to be over- 
 looked in the hurry of the embarcation of an army; the consequences of 
 neglecting which and no cautionary order by the ordnance department 
 is given on such an occasion are easy to conceive. A great many hun- 
 dred thousands of Springfield muskets are now to be sacrificed to uni- 
 formity of calibre. The ordnance department in this, as in the question 
 whether it was better to have breech or muzzle loaders, were undecided 
 during the war, only concluding* 1 their cogitations when the emergency 
 had passed. In 1861, when every tyro knew that a breech-loader was 
 best in fact nobody but an idiot or an officer of our ordnance depart- 
 ment would ever decide otherwise the Chief of Ordnance of the United 
 States held and advocated that "a Harper's Ferry smooth-bore muzzle- 
 loading gun, with buck and ball, was the best arm that could be placed 
 in the hands of a soldier;-' and asserted he would have no such gun as a 
 breech-loader in service because it would require a mule to carry the 
 ammunition for each soldier it would be shot away so fast ! Now it is 
 proposed to alter all the Springfield rifles on hand to breechloaders; 
 and in order to get uniformity of calibre, i. e., to have the musket con- 
 form to the calibre of the carbine, the barrel is to be reamed out, another 
 barrel inserted, the new lining is to be bored out, straightened and rifled ; 
 the breech of the barrel is to be bedevilled by the insertion of a compli- 
 cation of parts, and thus a new gun is to be made. But, gentlemen, this 
 will cost more than to make a new gun; and that is not all, for although 
 it is an approach to uniformity of calibre, it brings us no nearer to uni- 
 formity of ammunition than we were before, because the carbine charge 
 is not sufficient for the musket, and when this improvement is adopted 
 we shall have another slight diversity, as in the case of the Enfield of 
 .57 and the Springfield of .58, for the chamber of the carbine is not long 
 enough for the musket cartridge, and the carbine charge is not heavy 
 enough for the breech-loading musket. 
 
40 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 WASHINGTON, November 12, 1867. 
 Q. A. GILLMORE sworn and examined. 
 
 By the CHAIRMAN pro tern. : 
 
 1. Question. Will you state if you are in the military service of the 
 United States ; if so, in what arm of the service and with what rank ? 
 
 Answer. 1 am in the service of the United States, major in corps of 
 engineers and brevet major general in the United States army. 
 
 2. Q. Were you in command at the siege of Charleston ? 
 
 A. Yes, sir j in command of the besieging forces. After the April 
 attack by the navy I had command of the land forces. 
 
 Will you state how many men composed your army and what was the 
 plan of attack there ? 
 
 When I assumed command in June, 1863, I found the troops occupy- 
 ing the coast from St. Augustine, Florida, to the north end of Folly 
 island. I got together 10,000 men in round numbers, for offensive ope- 
 rations, leaving the most important points of the coast garrisoned in 
 sufficient force for security. The plan of operations was to make a 
 descent upon Morris island, carry its defences by assault or siege, and 
 then demolish Fort Sumter so that the navy could enter the near harbor 
 and move up to the city. A siege of Charleston by land was never con- 
 templated in my instructions or in any of my plans. This plan the 
 General-in-chief informed me grew out of a request by the naval authori- 
 ties for assistance in making another attack upon Charleston. They 
 desired Fort Smnter, which had repulsed them in April, to be eliminated 
 from the fight. 
 
 By Mr. CAMERON : 
 
 3. Q. What sort of gnns had you there in use ? 
 
 A. All the heavy guns were Parrotts ; I had field batteries besides. 
 
 4. Q. What were the charges used in the different calibres of these 
 guns ? 
 
 A. I do not recollect j I used the charges prescribed by Mr. Parrott, 
 if that would be an answer, in all cases. 
 
 5. Q. What powder did you use in the 100, 200, and 300-pounders ? 
 A. We called it " cannon" powder. It was not mammoth powder. I 
 
 think we had a little mammoth powder for a few trials, but we used 
 cannon powder. 
 
 6. Q. Was that furnished you I 
 
 A. Yes, sir ; furnished us by requisition on the Chief of Ordnance. 
 
 7. Q. What is the velocity and pressure on the bore of the gun with 
 this powder ? 
 
 A. I cannot tell you that. 
 
 8. Q. Can you tell me what 'does No. 7 powder give I 
 A. No, sir. 
 
 9. Q. Nor No. 5 ? 
 
 A. No, sir ; that requires a technical knowledge which I do not pos- 
 sess just now. I have known at various times, but I forget it. The 
 smaller the powder the greater the pressure generally ; but I do not 
 recollect the pressure in pounds. 
 
 10. Q. What range did you get from 100, 200, and 300-pounders I 
 
 A. The 200-pounder fired from Morris island to the city of Charleston. 
 I should have to refer to my report to see the number of yards. I only 
 know it was over 7,000 yards, because we had means of knowing that 
 the projectiles went into the city, and it was 7,000 yards to the nearest 
 point. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 41 
 
 11. Q. Did they go into the city to be effective ? 
 
 A. The shells from the first gun we fired went through houses ; did 
 not accomplish any immediate military effect. 
 
 12. Q. What is the cost of placing a " Swamp Angel" for use? 
 
 A. It is difficult to give the cost of the battery. There were $4,000 
 worth of sand-bags used in it. That was the only material I had to 
 buy. The timber we cut in the woods on the adjoining island and 
 carried up there. 
 
 13. Q. What time did it occupy ? 
 
 A. It occupied about three weeks, I think. 
 
 14. Q. And how many men were employed at it 1 
 
 A. I suppose there were two or three parties of fifteen or twenty men 
 apiece ; some carrying sand-bags, some floating logs down to the place, 
 some cutting logs on the adjacent island and hauling to where they 
 could be floated. They were generally towed across the narrow river 
 by a steam-tug. 
 
 15. Q. How far was it placed from the city ? 
 
 A. Seven thousand yards from the nearest point. 
 
 16. Q. W T hat damage did it do to the city while under your direction ? 
 
 A. That gun burst after the thirty-sixth round. I judge that three- 
 fourths of all the projectiles fired from that piece entered the city. I 
 did not put another gun there. 
 
 17. Q. To what do you ascribe that failure? 
 
 A. The gun was fired at a very high elevation, which gives increased 
 strain upon a gun. Exactly how much additional strain the gun has to 
 sustain at an elevation above the horizontal I do not know, but it is 
 regarded as considerable. 
 
 18. -Q. If it had been perfectly level, how long would it have lasted? 
 A. It ought to have lasted 300 or 400 rounds; and I judge because 
 
 the average endurance of his guns is 310 rounds. I have always regarded 
 the form of Mr. Parrott's large guns as defective. 
 
 19. Q. What damage do you think was done by the guns that did that 
 firing? 
 
 A. The lower two-thirds of the city, in the first place, was rendered 
 untenable by the batteries playing upon it. I should judge three-fourths 
 of the houses in that portion of the city were to a certain extent injured; 
 sqine of them almost destroyed. 
 
 20. Q. Do you think if you had used greater charges of powder in 
 those guns they would 'have been more effective, if they had been able 
 to withstand the pressure? 
 
 A. They would not have been more effective, so long as we reached 
 the city with the charge we used. The projectiles would have gone a 
 little further, but there would not have been a very great increase in 
 falling. 
 
 21. Q. Would they have stood a greater pressure of powder than you 
 did use ? 
 
 A. They would have stood a greater pressure of pow r der a few rounds, 
 but would not have stood so many rounds. I adopted the plan of using 
 Mr. Parrott's own charge. He prescribed a charge for his gun, and I 
 thought it was but fair to use that charge. 
 
 22. Q. Do you know anything of the Ames wrought-iron gun? 
 
 A. Yes, sir ; something of it. I witnessed the process by which it 
 was made ; and I was president of a board of officers that tested one of 
 Ames's 7-inch rifles in the autumn of 1864. 
 
 23. Q. Could you have done any better on the city with one of those 
 guns than you did with Parrott's ? 
 
42 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 A. If I had had guns all as. good as the one we tried, I could have done 
 better. 
 
 24. Q. What sort of a gun was it ? 
 
 A. This was a wrought : iroii gun, calibre of 7 inches, rifled for a pro- 
 jectile weighing about or over 100 pounds; I forget what it was. 
 
 25. Q. Do you know how the velocity of the shot from it compared 
 with that from the Parrott? 
 
 A. I presume, with the same charges, the initial velocity would be the 
 same. 
 
 26. Q. Had it endurance to stand a higher charge of ammunition ? 
 A. I think it had. We used higher charges in testing this gun than 
 
 Parrott had prescribed for his. 
 
 27. Q. How many rounds did that undergo ? 
 
 A. I believe w^e fired it 713 times, and many of those charges were 
 considerably higher than Parrott uses. 
 
 28. Q. Was it fired at greater elevation, too I 
 
 A. It was fired at greater elevation than the swamp-angel battery. 
 
 29. Q. Were the elevations in the trials equal? 
 
 A. No, sir; but some of the elevations were quite high. Some between 
 20 and 30 degrees, 1 believe. We fired Parrott's gun as a mortar; I 
 think it was nearly 40 degrees. We fired Mr. Ames's gun several times 
 at high elevation, but it was not as high as that. 
 
 30. Q. You got Ames's up to about twice the amount of charges ? 
 
 A. I think we did; yes, sir. Tke effect upon the gun was to enlarge 
 the bore at the seat of the charge, I think about three-eighths or one- 
 fourth of an inch. That enlargement showed on the outside of the gun 
 in a little bulge all around it. The board reported favorably of that 
 gun, recommended it should be bored out to an 8-inch calibre and tried 
 again. That was subsequently done, I understood, under another board. 
 I had nothing to do with it. 
 
 31. Q. Did you see any of those Ames guns afterwards? 
 A. No, sir ; I never had any of them. 
 
 32. Q. Did you ever ask for any of them ? 
 
 A. I had no command after that where I had occasion to use heavy 
 guns. I took command subsequently in the south, but no operations 
 that required heavy guns were going on. 
 
 33. Q. Then you could not tell me in how much less time you could 
 have accomplished the chief object on the city with the Ames guns if 
 you had had them in place of Parrott's. 
 
 A. I did not lay much stress on accomplishing any special object on 
 the city. I could have demolished Fort Sumter sooner if I had had 
 good guns. 
 
 34. Q. Suppose you had had the Ames gun there, or something like 
 it a gun you could have relied upon for as much force as you pleased ! 
 
 A. If I had had a gun that would have stood all the rounds required, 
 I should have saved one-third of the time in demolishing Fort Suniter, 
 for it required a great deal of time in getting up these heavy guns when 
 one of them burst prematurely. 
 
 35. Q. I have always had the impression you were very much embar- 
 rassed before Charleston for the want of proper ordnance. How was 
 that, general ? 
 
 A. We supposed we had the best, though I always supposed a gun 
 ought to stand 1,000 or 1,200 rounds, and Parrott's heavy guns stood on 
 an average 310. 
 
 36. Q. We had none but Parrott's when you went there ? 
 
 A. Never had any heavy guns but Parrott's. We tried to study into 
 
EXPERIMENTS ON HEAVY ORDNANCE. 43 
 
 the cause of this bursting of guns prematurely. Some officers attributed 
 it to one cause and some to another. Parrott attributed it entirely to 
 the shells bursting inside. I thought it was c^ue mostly to the defective 
 form of the gun in the large guns. I do not want a better small gun 
 than Parrott's. His 30-pounders and 20-pounders have, as a general 
 rule, very great endurance. I suppose after getting a good small gun he 
 was allowed to suppose he could furnish every sort of a gun, and he had 
 such control of the ordnance department that they would take none but 
 his. He applied the same rules in getting out large calibres as with 
 small ones. 
 
 37. Q. Suppose you had everything there of the right sort of material 
 when you first made your demonstration on Charleston, what amount 
 of saving of money would there have been ? can you give anything near 
 it? 
 
 A. If I had had good guns I could have done my share of the work 
 three weeks sooner, I think. After that it was for the navy to go in 
 according to agreement. 
 
 38. Q. What would probably have been the saving in life and wounded 
 if you had had guns that would not have burst ? 
 
 A. We lost no men by the bursting of guns. Do not think we lost a 
 single life by it. 
 
 39. Q. Dy you remember how many guns were burst ? 
 A. Including one small gun a 30-pounder I burst 23. 
 
 40. Q. In what length of time I 
 
 A. During the summer and autumn of 1863, and in the winter of 
 1863->64. 
 
 41. Q. How many did you throw out of use besides those actually 
 destroyed ? 
 
 A. We mounted and used all the guns sent to us as long as they were 
 serviceable. They either became unserviceable by bursting open or by 
 the muzzle blowing off, and we charged them all as bursted guns, making 
 the 23. The 30-pounder which is included in that number was tired at 
 the city of Charleston 4,600 rounds at high elevation. 
 
 42. Q. So you think that small guns do better than large ones ? 
 
 A. Yes, sir ; and other officers who have used them entertain the same 
 opinion. 
 
 43. Q. Who took command after you, general ? 
 
 A. I moved with the tenth army corps to James river and left the 
 command temporarily with General Hatch, and General Foster arrived 
 almost immediately afterwards, and took command. 
 
 44. Q. How many Parrott guns burst after that in command of Hatch 
 and Foster ? 
 
 A. When I went back to the command of the department again in 
 1865, I found the records of the artillery service in the department and 
 got them together, and I found General Foster had kept up the bom- 
 bardment against Charleston and Sumter, and had burst 27 guns, accord- 
 ing to the report of his chief of artillery. 
 
 45. Q. Were any disabled besides those burst ? 
 
 A. I found no report of any disabled except burst. 
 
 46. Q. Were your operations on Charleston any way interfered with 
 by the want of cannon such as you had confidence in f 
 
 A. Only by the delay which was occasioned by the bursting of the 
 guns in the demolition of Fort Sumter ? 
 
 47. Q. That was a great deal, was it not ? 
 
 A. It would have been a great deal if the programme had been car- 
 ried out, perhaps 5 but the programme was not carried out at all after- 
 wards. 
 
44 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 49. Q. I remember the country had an intense interest fixed upon you 
 for a time, and for a while everything was going on finely ; but for some 
 reason it was supposed you were not able to proceed, and I never could 
 understand the cause of it. There was a general impression in the 
 country that you were not supplied properly. 
 
 A. I was supplied with everything necessary, and I did what I was 
 sent there to do. 
 
 50. Q. It was not your instructions to do anything towards the demo- 
 lition of Charleston ? 
 
 A. I was to demolish Fort Sumter, so it would not be in the way of 
 the navy. The firing on the city was done on my own responsibility. 
 
 51. Q. If they had let you alone would not you have taken that city 1 ? 
 A. If they had given me a navy I would have taken it. I had not 
 
 troops enough to land on the mainland. 
 
 52. Q. How many more troops ought you to have had 1 
 
 A. In 1863 I ought to have had 10,000 more men to have made my 
 force equal to Beauregard's. 
 
 53. Q. That could have been easily supplied? 
 
 A. The operations in the valley of the Mississippi were pending; then, 
 and all the spare men were going there, to Port Hudson and Vicksburg 
 an(I other points. 
 
 54. Q. Could you with the Ames gun, like the one you fired at Bridge- 
 port, have reduced all the enemy's works and the city of Charleston in the 
 time you were there? 
 
 A. I do not think I can answer that. We did not want any more 
 guns. We wanted a navy. We had guns enough. 
 
 55. Q. Give your opinion of the general merits or defects of a heavy 
 wrought-iron gun, as compared with those made of cast iron. 
 
 A. Well, I have thought from, the experiments at Bridgeport that we 
 had no heavy cast-iron gun as good as Mr. Ames's wrougnt-iron gun. 
 Recent trials with our 15-inch gun have been very satisfactory, and it is 
 possible that gun will be able to do all the ordnance department claim 
 for it. I do not know. 
 
 56. Q. If it does that will it be any better than the Ames gun ? 
 A. No, sir, it will not be any better. 
 
 57. Q. Do you think it possible to produce uniformity of weld in 
 wrought-iron guns of large calibre? 
 
 A. I think it is, by Mr. Ames's process, and I think if a defective 
 weld does get into a gun it will be developed in proving it. 
 
 58. Q. Give me your opinion generally about the use of wrought-iron 
 guns and their value as compared wilh cast ones. 
 
 A. A wrought-iron gun, in my opinion, if made by this process of 
 welding rings together, which is Mr. Ames's patent, and we can get a 
 gun without defective welds, would be one of the most valuable guns 
 we could have; and I believe that a defective weld would be developed 
 in proving a gun. If it does not break in the proof charges say eight 
 or ten heavy charges I should regard the welds good. 
 
 59. Q. That would be easily tried, then, would it not? 
 
 A. Yes, sir ; although a defective weld was discovered in the gun we 
 tried at Bridgeport on the second trial. 
 
 60. Q. And how long did it last? 
 
 A. It fired 713 rounds with us, but I believe only fired a few rounds 
 after they bored it out to enlarge the calibre. It was heavy enough for 
 an 8-inch gun, as compared with the weights of guns of that calibre. 
 
 61. Q. It burst after having been bored out, did it? 
 
 A. So I understood. I was not connected with the experiments made 
 
EXPERIMENTS ON HEAVY ORDNANCE. 45 
 
 afterwards. No piece of cast metal, in my opinion, unless possibly it is 
 cooled on the inside, will make a good gun all in one piece. I do not 
 know but the cooling inside will secure a good gun of very large calibre 
 out of one piece of iron, but I am not satisfied of it entirely; but I do 
 not believe any piece of cast metal, unless it is cooled on the inside, can 
 possibly make a good gun of large calibre. 
 
 62. Q. Suppose you had taken Charleston when you first went down 
 there, what would have been tke effect of it on the country! Would 
 not Savannah, Wilmington, and all the other southern ports and places 
 have give up at once? Did not they look on Charleston as the great 
 citadel of the south, on which everything depended? 
 
 A. They looked upon Charleston as a very important place for block- 
 ade-running. Its military strength never was very great, independent 
 of its being used as a source of supply through blockade-running vessels. 
 Wilmington was equally good. Savannah was used a little through the 
 by-channels. They did not go up the Savannah river, but went up the 
 Wilmington river. I think the effect upon the war would have been to 
 shorten it, though I cannot say how much. I should have regarded 
 Vicksburg as about the the most important capture of any city during 
 the war. But the failure to take Charleston is not intimately connected 
 with the subject of heavy guns. It opens another field entirely. 
 
 63. Q. Do you know any gun superior to the Ames gun for strength 
 and endurance? * 
 
 A. I do not ; but there may be such a gun. My knowledge of heavy 
 guns just now may not be up to the times. I have been on other duty 
 for a year, exclusively. 
 
 64. Q. But daring the war you knew all about them? 
 
 A. Yes, sir ; had a good deal to do with heavy guns up to the time we 
 tried the' Ames gun. Do not think we had anything as good as that, 
 and the board expressed that opinion in their report. 
 
 65. Q. You have not heard of any since? 
 A. No, sir. 
 
 66. Q. Did the wrought-iron gun enlarge more than the cast-iron or 
 other ones? 
 
 A. They are apt to. 
 
 67. Q. So as to make them materially larger? 
 
 A. They enlarge considerably more than cast-iron, but they will stand 
 a larger charge without bursting. 
 
 68. Q. Then the enlargement is not material, is it? 
 A. Yes, sir; it becomes so after a while. 
 
 69. Q. Is there any injury by an enlargement of yL, -i, or 1 of an inch 
 to the calibre? 
 
 A. There is no injury in the accuracy of the firing, because that enlarge- 
 ment takes place at the seat of the charge, and not along the bore. 
 
 70. Q. With the charge used by Mr. Ames in his gun is'it likely to en- 
 large much ; or did those that you saw enlarge much with the use of his 
 ammunition ? 
 
 A. We did not use Mr. Ames's ammunition. 
 
 71. Q. Well, with the ammunition you used, was there much enlarge- 
 ment ? 
 
 A. The enlargement was not very great until we commenced to use 
 large charges. 
 
 72. Q. Is it your opinion that cast-iron rifled cannon can be made to 
 stand sufficient charges of powder to be effective against iron-clad ves- 
 sels or against fortifications that are now being constructed? 
 
 A. I have not formed any opinion on that subject, and very few officers 
 have, I think. 
 
46 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 73. Q. How many times, in your opinion, would the cast-iron 100- 
 pounder rifled gun stand the charge of quick-burning powder, 20 pounds 
 to the charge, and 100-pound shot I 
 
 A. That is a pretty big charge. How many rounds it would stand is 
 mere guess. I do not know of any cast-iron gun that would stand 500 
 such charges, and I should be afraid to trust them to stand 200. 
 
 74. Q. What is your opinion about the necessity of using rifled cannon I 
 A. If the heavy Rodman guns prove a success, we want very few 
 
 rifled cannon. If they wiH not stand the heavy charges which the 
 ordnance department expect them to stand, we shall have to resort to 
 rifled cannon to get the necessary velocity and weight of ball to pene- 
 trate iron-clad vessels. 
 
 75. Q. That is an experiment yet ? 
 
 A. Yes, sir. If the 15-inch gun will stand 100 pounds of powder right 
 along through 800 or 900 rounds, we can beat off any iron-clad fleet with 
 those guns, I think. 
 
 76. Q. That you do not know yet I 
 
 A. Only know that they have stood several rounds. 
 
 77. Q. Would you think a gun weighing 20,000 pounds capable of pene- 
 trating the same thickness of earth, air, or iron, with 45 pounds of pow- 
 der as a 15-inch gun weighing 49,000 pounds, with 100 pounds of powder, 
 a more desirable gun to obtain for the service ? 
 
 A. In some respects it would be the most desirable gun 5 in others it 
 would not. 
 
 78. Q. It would be a great deal cheaper ? 
 
 A. It would be cheaper, and a more desirable gun when you wanted 
 to punch a hole through ; but when you wanted the racking effect of a 
 large mass thrown against the side of a vessel, I do not think this small 
 gun would be as good as the big one. 
 
 79. Q. Is not that a question with the English authorities, which is 
 the best effect to produce ? 
 
 A. No $ but it is yet a question with us. 
 
 80. Q. Explain your views as to the difference in value of light and 
 heavy guns capable of performing the same amount of work. 
 
 A. The light guns are the most desirable, if they will do the kind of 
 work you want done, of course. 
 
 81. Q. Did you use any smooth-bore guns at all there at Charleston ? 
 A. No, sir $ not large guns. 
 
 82. Q. Why? 
 
 A. All our ranges were very long. I used smooth-bore guns at Fort 
 Pulaski. There we had only a mile to breach, and I did not have any 
 new rifled guns. I had our old 42-pounder and 32-pounder guns rifled 
 out to fit James's projectile ; and then I had the 8-inch and 10-inch 
 smooth-bore columbiad ; but used none of them in our heavy batteries 
 before Charleston, at all. 
 
 83. Q. Did not use them as a matter of choice, not because you did 
 not have them ? 
 
 A. They would not have been effective at the distance I had to fire. 
 
 84. Q. What are the charges of powder and shot used in rifled guns 
 above T ^-inch, 7, 8, 9, and 10-inch bore, and do these charges give full 
 velocity to the shot ? 
 
 A. These charges are given in a table in my report that is, the 
 charges for Parrott rifles. 
 
 85. Q. Are you willing that what is said in that report shall go as 
 part of your testimony ? 
 
 A. Yes, sir ; I am willing to take any or all this book as testimony, 
 
EXPERIMENTS ON HEAVY ORDNANCE. 47 
 
 ("Engineer and Artillery Operations against the Defences of Charleston 
 Harbor, 1863.") Here are the charges : a 200-pounder is 16 pounds of 
 powder $ a 300-pounder, which is a 10-inch bore, is 25 pounds ; and that 
 is as high as it goes. Parrott has only the 8-inch and 10-inch above the 
 G-^L-inch guns. 
 
 86. Q. How much more powder in each calibre would it take to give 
 the shot its greatest velocity ? 
 
 A. I should think the initial velocity would increase up to one-half 
 more of the charge, though there would be a good deal of unburned 
 powder. 
 
 87. Q. Then why is not that largest amount of charge put in so as to 
 give the greatest velocity ? 
 
 A. The gun would not endure it so long. 
 
 88. Q. Then the gun which would endure the more is so much better 
 than one that will not ? 
 
 A. Yes, sir, certainly ; the heavier charge the gun will endure, the 
 better the gun is. 
 
 89. Q. Do you think it a good gun that would not stand such a charge 
 the heaviest amount of charge which its calibre would allow 9 
 
 A. It is a mere question of the endurance of iron as against the expan- 
 sive effect of powder. We may not be able to get any gun that will 
 stand the charge you ought to fire to get the greatest velocity, but the 
 gun that will nearest support that is the best. 
 
 90. Q. What gun comes the nearest that ? 
 
 A. I do not know of any gun stronger than Ames's. 
 
 91. Q. Then could you tell me what would be the comparative differ- 
 ence between a gun which would stand the largest amount of powder 
 and ball, and one which would take a less amount ? Take, for instance, 
 the Ames and Parrott gun, i i all their usefulness in the service ? 
 
 A. Well, I should regard the gun that would stand 1,000 rounds as 
 twice as valuable as one that would stand 500 rounds. 
 
 92. Q. Would not it be more, because there is all the expense of getting 
 it ready, and loss of time in getting another one ? 
 
 A. Well, twice as valuable, at least ; unless I made a calculation I 
 could not tell exactly the difference. 
 
 93. Q. Are you familiar with the mode of construction of the Ames 
 gun? 
 
 A. Measurably so ; I saw a portion of the process of making one, and 
 understand how it is made by description 5 it is described in that report 
 of mine. 
 
 94. Q. What is the particular value of its construction over a cast-iron 
 or any other one? 
 
 A. I understand one of the strong points in favor of that mode of con- 
 struction is that the strain upon the metal is brought lengthwise of the 
 fibres to a certain extent. 
 
 95. Q. How are the fibres formed ; in parallels, or in transverse sections ? 
 A. The outer ring, if I recollect, is a hoop all around the gun. The 
 
 inner portion of each ring is a block of iron with a hole punched in it 
 if I do not forget. 
 
 96. Q. What advantage is there in that mode of formation ; is that 
 what gives it its power to resist f 
 
 A. The laminad of the wrought metal lie transversely to the axis of the 
 gun, in the inner portion of each ring. 
 
 97. Is not the fibre in iron the result of extension, as candy is drawn 
 out by the confectioner from crystallized sugar ? 
 
 A. Yes, sir. 
 
48 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 98. Q. Does Mr. Ames's system involve initial tension ? 
 A. I should not think it did. 
 
 99. Q. Does it give the fibre of the metal a transverse direction around 
 the gun ? 
 
 A. A portion of the fibre runs round the gun $ a portion of it lies in 
 laminae, transverse to the axis of the gun. 
 
 100. Q. Would not the fibre be destroyed by it after heating and a new 
 crystallization be formed ? 
 
 A. Under continued heating there is a new crystallization to a certain 
 extent, but where it commences and how rapidly it progresses I do not 
 know. 
 
 101. Q. If you had sections in the state of tension, deemed necessary 
 to best restrain the pressure from within the gun, would the tension 
 remain after the gun had been heated to the welding temperature 1 
 
 A. No 5 it would take off the initial tension. 
 
 102. Q. Do you know why the Armstrong gun was fired with enlarg- 
 ing charges previous to the last boring to the final calibre! 
 
 A. I do not know, though I think I could guess. It was to give the 
 tension. 
 
 103. Q. If you were before an enemy, and his guns would stand a 
 third more powder than yours, what would be the value of each ? 
 
 A. He could reach me before I could him ; that is about it. 
 
 104. Q. Could he not destroy you before you could get ready ? 
 
 A. There would have to be some manoeuvring then, I guess, to get out 
 of his way. However, that problem cannot be figured right down in that 
 way. He would have an advantage on the water, undoubtedly, and the 
 advantage might be measured ; but on the land he would not have that 
 advantage. Probably nearly all the actions on land take place within 
 the range of the weakest ordnance they have. But an enemy on the 
 ocean, having the longest range, can lie at Ms own distance and fight 
 entirely beyond the range of his adversary's guns. 
 
 105. Q. Did you notice such uniformity in the manner of bursting 
 guns where accidents have happened under your direct observation as 
 to lead you to think there was a law governing the forces acting to rup- 
 ture them ? 
 
 A. The force of exploding powder is applied according to a certain 
 law always, of course ? 
 
 106. Q. Do you think the pressure of the gas of the powder is uni- 
 form at all times of course, with all the circumstances the same ; is it 
 something that can be calculated definitely with uniformity $ 
 
 A. The force of the same powder fired under precisely the same cir- 
 cumstances ought to be, and I should think would be, the same. 
 
 107. Q. Do you think that, under the most favorable circumstances of 
 lubrication of the shot, smoothness of the bore, and time of ignition of 
 the charge, that the force and velocity imparted to the shot is a fair 
 evolution of the amount of work the powder is capable of performing I 
 
 A. I do. 
 
 108. Q. Then, if any material part of the force of the powder should 
 be expended otherwise than in expelling the shot, for instance, in burst- 
 ing the gun, the shot would not be thrown so far, would it ? 
 
 A. Shot do go as far at times, about as far, when the gun bursts as 
 when it does not, and the forces are exerted simultaneously on the shot 
 and the gun. This gas, while expelling the ball is also bursting the 
 gun ; the ball gets its velocity in the gun about the same time the gun 
 reaches that strain when it must give way. There is no sudden enlarge- 
 ment of the capacity of the bore behind the ball until the gun gives 
 
EXPERIMENTS ON HEAVY ORDNANCE. 49 
 
 way. If the gases could expand the capacity of the bore behind the 
 ball suddenly, then the shot would not go as far ; but it does not do 
 that. The gun bursts when the bore enlarges. 
 
 109. Q. Would it reach its destined object ? 
 
 A. It will go just about as far and just about as straight. That is 
 the result of my observation. 
 
 110. Q. Then only a portion of the work the powder is capable of 
 doing is exerted on the shot ; the large amount of it being exerted on 
 the gun. 
 
 A. It is exerted on the shot, too. 
 
 111. Q. Do you think a Parrott gun would burst if the shot should 
 be fastened so as not to be moved from its home position ; that is, by 
 the direct pressure of the gas ? 
 
 A. Well, I do not know. I should think his large guns would ; but I 
 never saw it tried. 
 
 112. Q. Would it not be nearly all the work the powder could do to 
 burst the gun under such circumstances ? 
 
 A. Yes, sir ; I should think it would ; but it will do just as much 
 work towards throwing the projectile at the same time. 
 
 113. Q. Do you believe the powder capable of performing twice the 
 amount of work at one time it does at another I 
 
 A. No ; but I believe it capable of performing work in all directions 
 at the same time. That is the nature of gases, and of fluids too. 
 
 114. Q. Then there would be the same amount of force exerted in the 
 chamber of the gun whether the shot went out or not ? 
 
 A. Yes, sir ; the same amount of force developed. That comes from 
 the nature of gases ; the way gases exert themselves. 
 
 115. Q. There have been tables of ranges established for the Parrott 
 gun, I believe ; are they nearly correct ! 
 
 A. I think so. 
 
 116. Q. Have you ever known a shot to perform only one-fourth of its 
 range when all the conditions of loading were attended to properly, and 
 if so, did the gun burst at such time ? 
 
 A. 'I do not recollect any such case. 
 
 117. Q. Then the powder is shown, by the range of the shot, to be 
 nearly uniform in its action I 
 
 A. Yes. Well, the same powder would be under exactly the same 
 circumstances. I suppose that condition applies to all these questions. 
 The varying character of our powders, the difference in barrels from the 
 same lot, and the difference in portions of the same barrel, introduces 
 all sorts of elements of uncertainty in our firing. But I understand 
 these questions presuppose that the powder is of the same quality, and 
 ignited under the same conditions. 
 
 118. Q. The force of the powder being so nearly all expended in eject- 
 ing the shot, there could not be enough of its force spared from the ejec- 
 tion and projection of the shot to burst the gun at the same time and at 
 one operation ; consequently we must assume that the bursting is per- 
 formed a little at a time ? 
 
 A. If you establish the first part of that question as a hypothesis, I 
 do not exactly understand the condition of things in the bottom of a gun 
 when it is fired to be explained or stated in that question. I think that 
 the work of bursting and ejecting the shot from the gun goes on at the 
 same time, as my other answers indicate. 
 
 119. Q. And that when a shot is projected to the extreme extent that 
 it can be thrown, there is just as much force exerted to burst the gun ? 
 
 A. Certainly the gun is strained just as much. 
 Rep. No. 266 4 
 
50 EXPERIMENTS ON HEAVY OEDNANCE. 
 
 120. Q. What change have you noticed in the structure of the iron 
 of guns half an inch from the surface of the bore, which have been fired 
 no more than 300 rounds and then burst, and what in any gun fired more 
 than a thousand rounds I 
 
 A. I have never examined that very closely, so I have no intelligent 
 answer to give to that. It belongs more especially to fabricating ord- 
 nance. 
 
 121. Q. Then you have never known test pieces to be taken from the 
 surface of the bore of a gun that burst ? 
 
 A. Not under my direction ; it is done, I know, but I am not prepared 
 to give an intelligent answer to that. 
 
 122. Q. Do you think a Parrott 100-pounder could be permanently 
 enlarged in its calibre by bursting five shells at a time in the bore ? 
 
 A. Simultaneously I 
 
 123. Q. Yes, at one explosion. 
 
 A. No, 1 do not believe it would 5 not if there was no charge behind. 
 If there was a charge behind and wedging should take place, there might 
 be a permanent enlargement. I do not believe to explode the charges 
 in the shells would burst the gun. It might, though I should not think 
 it would. 
 
 124. Q. Then your theory is that w^hen the shell bursts in the gun, if 
 the gun bursts it is occasioned by the wedging of the shell. 
 
 A. Yes ; the gun may be weakened by being deeply scratched by frag- 
 ments of the shells, but the great strain on the gun when the shell bursts 
 in it comes from wedging. 
 
 125. Q. Do you think a Parrott 100-pounder could be broken in two 
 just forward of the reinforce band by a fair blow from the shot of another 
 gun of the same kind ; or would it require a number of shots to break 
 it? 
 
 A. I should think it might be broken or injured so that it would not 
 be fit for any service. It might be indented so as to reach clear through 
 into the bore. 
 
 126. Q. Have you an idea as to the depth of the indentation I 
 
 A. I think the gun might be permanently disabled by even one shot 
 fired against it at the chase. It might require more than one. 
 
 127. Q. Have you ever seen an indentation in the surface of the bore 
 of a Parrott gun which has burst, from which you could determine 
 whether the force with which the bursting shell had acted on the bore 
 had been sufficient to cause the rupture? 
 
 A. No, I never regarded the bursting of shells sufficient to burst Par- 
 rott guns. I have seen the effect on the bore of shells bursting in the 
 gun, but I never regarded it sufficiently serious to cause the bursting of 
 the gun unless repeated a great many times. 
 
 128. Q. Do you think the Parrott guns would burst if cast on the Eod- 
 man plan ? 
 
 A. I have always entertained the belief that they would be better if 
 cast on that plan, and I understood he did cast his guns, latterly, on that 
 plan. Indeed, I understood it was a condition imposed by the depart- 
 ment that he should cast them in that way, but I may be mistaken. 
 
 129. Q. Is it your opinion that would prevent their bursting I 
 
 A. I do not know. I think it would improve them, give them greater 
 endurance. 
 
 130. Q. Will you explain the advantage which the Bodman plan gives 
 in enabling a gun to resist the direct pressure of the powder ? 
 
 A. It puts the metal in that condition to bring its strength throughout 
 the entire thickness of the gun into play when it is fired 5 a portion of 
 it being under initial compression in the start. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 51 
 
 131. Q. Would a Rodman gun cast hollow and cooled from the interior, 
 or a solid cast gun of the same iron, model, and weight, be best able to 
 resist the breaking by unequal expansion, if a heated rod of iron should 
 be inserted in the bore ? 
 
 A. I should think the gun cast solid and bored out would stand the 
 introduction of the red-hot rod best. 
 
 132. Q. This tension would weaken the gun for resisting the expand- 
 ing force ? 
 
 A. I think so. 
 
 133. Would it be possible, in your opinion, to shrink the band on the 
 Parrott gun with force enough to reduce the diameter of the bore 1 
 
 A. I should not think it would be, but I have been told by those 
 engaged in making the guns that it actually takes place. 
 . 134. Q. Could the length of the bore be increased in any slight degree 
 by the shrinking of the band ? 
 
 A. I should think not. 
 
 135. Q. If the gun were made of India-rubber, and th e band were shrunk 
 on, would it increase the length of the gun ? 
 
 A. I think there is some doubt about whether it would. India-rubber 
 undergoes compression. I do not think it would necessarily increase the 
 length to compress it. It might a little. India-rubber is not much like 
 cast-iron, though India-rubber can be compressed without its dimensions 
 in a lateral direction undergoing any change. I should think in the case 
 of a tube, though violently compressed that way by a band shrinking on 
 it, it would elongate a little. 
 
 136. Q. If the band was so placed on the gun as to reduce the diam- 
 eter slightly, and if it should increase the length slightly also, and the 
 gun should then heat from the interior, would not the band be probably 
 strong enough to prevent radial expansion, and cause the interior of the 
 metal to flow towards the breech, and towards the muzzle under the 
 band? 
 
 A. Yes; that would be the tendency. 
 
 136. Q. If the cast iron beneath the band were hottest within the bore, 
 and had a gradually reduced temperature towards the outside, would 
 not the expansion of the inner metal lengthwise have a tendency to break 
 the outside, which would not expand so much ? 
 
 A. That is the tendency. 
 
 137. Q. Dp you not believe that it is easier to restrain the expansion 
 of a gun radially if you permit it to expand longitudinally? 
 
 A. Yes. 
 
 138. Q. Dp you think it would be possible to restrain the expansion 
 of the cast iron of a Parrott gun in all directions by any plan of an 
 adjusting band? 
 
 A. No ; nor any other gun. That does not apply to Parrottfs especially. 
 
 139. Q. If you doubted that the transverse fracture of the Parrott gun 
 was caused by the unequal heating alone, would you believe the heat 
 might cause tensions which would assist the force of the powder to break 
 the gun ? 
 
 A. Heat develops forces which would tend to break a gun. It is the 
 very first tendency for a gun to break in two when fired. 
 
 140. Q. If a strong current of hot gases should be brushing over or 
 across the surface of metal, do you think more heat would be communi- 
 cated to the same area of surface than would be if the heated gas were 
 merely pressing against the surface without currents for the same time 
 of exposure ? 
 
 A. I do not know, I am sure. 
 
52 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 141. Q. Is not the surface of the vent liable to receive more heat per 
 square inch on its surface according to the strength of the current, and 
 the length of time the current plays over it, than any other equal surface 
 of the bore of the gun ? 
 
 A. It is subject to greater wear. Whether a greater degree of heat is 
 evolved there I do not know. 
 
 142. Q. If the metal surrounding the vent for a radius of two inches 
 should be heated in this manner, a force would be exerted similar to that 
 which would be exerted if a hole four inches in diameter were made in 
 the gun with its axis coinciding with the axis of the vent, and a slightly 
 tapered bolt driven into it, would not the gun be liable to break trans- 
 versely at that point when the force of the powder came to act upon it ? 
 
 A. That would be the tendency. 
 
 By the CHAIRMAN pro tern. : 
 
 143. Q. Do you know whose 12-inch rifle projectiles were used against 
 the iron targets at Fortress Monroe on September 21 and 22, last year ? 
 
 A. They were called the Dyer projectile, with the Taylor sabot. That 
 is what we were informed down there. I was on the board. That is 
 what Colonel Baylor told me ; and Mr. Taylor was there to superintend 
 their use. 
 
 144. Q. You saw him there on the experimental grounds ? 
 
 A. Yes, sir; I understood from officers there the original sabot of 
 General Dyer had been improved upon by Mr. Taylor in its form and in 
 the composition. 
 
 145. Q. Did he explain to you the composition of the sabot he used in 
 the 12-inch projectiles ? 
 
 A. He explained the way it was attached ; and I remember I took a 
 memorandum of the different component parts of the composition. There 
 were copper, tin, and lead in it, and he gave me the proportions at the 
 time, I think, but I do not recollect what they were. 
 
 146. Q. Did the sabot metal take the grooves well? 
 A. Yery well, indeed. 
 
 147. Q. And did the firing exhibit accuracy? 
 A. Yes, sir. 
 
 148. Q. Can you give any opinion as to the value of the sabot com- 
 posed of that metal as compared with other kinds of sabots you have 
 seen? 
 
 A. I have no opinion with regard to the advantage of that peculiar 
 kind of alloy composition, though I know these projectiles worked as 
 well as if not better than any I ever saw used, and I presumed at the 
 time it was in consequence of having a very good sabot on. 
 
 149. Q. Will you look at the two diagrams, accompanying the patent 
 of Taylor's soft-metal sabot, and tell me whether the sabots which were 
 used with the projectiles at these experiments were figure 1 and figure 2.? 
 
 A. Figure 1 is a drawing representing what I suppose to be a Dyer 
 projectile, with the Taylor sabot on, or resembles the kind of projectiles 
 used in the experimental firing at Old Point Comfort in September, 1866. 
 The ordnance officers there informed me it was the Dyer projectile with 
 the Taylor sabot. The firing was accurate and satisfactory. Colonel 
 Baylor was the officer with whom I had the conversation. 
 
 150. Q. What advantage or disadvantage do you think there is in 
 having guns of different calibres with different ammunition for the army 
 and navy ? 
 
 A. It is a disadvantage, I think. 
 
 151. Q. Would there not be a very great simplifying of the arming of 
 
EXPERIMENTS ON HEAVY ORDNANCE. 53 
 
 the two arms of the service, and a very great mutual advantage, if it were 
 possible to use alternately the same guns and the same ammunition in 
 the army and in the navy ? 
 
 A. It would be better. I had occasion to borrow guns of the navy on 
 Morris Island. They happened to have the guns I wanted, and suited 
 the ammunition I had ; and it was a very great convenience. They were 
 Parrott guns. It would be an advantage if all the calibres corresponded 
 in the two arms of the service. 
 
 152. Q. Do you know of any other cases within your experience where 
 there might have been an interchange of arms or ammunition if the cali- 
 bres had been the same in the army and navy ? 
 
 A. Cases of that kind would only occur in joint expeditions like the 
 one I was connected with. I do not recollect any other case. 
 
 Extract from testimony of Brigadier General A. B. Dyer. 
 
 JANUARY 18, 1868. 
 
 By Mr. BUTLER : 
 
 ###*### 
 
 1. Question. What is the amount that is paid, either in percentage or 
 in gross, as you may remember, to General Eodman ? 
 
 Answer. I do not know that anything has been paid. I have no 
 knowledge of any amount having been paid. 
 
 2. Q. As a royalty on his gun ? 
 
 A. None at all. I have answered that question in writing as fully as 
 I could. 
 
 3. Q. That may be, sir. 
 
 A. I have no knowledge whatever of the matter. 
 
 4. Q. Have you any knowledge whatever that the price of guns of the 
 Eodman pattern has in any way been increased because of his royalty, 
 or because of any sums to be paid on account of his patent, directly or 
 indirectly? 
 
 A. I have understood that there was a royalty entering into the price 
 of the gun. 
 
 5. Q. How many hundred thousand dollars' worth, within bounds, have 
 you ordered of the Eodman gun since you have been Chief of Ordnance? 
 
 A. I do not remember. 
 
 6. Q. Many hundred thousands? 
 A. Yes. 
 
 7. Q. Amounting to millions? 
 
 A. I do not know whether amounting to millions or not. 
 
 8. Q. Do you mean to say that in ordering many hundred thousand 
 pounds, amounting to millions, perhaps, of the Eodman gun, you never 
 inquired as to whether the price was increased by a royalty or not? 
 
 A. I knew that the price was increased by a royalty. 
 
 9. Q. Did you not inquire how much? 
 
 A. I had seen it in print in the testimony taken before the Com- 
 mittee on the Conduct of the War. The price was one cent per pound. 
 
 10. Q. Did not you inquire otherwise than what you saw in print? 
 A. No, I am not aware that I ever did. 
 
 11. Q. Then, in contracting for many hundred thousand dollars' worth 
 of ordnance, you made no inquiry except what you saw in the printed 
 testimony taken by the Committee on the Conduct of the War as to 
 whether the price was increased by a royalty paid to an officer of the 
 ordinance department ? 
 
54 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 A. I never knew that this was paid to an officer of the department. 
 
 12. Q. Or because of a patent given an officer of the department ? 
 A. I had understood this, and I did not make any further inquiries; 
 
 had understood several years ago that this entered into and constituted 
 a part of the cost. 
 
 13. Q. What proportion of the cost of a piece of heavy ordnance 
 would one cent per pound be as an average? 
 
 A. Something like one-twelfth, I suppose. 
 
 14. Q. What have you paid a pound, on an average, for the Hodman 
 guns? Give me the extreme limits, the lowest and the highest, since 
 April, 1861. 
 
 A. I should have to refer to my report, which will probably show. 
 
 15. Q. Can you give me approximately the limits ? 
 
 A. No ; I do not remember what w^as paid in the early part of the war 
 for them. I can tell you the later prices that have been paid. 
 
 16. Q. In the early part of the war as low as six or eight cents? 
 
 A. Yes, I think probably in the early part of the war as low as six or 
 eight cents. 
 
 17. Q. Now paid ? 
 
 A. I think about twelve cents. 
 
 18. Q. Then it would vary from one-sixth to one-twelfth I 
 
 A. If it had been as low as six and as high as twelve yes, I should 
 think so. 
 
 19. Q. Did you understand that this royalty or patent had been pur- 
 chased by Mr. Knap ? 
 
 A. I did. . 
 
 20. Q. Did he make all the Rodman guns I 
 A. He did not. 
 
 21. Q. Who did? 
 
 A. They were made by Mr. Knap; by the South Boston foundry, 
 (Alger & Co. ; ) by the Eeading (Pa.) foundry, (Seyfort, McManus & Co.; ) 
 and by Mr. Parrott. 
 
 22. Q. Were not all those guns increased in price by the royalty? 
 A. I have no doubt of it, sir. 
 
 23. Q, And the makers had all to pay this royalty, which they added 
 to the other cost of the gun? 
 
 A. I know nothing whatever of that. 
 
 24. Q. Do you know of any arrangement by which they did not have to 
 pay it? 
 
 A. I know neither one thing nor the other in regard to that. 
 
 25. Q. I find from your report that the amount paid for Rodman guns 
 is $2,636,600, up to June 30, 1866 ? 
 
 A. Yes, sir. 
 
 26. Q. Did not you know Mr. Rodman was interested one-half in that 
 royalty ? 
 
 A. I had no other knowledge than from hearsay j I believed it. 
 
 27. Q. That he had one-half? 
 A. I believed he had one-half. 
 
 28. Q. Estimating the royalty at an average of one-tenth the cost, the 
 whole amount of royalty paid on those guns would be $263,660. That 
 was so, was it not? 
 
 A. You made the calculation ? 
 
 29. Q. Will you not see if I am right ? 
 A. I believe so. 
 
 30. Q. This is up to June 30, 1866. How many of those guns have 
 been purchased since? 
 
EXPERIMENTS ON HEAVY ORDNANCE. 55 
 
 A. I do not remember, sir. 
 
 31. Q. Are they still being purchased? 
 A. They are not. 
 
 32. Q. When did it cease? 
 
 A. I think no orders have been given. 
 
 33. Q. When did they cease being purchased? Giving orders might 
 be one thing, and purchasing another. They might be received in ful- 
 filment of old orders ? 
 
 A. I think the last deliveries were made somewhere about a year 
 ago a little more or a little less a little less, I think. 
 
 34. Q. I find in the last report of the Secretary of War the following : 
 
 A board of engineer, ordnance, and artillery officers, specially appointed to consider this 
 
 the calibre of 13, 15, 
 
 A board ot engineer, ordnance, and artillery officers, specially appoi 
 subject of arming the permanent forts, reported the 1,915 pieces of th 
 and 20 inches for smooth-bores, and of 10 and 12 inches for rifles, were required for the per- 
 manent fortifications, and should be provided, and their report was approved by the Secre- 
 tary of War. None of these guns have yet been provided. There are no orders or contracts 
 existing for heavy cannon. This stoppage of the procurement of heavy cannon has been 
 mainly occasioned by "persistent efforts for some time past by ignorant or designing persons 
 to destroy public confidence in the heavy guns which have been provided for the ordnance 
 departments of the army and navy." 
 
 This*language, "persistent efforts for some time past by ignorant or 
 designing persons to destroy public confidence in the heavy guns which 
 have been provided for the ordnance departments of the army and navy," 
 is quoted by the Secretary of War from the report of the Chief of Ord- 
 nance? 
 
 A. Yes. 
 
 35. Q. To whom, sir, did you refer in that report? 
 
 A. I referred to the articles which were published in the newspapers, 
 as I state, from time to time. I should like to read that portion of my 
 report. 
 
 36. Q. We have not been able to get a copy. That is taken from your 
 report, is it not? 
 
 A. That is from my report. 
 
 37. Q. When you say, in your report, "persistent efforts" have been 
 made u for some time past by ignorant or designing persons to destroy 
 public confidence in the heavy guns which have been provided for the 
 ordnance departments of the army and navy," you refer to articles which 
 appeared in the newspapers? 
 
 A. Yes, sir; and to specimens of iron castings which are exposed 
 here in the old hall of representatives. 
 
 38. Q. To anything else? 
 
 A. I am not aware that I referred to anything else ; do not remember 
 that I did ; but those I mainly referred to. 
 
 39. Q. Did you stop the business of the ordnance department in arm- 
 ing the fortifications because of articles in newspapers, and because of 
 the exposure of the iron castings in the old hall of representatives in the 
 Capitol? 
 
 A. I did not stop on that account at all. The engineers, or the chief 
 engineer, asked for certain heavy guns about a year or more ago. Some 
 of those guns were guns which had not been adopted, were not of the 
 models that had been adopted for the arming of the forts, and I, upon 
 consulting with him, asked that a board of officers might be appointed 
 engineer, artillery, and ordnance officers for the purpose of considering 
 the question of the armament of the forts and determining what guns 
 were required ; and I stopped procuring guns, or declined to give any 
 orders for guns, until this board had reported and their report had been 
 approved by the Secretary of War and the guns ordered. 
 
56 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 40. Q. Is that the "board of engineer, ordnance, and artillery officers 
 specially appointed to consider the subject," referred to here? 
 
 A. That is the board referred to there. 
 
 41. Q. Do I now understand you to say you did not stop until a board 
 was ordered and they had recommended, and their recommendation had 
 been approved by the Secretary of War? Hew do you explain, then, 
 that immediately following you say: "This stoppage of the procurement 
 of heavy cannon has been mainly occasioned by i persistent efforts for 
 some time past by ignorant or designing persons to destroy public con- 
 fidence in the heavy guns which have been provided for the ordnance 
 
 . departments of the army and navy?'" 
 
 A. "This stoppage of the procurement ; n I am not aware that I said 
 that. 
 
 42. Q. "By persistent efforts?" 
 
 A. I am not aware that I ever said it. 
 
 43. Q. Have you received your report in print? 
 A. Yes, sir. 
 
 44. Q. I pass from this, then, till I can get your report. 
 
 # # * * '# * * 
 
 45. Q. To return, now, to this question of heavy ordnance : Is there 
 any authority for saying that the arming of the forts has been stopped 
 mainly because of these publications in the newspapers and the exhibi- 
 tion of these castings in the old house chamber? 
 
 A. I am not aware that I have said it. 
 
 46. Q. That is not the question whether you have said it. The 
 question is, whether it is a fact? 
 
 A. No. I do not know that it is a fact. 
 
 47. Q. Then there is no authority for saying that? 
 A. May I ask whether you supposed I had said so? 
 
 48. Q. I supposed so for this reason 
 
 A. That does not appear to be in quotation marks, and what purports 
 to come from my report. 
 
 49. Q. I want to ascertain if it is truje, being said by anybody else ; 
 because it is put forward that ignorant and designing persons have 
 stopped the arming of the forts; and, if it is true, it is time those 
 persons got out of the way and the armament of the forts went on. 
 Somebody said it, evidently ; and the statement is sent to us for our 
 information by Congress. Now, I think it is fair for you to say that you 
 have not said it. I have now here your report ; all you have said is this : 
 
 Persistent efforts have been made, for some time past, by ignorant and designing persons, 
 to destroy public confidence in the heavy guns which have been provided for the ordnance 
 departments of the army and navy. 
 
 Iron castings, placarded as representing the condition of the metal in our heavy guns, 
 have been placed in conspicuous public places, and publications have appeared from time 
 to time, in prominent journals, asserting that these guns were worthless, that they could 
 only be fired with very light charges of powder, and that they would burst if fired a few- 
 times rapidly. 
 
 But you nowhere say here that you have stopped on that account ? 
 A. I told you I was not aware of saying it. 
 
 50. Q. At any rate, you are certain you never did? 
 
 A. I am not aware that I ever did on that account. I do not know 
 what the Secretary of War may have done. 
 
 51. Q. He could not have done anything of that sort without your 
 knowledge without its coming through you? 
 
 A. He gave me an order, last spring, to procure no more heavy guns 
 without his further authority. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 57 
 
 52. Q. Did you understand that order to be in consequence of a reso- 
 lution from this committee 1 ? 
 
 A. I believe that it was in consequence of it. 
 
 Extract from the statement of General Dyer, February 5, 1868 : 
 
 It is true, as stated by Mr. Wall in his testimony, that some Rodman guns have been 
 accepted and paid for before being fired ; but no gun has been accepted and paid for which 
 did not fulfil all the conditions required by the contract, and it is confidently believed that 
 no better guns have been furnished the government than are all of the heavy guns which have 
 been procured since I came into the bureau. 
 
 The ordnance department, through its constructor of ordnance, determines the kind of 
 metal which shall be used, and fixes the limits of tenacity, density, and initial strain, and 
 the character of the fracture of the metal. Specimens have been taken from every gun, and 
 no gun has been accepted the metal of which had not been prouounce^by the constructor of 
 ordnance to be entirely satisfactory. It is believed that a larger proportion of guns have 
 been condemned under the rigid system of tests which have been established by the depart- 
 ment than were formerly condemned when the guns were subjected to a severe powder proof. 
 To the best of my recollection and belief every Rodman gun made for the ordnance depart- 
 ment at the Fort Pitt foundry, Reading foundry, and the West Point foundry, has been fired 
 three times at the foundries, and not one has failed under the powder proof. As there was 
 no suitable proving ground at South Boston foundry, the 15-inch Rodman guns which were 
 made there, and which are known to be equal to the very best guns of the kind which have 
 been made, were not subjected to powder proof at the foundry, nor was it considered neces- 
 sary ; and as the founder was held responsible for the quality of the metal, as determined by 
 tests prescribed by the department for the soundness of casting and for the correctness of 
 the dimensions of the finished gun, and not for the result of the tiring, the tiring was deferred 
 until the guns should be mounted in the forts. Not one 15-inch army gun has ever burst, 
 and some of them have been fired with twice the quantity prescribed for the proof of such 
 guns. Oue gun, taken without selection from those made at South Boston foundry, and not 
 before proved by firing, has been fired more than 250 times, upwards of 130 rounds being 
 with 100 pounds of powder and solid shot. 
 
 I never directed Mr. J. C. Wall not to prepare copies of the inspection reports of cannon 
 for j'our committee. I always intended to furnish them, and, as far as I could, all other 
 iuformation which was called for by the committee, as is well' known to General Maynadier, 
 Colonel Tread well, and Major McGinness, officers on duty in the bureau, and to Mr. Keller, 
 Mr. McNally, Mr. Williams, and the other clerks in the bureau, who have been employed 
 under their direction in preparing the information called for by the committee. I am very 
 confident that all of these gentlemen will testify that my instructions have been to prepare 
 full, complete, and true answers to all the questions asked by the committee. 
 
 WASHINGTON, D. C., January 25, 1868. 
 
 Professor, E. "N. HORSFORD, of Cambridge, Massachusetts, sworn and 
 examined : 
 
 By Mr. BUTLER : 
 
 1. Q. What is your profession or business occupation? 
 
 A. I have been a professor in Harvard College, until within two or 
 three years, for the previous sixteen years. 
 
 2. Q. Have you had such experience as would lead you to have a 
 knowledge of gunpowder and its effects on iron ? 
 
 A. I have made some experiments with a view of determining the tena- 
 city of iron when subjected to the pressure of burning gunpowder. Shall 
 I go on to state the experiments? 
 
 3. Q. You may do so briefly. 
 
 A. I prepared short barrels by cutting off sections of Sharpens rifle 
 barrels, and fitted them with screw-thread plugs at each end of these 
 short barrels, as a preparatory step to my experiments. The plugs were 
 fitted as male screws, with counter-sunk shoulders, so that with the aid 
 of a wrench and vice I could bring the plugs home to the face of the end 
 of the barrel, there being an inch in length of the interior of my short 
 cylinder for gunpowder. In one of the cylinders I placed (the cavity 
 
58 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 being an inch in length) half an inch of loose rifle powder ; that is, half 
 filled the cavity. In another I quite filled the cavity. In a third I pat 
 in gunpowder compressed in the cylinder, two volumes in one. When 
 all the plugs were driven home, I threw the three cylinders into the fire. 
 After an interval of a few minutes, one of the cylinders gave a report ; 
 and a little later, another gave a report ; and there was no further report 
 that is, one of them did not give any report. I took these cylinders from 
 the factory to my laboratory, took out the plugs and found only sulphide 
 of iron (a compound of sulphur and iron) coating the interior of each 
 cylinder up to the point where the plug and the cylinder fitted to each 
 other. From that point, out along the line of the screw-thread, there 
 was in every case a channel, making the screw-thread thereafter fit 
 loosely. The surface of this channel (it being understood that the male 
 and female screws originally fitted with very great precision) was coated 
 with a compound of sulphur and iron. I found this to be true in all of 
 the cases, the channel deeper (more of the metal having been removed) 
 in the case of the compressed gunpowder than in the case of either of 
 the other two. I repeated these experiments in my laboratory, suspend- 
 ing the cylinder immediately after the explosion in water. Under such 
 circumstances, the surface of the cylinder was immediately coated with 
 myriads of minute bubbles. I then suspended the same cylinder, after 
 another experiment, in a solution of lime water, and found that, from each 
 of these points where the bubbles had before appeared, a stream of fine 
 white powder descended to the bottom of the vessel containing the lime 
 water. This was proof that carbonic acid came from the pores of the 
 metal. I found the exterior surface of the iron also to contain sulphur 
 in combination with the iron. I found in an experiment with a piece of 
 firing apparatus, devised by Professor Treadwell, where gunpowder was 
 exploded under pressure, that the sulphur came through the iron and 
 appeared at the surface, as in my experiments with the short barrels. 
 From these experiments, as well as from the fact, familiar to all artil- 
 lerists, that the vent of a cannon constantly increases in diameter under 
 firing, I drew the conclusion that the sulphur of the gunpowder under 
 pressure and under the influence of heat, in a degree leaves the saltpetre 
 and the charcoal of the gunpowder, and enters into combination with the 
 iron, forming a compound at the surface of the iron eminently fusible, 
 which, in the current of gases escaping through the vent-hole, or wher- 
 ever there is a current of gas at the instant of the combination of the 
 sulphur with the iron, strips this molten sulphide of iron off, enlarging 
 the vent. 
 
 4. Q. Did these various experiments which you have described lead you 
 to an opinion as to the cause of the burning out of the iron in the bottom 
 of the bore of cannon, as well as at the vent? 
 
 A. It led me to form an opinion as to the cause of the cavity which 
 has been described to me as having been formed in some wrought-iron 
 guns which have been subjected to experiment within the last three or 
 four years guns made by Mr. Ames. 
 
 o. Q. Was the cause of the formation of that cavity the same as of the 
 enlargement of the vent of the guns? 
 
 A. It is well known that if gunpowder be subjected to heat under 
 pressure even without pressure the sulphur may be all distilled from 
 the saltpetre and the charcoal, leaving the saltpetre and charcoal quite 
 pure. I conceive that under pressure, in the experiments which I made, 
 the sulphur was distilled in part without entering into combination to 
 form sulphuric or sulphurous acids. In the case of the cannon, to which 
 the question refers, I conceive, as a resultant of the forces brought into 
 
EXPERIMENTS ON HEAVY ORDNANCE. 59 
 
 play, there would be, at the instant of the explosion of the cartridge, 
 along the axis of the gun and towards the cascable, something like a jet 
 of gaseous sulphur, which, striking the metal, would act to accomplish 
 the same effect that is produced in the vent; that is, a stream of sulphur 
 vapor, playing upon a surface of iron, forms a compound the instant the 
 sulphur strikes the metal ; which compound, being fusible at a low tem- 
 perature, is stripped from the surface as fast as formed, and so long as 
 the stream is kept up. This jet would excavate a hole in the direction 
 of the axis. This action would be more 'energetic at the commencement 
 of the explosion of the gunpowder than after the ball has left its seat 
 at any rate, after some considerable expansion of the products of com- 
 bustion has taken place. 
 
 6. Q. Would increasing the pressure of the powder increase its effect 
 in producing this result? 
 
 A. The increase in pressure, retarding the escape, and so keeping the 
 sulphur there longer, to produce its effect, would accomplish that end. 
 
 7. Q. What is the difference in the bursting strain on a cannon charged 
 with powder giving a pressure, say, of 87,000 pounds to the inch, and of 
 powder giving but 35,000 pounds, pressure ? 
 
 A. The ratio is as the square. If 35 gave you a pressure of 1, 70 
 would give you a pressure of 4 ; 87 would be somewhere about 5. 
 
 8. Q. So the pressure in the first case, with powder exerting a pressure 
 of 87,000 pounds to the inch, would be about five times as great, you say, 
 as of powder with a pressure of 35,000 pounds ? 
 
 A. Yes, sir ; about that. 
 
 9. Q. Having two guns of equal calibre, firing equal weights of powder, 
 one of them being observed to be excavated at the bottom of the bore, in 
 form of a comparatively slender tube or cylinder a long irregular cylin- 
 drical cavity to what should that difference in the effect be ascribed? 
 
 A. To the greater strength of the gunpowder, inasmuch as a more 
 powerful jet of sulphur would be brought to play upon the bottom of the 
 chamber in the line of the axis than would be with a powder of less 
 strength. 
 
 WASHINGTON, D. C., February 20, 1868. 
 ISAAC FRENCH sworn and examined. 
 By the CHAIRMAN : 
 
 1. Q. Please give your name in full? 
 A. Isaac French. 
 
 2. Q. Give your age, residence, and occupation ? 
 
 A. I am 53 years of age ; I reside in Salisbury, Connecticut, and I am 
 a blacksmith or hammerman by trade. 
 
 3. Q. Are you familiar with the working of iron? 
 A. I am. 
 
 4. Q. How long have you been engaged in that business ? 
 A. Nearly 40 years. 
 
 5. Q. Do vou know Mr. Horatio Ames ? 
 A. I do. 
 
 6. Q. Have you been in his employ at any time? 
 A. I have worked for him about 30 years. 
 
 7. Q. In what capacity ? 
 
 A. As a blacksmith, hammerman, or heater, and other things. 
 
 8. Q. Were you in his employ at the time he made the 11 100-pounder 
 guns for the government ? 
 
60 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 A. I was. 
 
 9. Q. Were those guns made under your immediate personal inspec- 
 tion If 
 
 A. Yes. 
 
 10. Q. During all the different stages of their manufacture f 
 
 A. Yes ; I did a good share of the work myself. It was all done under 
 my notice. 
 
 11. Q. Will you state briefly the manner in which the guns were manu- 
 factured, beginning with the mode of making each ring, and then the 
 putting the rings together and forming the gun ? 
 
 A. In the first place the iron is puddled ; that is, put into a furnace 
 and melted, and then it is stirred and worked in a manner similar to the 
 churning of butter, until it finally can be gathered into a ball, when it 
 is taken out in the form of a large ball and put under a hammer and 
 beaten into plates about four or five inches wide and 18 inches long. 
 Then we put three or four of them together and draw them out into a 
 bar about five and a half inches wide and three to three and a half feet 
 long. Then we cut these into three pieces and pile one piece upon the 
 top of the other. Then we draw them out into what we call a slot, 
 about two feet and a half long and eight inches wide. Then we take 
 them to the hammer, and pile them up on what we call a porter-bar, 
 when they are heated and drawn out into bars for rings, six inches 
 square. That is one kind of ring. There are three or four different 
 kinds. But that is the process and way of working the iron. Then the 
 ends are cut off, and they are put into a furnace and heated and bent 
 around into a ring. They are then taken to a blacksmith's fire and 
 welded together ; then to the machine shop, and the inside is bored out 
 to ten inches in diameter and so as to leave them perfectly smooth on 
 the inside. The face is also turned off smooth. That is the process of 
 making the middle ring of the cylinder of the gun. The iron for the 
 inside ring is made in the same way and put together in the same way, 
 only the ring is larger, being drawn 8 by 10 inches. Then they are 
 slotted off and a hole four inches in diameter is bored through them. 
 They are then put on a mandrel or arbor and turned off so as to be 10 
 inches in diameter. Then they are nicely fitted into this other ring that 
 I have described. 
 
 For the cylinder of the gun we have another ring still, outside of this, 
 six inches by three. That is shrunk on to the other two. That forms 
 the rings 5 and that is all I can say about that. There were three rings 
 thus, one inside of the other. The middle ring, which is ten inches in 
 diameter, projects about five-eighths of an inch from the other on the 
 side that goes on to the gun. The object of the projection is to have it 
 strike in the centre of the weld, the centre of the gun, first. 
 
 We have what we call a porter bar, and on the end of this porter bar 
 we form a lump for the breech, about 15 inches in diameter. Then we 
 weld a ring around that, nine inches by three and a half, and another 
 we have a horizontal hammer, by which we upset this and make it square 
 ring around that, three by six. That forms the breech of the gun. Then 
 on the end, or a little oval. Then that is heated in one furnace and the 
 ring in another. Then we fetch the gun out of one of the furnaces by 
 this porter bar, and place it in a large groove, under a big steam hammer. 
 We fetch the ring out of another furnace with a large pair of tongs and 
 place it right against the end of the gun. Then this horizontal hammer 
 which I have spoken of strikes against it and butts it up to weld it on. 
 There is a blocking behind the porter-bar that holds it fast, and keeps 
 it from going back. Thus we keep putting on rings until the gun is long 
 
EXPERIMENTS ON HEAVY ORDNANCE. 61 
 
 enough ; but when we get past the cylinder of the gun we have only two 
 rings. 
 
 12. Q. The strength of the gun depends upon the perfection of the 
 welds ? 
 
 A. Yes, of course. 
 
 13. Q. From your experience in making these guns, is it your opinion 
 that, with proper care you can produce reliable and perfect welds I 
 
 A. Yes, we can, just as well as in any other way in the world. 
 
 14. Q. When the weld is properly made, is perfect, is there any weak- 
 ness at the welding point ? 
 
 A. I do not see why there should be any more than at any other part 
 of the gun. 
 
 15. Q. Is it as strong there as at any other portion of the gun? 
 A. I do not see why it is not. 
 
 16. Q. Did you have any failure to make the welds, during your expe- 
 rience ? 
 
 A. No, not on the guns that I made. 
 
 17. Q. Did Mr. Anies, in making any guns, fail in making a weld at 
 any time ? 
 
 A. We tried various experiments, and sometimes the welds were not 
 perfect. 
 
 18. Q. But after the system was perfected you think the welds were 
 such as could be depended upon ? 
 
 A. I think the eleven guns were perfect welds, and were as solid there 
 as any where. 
 
 19. Q. And you say you saw those guns during every step in their 
 manufacture, so that you have perfect knowledge of them? 
 
 A. Yes ; I saw the iron from the pig until they were finished. 
 
 20. Q. Are you confident there was no defect, owing to carelessness ? 
 A. I took every pains possible, and saw every ring put on. 
 
 21. Q. What was the character of the iron used ? 
 
 A. I think it was the best iron I have ever worked Salisbury iron ; I 
 never worked any that would stand the heat as well. 
 
 22. Q. Is it superior in certain qualities ? 
 
 A. Yes; some iron when a little over-heated has its welding power 
 destroyed. But the Salisbury iron is not so 5 and if hammered a little it 
 can be brought back to its original nature. 
 
 23. Q. Have you any personal interest in this claim of Mr. Ames? 
 
 A. I have not any more than my daily wages. I have worked 30 years 
 for Mr. Ames, and he has never given me any bribes. 
 
 24. Q. Then you have not now any interest in it ? 
 
 A. No, only if he makes guns and I work for him, he will pay me. 
 
 WASHINGTON, D. C., February 20, 1868. 
 Mr. JAMES WILSON sworn and examined. 
 By the CHAIRMAN : 
 
 1. Q. Please give your name and residence. 
 
 A. My name is James Wilson; I reside in Washington. 
 
 2. Q. What is your occupation ? 
 
 A. Foreman and forger, at present, at the Washington navy yard. 
 
 3. Q. Do you know anything about these wrought-iron guns which 
 Mr. Ames made for the Navy Department ? 
 
 A. No. 
 
62 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 4. Q. Have you ever seen them made? 
 A. No. 
 
 5. Q. Are welds, when perfectly made, as strong as any other part of 
 the iron f 
 
 A. Yes ; I think they are quite as strong. 
 
 6. Q. What is your opinion about the possibility of making perfect 
 welds in large masses of iron, if you have suitable tools and furnaces ? 
 
 A. I think you can do it and make them perfect. 
 
 7. Q. You have heard the system of manufacture described here of 
 Mr. Ames's guns ? 
 
 A. Yes. 
 
 8. Q. Will you state if you have any doubt that the welds could be 
 made perfectly by that system ? 
 
 A. I have no doubt in the world ; I believe it can be done. 
 
 9. Q. Then you think there is no reason why large masses of iron 
 should oxidize so as to prevent welding, if only skilfully and properly 
 manipulated ? 
 
 A. None in the world. 
 
 10. Q. Will not large masses of certain iron be longer in oxidizing 
 than smaller quantities, owing to the greater amount of the heat ? 
 
 A. No ; I do not think they would. 
 
 11. Q. Do you think that would be in proportion to the surface pre- 
 sented 1 
 
 A. Yes, I do not see any difference in that respect between a large 
 and a small piece. 
 
 WASHINGTON, D. 0., February 20, 1868. 
 WILLIAM W. BRADLEY sworn and examined. 
 By the CHAIRMAN : 
 
 1. Q. Please give your name, residence and occupation. 
 
 A. My name is William W. Bradley ; I reside in Washington, I am at 
 the present time clerk in the ordnance department ; I am a machinist 
 by trade. 
 
 2. Q. Did you in the summer of 1865, by direction of the ordnance 
 department, carry to Mr. Horatio Ames drawings for the rilling of two 
 guns ? 
 
 A. I went by the direction of the ordnance department, but I do not 
 think I took the drawings ; I think Mr. Thomas, Mr. Ames's foreman, 
 took them. 
 
 3. Q. Will you describe the drawings I How many different kinds of 
 rifled guns were there ? 
 
 A. Two. 
 
 4. Q. What were they ? 
 
 A. One with the ordinary square rifling 5 the other was one of Brooks's 
 rifling. 
 
 5. Q. How long wer you at Mr. Ames's works ? 
 
 A. I got there on the 6th of July, and I left, I think, on the first of 
 August. 
 
 6. Q. Did you have opportunities of observing the manufacture of 
 guns ? 
 
 A. I did, perfectly ; I took a great interest in it, and saw everything. 
 
 7. Q. What was your opinion of the value of that system, for making 
 strong guns? 
 
EXPERIMENTS ON HEAVY ORDNANCE. 63 
 
 A. I think it was a most admirable system, the best I ever saw ; that 
 if iron cannot be put together by that system, there is none by which it 
 can. 
 
 8. Q. The whole question is whether welds could be made perfectly 
 by that system. Do you think they could ? 
 
 A. Yes, I think the plan of presenting the convex surfaces is the true 
 one, and that thus all the scoriae is forced out by the horizontal hammer. 
 
 9. Q. Were you in the battle of Fort Fisher ? 
 A. I was. 
 
 10. Q. Did any guns burst there to your knowledge, on board our fleet ? 
 A. Yes, but not on the vessel on which I was, but on some in the 
 
 vicinity. 
 
 11. Q. Did you understand^ that after guns burst the charges were 
 reduced ? 
 
 A. I think the order was to reduce to eight pounds, the vessel to which 
 I was attached had a 100-pouiider, but it was taken and laid aside and 
 never fired after. 
 
 12. Q. Was it the opinion that the excessive charging was the cause 
 of the bursting ? 
 
 A. There were many opinions expressed; some had one and some 
 another 5 I had my own opinion. Some thought it was on account of 
 the construction of the gun, and some that it was owing to excessive 
 charging. 
 
 13; Q. Was the efficiency of the guns reduced by lessening the 
 charge ? 
 
 A. The efficiency, of course, depends upon the power behind the pro- 
 ectile j if you diminish the power you diminish the efficiency, of course. 
 
 14. Q. What was the efficiency of these guns with the eight-pound 
 charge f 
 
 A. I never saw any experiment with an eight-pound charge ; but my 
 own experience would demonstrate that if it would take a lull charge to 
 keep the shot or shell point on, and not have a rotary motion, by dimin- 
 ishing it, it would not go point on, but would have a tendency to turn 
 oft'. 
 ' 15. Q. Did you see any of those guns after they were burst? 
 
 A. Only small fragments of the gun on board the Ticonderoga. 
 
 16. Q. What was your view of the cause of their bursting? 
 A. I think the guns were improperly made. 
 
 17. Q. How? 
 
 A. I do not think cast iron is capable of bearing such an immense 
 strain. The strain being brought on the cast iron the hoop is all that 
 holds it. 
 
 WASHINGTON, D. C., January^ 25, 1869. 
 
 Brevet Brigadier General T. J. KODMAN sworn and examined. 
 By the CHAIRMAN : 
 
 1. Q. Have you in any way the superintendence of the construction of 
 ordnance in the War Department 1 
 
 A. I am constructor of ordnance of the ordnance department. 
 
 2. Q. Are you the inventor of what is known in the ordnance depart- 
 ment as the Rodman system of fabricating cannon ? 
 
 A. Yes. 
 
64 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 3. Q. At what time did you originate this system? 
 A. In 1845, I first commenced it. 
 
 4. Q. When was it adopted by the War Department ? 
 
 A. I think it can be said to have been first adopted in 1862. 
 
 5. Q. When by the navy I 
 
 A. I do not know that it has been adopted by the Navy Department, 
 except for 12-inch rifles, 15-inch or larger smooth-bore guns. 
 
 6. Q. At what foundries have guns been made upon your system ? 
 A. The first guns were made at the Fort Pitt foundry. They were 
 
 then made at South Boston, 0. Alger & Co. ; at the Scott foundry, Bead- 
 ing, Pa., Seyfort, McManus & Co.; and at Mr. Parrott's, Cold 'Spring, 
 N. Y. There was one other that started to make, at Providence, R. I., 
 Builder's iron foundry. No guns were received from them for the ord- 
 nance department. 
 
 7. Q. Who are or have been the proprietors at the Fort Pitt foundry 
 since your guns have been made? 
 
 A. When I first started it was Knap & Totten ; it was that firm that 
 made the first experiments to determine the practicability of casting 
 guns in that way. Charles Knap's Nephews was the style of the firm 
 during the war. That firm is now the Knap Fort Pitt Foundry Company. 
 
 8. Q. Do you know whether any officers of the government have been 
 interested in that foundry ? 
 
 A. None, to my knowledge. 
 
 9. Q. What royalty, per cent., or profit have you received on guns 
 made according to your system ? 
 
 A. In the first place, I sold to Mr. Knap my interest in the patent, 
 for which he was to pay me one-half cent per pound on all castings 
 made under that patent, and on which he collected royalty. 
 
 10. Q. That contract still remains in force I 
 A. Yes. 
 
 11. Q. Can you state what has been about the gross amount of such 
 profit received by you ? 
 
 A. I could not state it exactly. 
 
 12. Q. Can you tell what was the prices -charged the government at 
 the different foundries for this gun ! 
 
 A. No, I cannot. That is on record in the Ordnance Office. I never 
 had anything to do with the prices paid for guns. 
 
 13. Q. Will you now explain what it is in your system that you claim 
 as original, and for which you receive a royalty ? 
 
 A. My recollection is, that my claim reads something like this: " For 
 the cooling of heavy hollow castings, intended to resent central force, by 
 circulating within the core a cooling fluid or gas; in combination with 
 the application of heat on the exterior to prevent too rapid cooling from 
 without." 
 
 14. Q. In what particular does your system differ from the system, 
 upon which was made the 12-inch coluinbiads of Colonel Boinfordf 
 
 A. It differs in this, that the gun cast by him was cast solid, and 
 cooled entirely from the exterior ; while guns cast on my system are 
 cast hollow, and cooled in accordance with my aforesaid claim. 
 
 15. Q. Will you explain the manner in which guns are made upon 
 Admiral Dahlgren's system ? 
 
 A. I do not know that Admiral Dahlgren has any system of casting 
 guns; he has a model and no other claim that I know of; his guns hav- 
 ing been cast solid, or cooled from the exterior, which is no novel method 
 of cooling. 
 
 16. Q. What are the general points of difference of models between 
 the Eodman and the Dahlgren guns ? 
 
EXPERIMENTS ON HEAVY ORDNANCE. 65 
 
 A. In theDahlgren gun the reinforce for two or three feet between the 
 breech and trunnions is cylindrical ; his gun then tapers rapidly to a 
 cone, the chase being conical j while in my model there is no straight 
 line on the exterior at all ; his cylinder being replaced by a double con- 
 vex surface, and his conical chase by a concave surface ; my model being 
 so constructed that, under the formula for the exterior, the chase may 
 be continued to any extent and leave a proper thicknesss of metal ; 
 while in the other the chase being extended the thickness becomes 
 nothing a short distance from the muzzle ; the taper between reinforce 
 and chase being much less rapid in my model than in his. 
 
 17. Q. What is the condition of the metal in guns cast upon your 
 system ? 
 
 A. That depends upon the rate of cooling from the interior. The 
 intention is, when the requirements are carried out, that the metal in 
 the gun shall be under a certain amount of initial strain, the exterior 
 being under a force of extension while the interior is under one of 
 compression. 
 
 18. Q. Is this condition arrived at under your method of cooling from 
 the interior? 
 
 A. Yes. 
 
 19. Q. Do you mean to have the tension uniform throughout the wall 
 of the gun? 
 
 A. No, not while the gun is free from the strain due to powder. When 
 subject to that strain, if the initial strain be of proper tension, it would 
 bring the whole of the thickness of the walls of the gun to the breaking 
 strain at the same instant, and would give us the benefit of the entire 
 thickness of the walls of the gun in resisting the force of the powder ; 
 while any solid-cast gun, cooled entirely from the exterior, is under an 
 initial strain the reverse of that just described, the exterior being under 
 a force of compression while the interior in under one of extension, and 
 the action of the powder joins with the exterior of the gun to break the 
 interior before the exterior is brought into useful action at all. 
 
 20. Q. Do you think a 12-inch rifle gun could be made and cast of the 
 same dimensions and weight as a 12-inch Kodmaii rifle, which could 
 endure 1,000 rounds, by cooling it so slowly as to have the metal in a 
 state of initial rest, or without strain ? 
 
 A. I should think it doubtful whether it would. That state of things 
 would be better than that obtained by casting and cooling from the exterior. 
 
 21. Q. Do you think the principle of initial tension necessary to be 
 embodied in a gun, in order to have the metal perform its full share of 
 work in restraining the action of a force from within outwards, having 
 a tendency to burst the gun or injure the bore? 
 
 A. I do consider it absolutely necessary. 
 
 22. Q. Does a gun which is cast solid, and cooled from the exterior, 
 have the same fineness of grain and texture at the surface of the bore 
 as a gun cast hollow ? 
 
 A. It does not. 
 
 23. Q. Is there any difference in texture between the iron in the cen- 
 ter of the block for a solid- cast gun and the exterior? 
 
 A. Yes, very considerable; that difference increasing with the size of 
 the block. 
 
 24. Q. Are there any cavities found in the center of most of the large 
 size blocks f 
 
 A. Yes; there are what they term draws. I would also remark that 
 the more rapidly the gun is cooled from the exterior the more likely are 
 these draws to appear. 
 
 Kep. No. 266 5 
 
66 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 25. Q. At what part of the casting would they appear, providing the 
 gun is cast to the shape at which it is afterwards to be finished ? 
 
 A. It would most likely appear near the trunnion, just above where 
 the most rapid taper takes place, the gun being vertical with the muzzle 
 up. 
 
 26. Q. Have any cavities ever been found in the hollow-cast gun 
 between the exterior surface and the surface of the bore T 
 
 A. Yes ; we found small cavities then. One of the guns, cast at Pitts- 
 burg, was found to have small cavities of that kind. 
 
 27. Q. Are there any differences of texture between the metal nearer the 
 cooling surface, exteriorly and interiorly, and the middle metal of the 
 wall of the hollow-cast gun I 
 
 A. There is some difference which may be detected by the practiced 
 eye ; the interior is finest-grained, and the exterior is next the middle 
 is generally the coarsest, though not always so. 
 
 28. Q. Would such a cavity, or difference in texture, indicate that 
 there were opposing tensions in the wall of the hollow-cast gun, and that 
 those tensions, which resulted from the abstraction of heat from the 
 exterior, were acting to assist the force of the charge to burst the gun ? 
 
 A. I do not think that these textures would indicate strain at all $ they 
 result from the difference in length of time the metal has in cooling. 
 
 29. Q. If the difference in time of cooling is not all that you depend 
 upon to produce the initial tension which you desire to obtain, what is ? 
 
 A. The initial strain is due to the difference in time of cooling, and 
 is produced by retarding the cooling of the exterior, so as to keep it at 
 a higher temperature during the process of cooling than that of the 
 interior of the gun. 
 
 30. Q. Is the point in the wall of your gun which cools last, the weak- 
 est ? 
 
 A. It ought to be the weakest. In the cooling of the gun the heat on the 
 exterior is not sufficient to prevent the congelation of the metal it 
 simply retards the cooling of the iron of the exterior after the metal has 
 solidified and to retain it in that condition while the interior is cooling, 
 so that the exterior, as it afterward cools, shrinks upon the interior, 
 a tire upon a wheel. 
 
 31. Q. Do you prevent entirely the cooling of the exterior, or is that 
 also a cooling surface ? 
 
 A. It becomes a cooling surface toward the latter part of the cooling 
 process. It is a cooling surface to the extent permitted by the exterior 
 artificial heat. 
 
 32. Q. Then the portion of the gun which cools last is not the exte- 
 rior, that being at some point between that and the interior? 
 
 A. Yes ; that is the case. 
 
 33. Q. Is it in that locality that you have the difference of texture or 
 the cavities that you speak of? 
 
 A. Yes ; where they occur. They are generally nearer the exterior 
 than the interior ; but they seldom occur. 
 
 24. Q. Have you ever noticed any facts which showed that the tension 
 in solid-cast guns, from the bore outwards, assisted the force of the pow- 
 der to enlarge the bore or burst the gun f 
 
 A. I have noticed cavities (slits like these draws) in guns, and my re- 
 collection is, that one gun, having such cavity or slit, was fired at Alger's 
 foundry, about or previous to the time Colonel Bornford cast his 12-mch 
 gun and showed a very small endurance. 
 
 25. Q. Were such tensions irremedial in all large columbiads previ- 
 ous to adopting that hollow mode of casting ? 
 
EXPERIMENTS ON HEAVY ORDNANCE. 67 
 
 A. My impression is that they were to a greater or less extent, and 
 my system of cooling was intended to correct this defect. 
 
 26. Q. We understand, then, that the principle object of the hollow 
 mode of casting is to have the tension reversed, thereby thus to assist 
 the tensile strength of the iron to restrain the force acting against the 
 bore of the gun to enlarge or burst it ? 
 
 A. The object is, as before stated, to throw the metal in a hollow-cast 
 gun upon an initial strain, the exterior being under a force of extension 
 and the interior Milder 'one of compression, and such, that under the law 
 of diminution of strain from the bore outward, the entire thickness of 
 the walls of the gun should, under the action of the central force, be 
 brought to the breaking strain at the same instant. 
 
 27. Q. What is the effect of time upon the tension of the solid-cast 
 gun, or, in other words, would a solid-cast gun be better when new ? 
 
 A. I do not think that that point is known ; 1 do not know. 
 
 28. Q. Theoretically what would be your opinion ? 
 
 A. I was going to state that I do not know whether a piece of metal 
 brought under a given extension by a tensile force and held there until 
 it should accommodate itself to that extended length, would be weaker 
 than if it had been left at its original position ; my belief is that it 
 would. 
 
 29. Q. Would you cool a hollow-cast gun at any different rate, if it 
 was to be fired to extremity when new, from that rate necessary to its 
 having sufficient tension remaining at the end of six years to endure the 
 same amount of firing?* 
 
 A. I think I should cool a gun intended to be used immediately more 
 rapidly than I would one not to be used in eight or ten years. This is a 
 point in which experiments are now in progress. I have examined the 
 tension in two pieces of metal taken from the same gun, at intervals 
 varying from six months to two years after taking it up, and no appreci- 
 able difference has yet been discovered. 
 
 30. Q. Do you think a hollow cast gun improved or deteriorated with 
 age? 
 
 A. My impression is that a hollow-cast gun must deteriorate after a 
 long time ; I do not know how long before the tension relaxes. I think 
 it must relax until it reaches the tension due to permanent elasticity. 
 
 31. Q. And if it be exactly right to bring the whole thickness of the 
 gun to the breaking strain at the same time, this cannot be the case 
 after the initial strain shall have been diminished ? 
 
 A. No. I do not know the law of diminution of strain by time in cast 
 iron; but we do know that within and even considerably above its limit 
 of permanent elasticity it is a very elastic substance, or one having great 
 longevity of strain. 
 
 32. Q. If a bar of cast-iron should be bent nearly to the breaking point 
 and kept there for any length of time, would it recover its original form? 
 
 A. That would depend upon whether it had been carried beyond the 
 limits of permanent elasticity. If the bar was strained to near its break- 
 ing point it would not return. 
 
 33. Q. If a bar should be held in its position for a number of years, 
 would it recover as completely its form as if the strain were immediately 
 removed ? 
 
 A. It would not. 
 
 34. Q. On page 28, first paragraph, Kodman's book, you say: "These 
 results appear to leave no doubt as to the superiority of the hollow over 
 the solid-cast guns while new. What effect time may have upon them 
 can only be ascertained by experience ; but it is difficult to understand 
 
68 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 how time could ever so far change their relative endurance as to cause 
 the solid-cast guns to surpass those cast hollow in this quality." We 
 understand that the first 12-inch rifle Rodman gun was made about six 
 years before it was completely tested when it burst. Did you cause a 
 solid-cast gun to 'be made at the same time, of the same model, of the 
 same material, and give it the same age for the relaxation of its tension 
 you gave the Fort Monroe 12-inch rifle, so that the question of time upon 
 the endurence of guns could be exactly determined"? 
 
 A. No; there was no cast-iron guns made at the same time that that 
 one was. 
 
 35. Q. Has the question of time upon the endurance of both solid and 
 hollow-cast guns been as yet satisfactorily determined f 
 
 A. It has not. 
 
 36. Q. Do you know of any example of a smooth-bore gun which has 
 exhibited a superior endurance, which endurance was attributed to the 
 length of time which elapses between the time the gun was cast and the 
 date of its being proved ? 
 
 A. I do not think of any instance of that kind now. 
 
 37. Q. Did you ever have a gun cast hollow, made of the same material, 
 with the same tensile strength, density, model, and calibre as the gun 
 cast in 1846 and proved in 1852, mentioned on page 217, Wade's book, 
 and w^hich endured 2,552 rounds, (while one made and proved in 1851, 
 which was about one-sixth stronger, burst at 72 rounds,) for comparison, 
 by subjecting it to proof after the same time had elapsed, for the purpose 
 of getting absolute knowledge on the point mentioned in the sixth para- 
 graph, on page 55, Rodman's book, in which you say you do not knoAv 
 whether a gun is better when new or after it has lain unused for a given 
 length of time ? 
 
 A. I do not think there was. I have no recollection of any experi- 
 ment of that kind. 
 
 38. Q. What time elapsed between the casting and proving of the 
 gnu known as the 12-inch Atwater rifle ? 
 
 A. I cannot tell you. 
 
 39. Q. Do you think that the Atwater system of rifling had a tendency 
 to increase or diminish the strain upon the gun I 
 
 A. I do not see that it should have the effect to increase it. My 
 impression is that there were three 12-inch rifles cast at the Fort Pitt 
 foundry, and I think by an order from the Navy Department; one was 
 to be rifled on the Atwater principle, one rifled on the plan which the 
 navy was to furnish, and the other on a plan furnished by me. My 
 recollection also is, that these guns were cast on a core-barrel that was 
 too short, and in finishing them with the proper length of bore they 
 bored through the interior hard metal around the core, thus taking away 
 the metal that was intended to be hard and strong to resist the action of 
 the powder on the bottom of the bore. I believe that all of these guns 
 began to break at the bottom of the bore ; I saw one, I know, that was 
 cracked at that point. 
 
 40. Q. Were they cooled from the exterior ! 
 
 A. I do not know in what manner they were cooled ; I understood 
 that they had cooled some guns by dropping water into the bore and 
 letting it evaporate. That was not carrying out my system. Whether 
 these guns were made in that way or not I do not know. 
 
 41. Q. Do you thiuk the fault in casting, to which you have referred, 
 satisfactorily accounts for the difference of endurance between the 
 Atwater rifle and the first rifle gun of the same calibre proved at Fort 
 Monroe. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 69 
 
 A. It is believed that the casting of the bore too short will partly 
 account for it ; the metal may not have been as good, and I believe these 
 guns were fired with quicker powder than that used in the Fort Monroe 
 army 12-pounder guns. 
 
 42. Q. Have no guns of large calibre, cast hollow and cooled from the 
 interior, burst at the foundry I 
 
 A. Yes ; there have been three or four that cracked either in the pit 
 or in the lathe. 
 
 43. Q. How do you account for that phenomena? 
 
 A. On the principle that they cooled them too rapidly from the interior, 
 and kept up the fire in the pit too long and kept it too hot. I was glad 
 to learn that guns could be thus cracked, for I had not, till then, sup- 
 posed it practicable to cool a gun so rapidly from the interior as to cause 
 it to break from the exterior. There was one, I think, cracked on the 
 lathe just as they commenced to turn it. These cracked guns show that 
 my system of cooling covers the entire field of initial strain. 
 
 44. Q. Have you noticed any small ruptures or cracks on the outside 
 of a gun previous to firing, cast upon your system ? 
 
 A. I have noticed such cracks in one or two cases around the opening 
 in the sinking head through which the water passes out after having cir- 
 culated through the cavity left by the core-barrel. 
 
 45. Q. Have you ever noticed any ruptures or cracks on the outside of 
 such guns less in extent than the complete bursting of the guns, during 
 proof or after firing in service ? 
 
 A. No ; I never have. I do not believe that we have received a gun 
 that will begin to break on the outside first, in firing. I may say here, 
 too, that in the manufacture of these guns a ring is taken off the sink- 
 head contiguous to the muzzle, which ring is planed through in a radial 
 direction until the initial strain breaks the part that is left unplaned ; 
 from the amount that this ring opens on the exterior we deduce the 
 extension per inch in length of the metal there. Then knowing the 
 extension which the metal of the gun will safely endure, we can tell 
 before the gun is finished whether or not it is over-strained, and no over- 
 strained gun has been accepted. 
 
 46. Q. Which is the most difficult gun to make to withstand the pres- 
 sure of the powder, a 10-inch or a 20-inch gun ? 
 
 A. I do not think there is any difference. 
 
 47. Q. Do you think you could determine how best to make a 40-inch 
 gun upon the basis of your experiments with the 20-inch gun ? 
 
 A. I do not suppose that it would be possible to determine with cer- 
 tainty, from the fabrication of the 20-inch g\m, the rate of cooling and 
 degree of decarbonization of metal necessary to make the best 40-inch 
 gun at the first trial that could be made by any number of additional 
 experiments. 
 
 48. Q. Would the force acting to rupture a large gun, with a proper 
 charge of powder, be more likely to rupture it than a small gun ? 
 
 A. The larger the gun, other thmgs being equal, the greater the strain 
 or pressure upon the square inch on the surface of the bore. This results 
 from the greater column of metal in front of each square inch of surface 
 pressed by the gas in the large than in the small gun ; but, by making 
 the powder for the 20-inch gun appropriate to that gun, it would have 
 no greater maximum pressure on the bore than the 10-inch with its appro- 
 priate charge and powder. I have no doubt of being able to impress 
 the same velocity upon a 40-inch shot that you do ordinarily upon a 10- 
 inch shot, and with little, if any more, tendency to break the large than 
 the small guns ? 
 
70 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 49. Q. Is the initial velocity of the 15-inch gun nearly uniform for like 
 charges and elevations ? 
 
 A. It is. 
 
 50. Q. And the same for other calibres? 
 A. Yes. 
 
 51. Q. Is that an indication that the force of powder is nearly uni- 
 form! 
 
 A. Yes. 
 
 52. Q. Is the quantity of gas resulting from the combustion of a given 
 quantity, by bulk, weight, and size of grain, uniform or nearly so ? 
 
 A. Equal weights of gunpowder, being equally well incorporated, 
 ought to evolve equal volumes of gas, irrespective of the size of grain. 
 
 53. Q. How many rifle 12 inch guns have been made upon your sys- 
 tem? 
 
 A. For the army there have been three made all experimental. 
 
 54. Q. How many in the navy? 
 
 A. I think three, also experimental. 
 
 55. Q. Will you give a brief history of the endurance of these guns ? 
 A. The first 12-inch gun, the only one that has been proved to extremity, 
 
 has been fired, I think, about 480 fires ; the records will show the exact 
 number. That gun burst, as was supposed, by the jamming and wedg- 
 ing of the projectile in the bore; the other two guns, one made by the 
 Knap Fort Pitt Foundry Company, and one at Alger's foundry, have not 
 been fired to exceed four or five rounds each; the one at Fort Delaware 
 only two rounds that I know of. The gun at Fort Delaware was made 
 by C. Alger, and the one at Old Point by the Knap Fort Pitt Foundry 
 Company. 
 
 56. Q. What is the present condition of these guns? 
 
 A. Their present condition cannot possibly be known accurately; the 
 one at Old Point, from the breaking of the projectile in it, has, I think, 
 two lands slightly depressed for a length of, say four inches, at a dis- 
 tance from the muzzle of about four feet. These guns have both been 
 measured by the star gauge, and the enlargement ascertained to be not 
 greater than we have frequently obtained in the proving of the solid-cast 
 smooth-bore guns, I think, from .012 to .017 of an inch. These guns 
 have both been subjected to extraordinary pressures from the jamming 
 and upsetting or breaking of the projectile inside of them. 
 
 57. Do ordnance officers all agree that the breaking or bursting of the 
 projectile is the chief cause ? 
 
 A. No; not that it is the chief cause, for the reason that it ought not 
 to occur ; but that it is a potent cause when it does occur, especially 
 the upsetting of the body of rifle projectiles. 
 
 58. Q. Can you give any account of the 12-inch rifles made for the 
 navy? 
 
 A. I cannot. I know that they did not endure satisfactorily. 
 
 59. Q. Do you regard either of the 12-inch guns in the army as safe to 
 be fired now with the ordinary charge I 
 
 A. I think they are both so. 
 
 60. Q. Could you predict with any certainty their endurance ? 
 
 A. I could not; for the reason that I do not know what effect may 
 have been produced upon them by the extraordinary pressures to which 
 they have been subjected. 
 
 61. Q. In many reports of the bursting of guns it is said that the rup- 
 ture was supposed to have occurred from the breaking or jamming of 
 shells in the bore. Why is it there is no certainty of the cause? 
 
 A. When a gun bursts, and you find the shot fired at that time to in- 
 
EXPERIMENTS ON HEAVY ORDNANCE. 71 
 
 dicate jamming or wedging, or you see that it is broken, the presumption 
 is, and I think as a rule a fair one, that that was the cause of the burst- 
 ing of the gun at that round. 
 
 JANUARY 26, 1869. 
 
 Brevet Brigadier General T. J. EODMAN recalled. 
 By the CHAIRMAN: 
 
 Q. In developing ordnance power it has been determined in your mind 
 whether it had better be by smooth or rifle bores, if the work to be per- 
 formed is the penetration of iron plates'? 
 
 A. My impression is that you can penetrate further with a rifle projec- 
 tile than with a smooth-bore. But at moderate distances the racking 
 effect upon the embrasure of a fort or the side of a ship or turret will be 
 greater from the smooth-bore of the calibres now known to be practicable 
 than with the rifle. I would also add that the smooth-bore is much less 
 liable to extraordinary or dangerous pressures than the rifle. It is gen- 
 erally agreed by ordnance officers of this, and I believe other countries, 
 that racking is more destructive of the plating of vessels than penetra- 
 tion ; I understand and believe it to be so. 
 
 Q. Have you determined in your mind whether it is better to load at 
 the breech or at the muzzle for guns of large calibre ? 
 
 A. 1 have not definitely determined that question. My belief is that 
 you can make a muzzle-loading gun stronger, that is, to resist a heavier 
 charge, than a breech-loader. The breech-loader would have the advan- 
 tage in embrasure, where it might close the port-hole with the muzzle ; 
 while loading at the breech thus prevents the ingress of small projectiles 
 during that time. 
 
 Q. Is a breech-loading gun stronger or weaker than a muzzle-loader, 
 leaving out of consideration the strength or weakness of the parts which 
 constitute the breech -loading attachment ? 
 
 A. All the breech-loading guns that I have seen are weaker necessarily 
 than the muzzle-loaders, for the reason that the breech-loader is deprived 
 of a great part of the stave or transverse resistance of which the muzzle- 
 loader, has the benefit. I would say that this might be to some extent 
 remedied by throwing the seat of the charge forward in the gun. 
 
 Q. Do you think that the central metal at the rear of the bore, reach- 
 ing through the cascable, adds to or diminishes the strength of the bar- 
 rel of the gun ? 
 
 A. It adds to the strength of the gun. 
 
 Q. How in a breech-loader having a breech-pin ? 
 
 A. It is not as strong as a solid breech. 
 
 Q. Have you ever seen an example of a cast-iron, unbanded gun, which 
 had ruptured longitudinally through the reinforce, in which the line of 
 fracture was not continued through the breech or cascable ? 
 
 A. I have seen examples where it was not continued through the cas- 
 cable; the fracture will always pass through the breech, more or less ob- 
 liquely, to a plane containing the axis of the bore. Where the breech 
 has the proper thickness of metal in the rear of the bore the fracture is 
 more likely to break off obliquely to the plane of the axis. 
 
 Q. Is the direction of fracture, shown in the various diagrams to be 
 found in the books usually entitled "Rodman's" and "Wade's" books, 
 
72 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 the general direction of such fractures if the guns are made of cast-iron 
 and unhanded I 
 
 A. They are for the model of the gun there shown. These guns dif- 
 fer in the breech from my present model. 
 
 Q. Is there any law in relation to the strength of hollow cylinders r 
 closed at each end, subject to a force from within, by which the differ- 
 ence in tendency to burst longitudinally or transversely can be deter- 
 mined ? 
 
 A. I do not know that such a law has been determined ; but, practi- 
 cally, that point can be determined, and a result will be found in my 
 printed report of experiments. I would state, too, that when the distance 
 or length of bore acted upon by the internal force is such that the tan- 
 gential expansion of the metal at the point of rupture will not admit of 
 the bending of the stave to an extent required to rupture it transversely 
 longitudinal, fracture will take place. If that distance be so short that 
 the length of stave acted upon will break transversely before extending 
 the metal to its breaking point tangentially, then transverse rupture will 
 first take place. 
 
 Q. Do you think that this explanation fully accounts for the trans- 
 verse ruptures which have sometimes occurred in guns of large calibre I 
 
 A. I do not know that it does fully. We have transverse ruptures which 
 occur from longitudinal rupture having first taken place ; for instance, 
 rupture at the breech may extend forward until one piece or the other 
 shall break off with a transverse fracture at its front end. 
 
 Q. If it be the pressure of the powder against the surface of the bore 
 that is the cause of the bursting of guns, how can you account for the 
 breaking through the breech to the rear of the continuation of the bore? 
 
 A. From the breech being too thin, or from the metal being very soft, 
 thus allowing the bottom of the bore to be pressed back until interior 
 annular rupture takes place. This subject is illustrated by my experi- 
 ments on small cylinders to be found in my printed reports, plate 7 and 
 page 153. . 
 
 Q. In treating of the transverse strain, on page 47 of your work, have 
 you not shown a form of fracture which never occurs to a gun burst 
 under fire? 
 
 A. I cannot say whether I have or not. That plate is intended to illus- 
 trate the form of the fracture that ought to occur when transverse frac- 
 ture of a gun occurs before longitudinal fracture. 
 
 Q. Is not the kind of fracture you have shown by diagram on that 
 page the kind which would result from the action of all the different 
 kinds of strain to which you have alluded, viz : " the tangential strain," 
 the longitudinal strain, and the strain of compression exerted from the 
 axis outward I 
 
 A. Yes ; when the surface pressed was so short as to cause transverse 
 rupture to first occur. I would also state that this diagram is an almost 
 accurate representation of fractures that occurred in small cylinders, 
 where transverse fracture first occurred, as on plates 4 and 5 of my 
 reports. 
 
 Q. Yet that is not the usual kind of fracture to be seen in guns which 
 are burst in firing I 
 
 A. I do not know that I have ever seen one of exactly this form j for 
 the reason, I think, that the length of bore pressed at the instant when 
 rupture begins, is generally greater than that which would first produce 
 transverse rupture. 
 
 Q. Then you think that the rupture does not occur until the projectile 
 has made a start towards the muzzle ? 
 
EXPERIMENTS ON HEAVY ORDNANCE. 73 
 
 A. No the projectile will always have made some progress towards 
 the muzzle before the breaking strain is reached. 
 
 Q. Are not the principal pieces forming the reinforce into which a 
 large gun is usually broken when it is burst in firing most frequently thrown 
 to the rear? Would not that indicate that the rupture began forward of 
 the trunnions and split the gun backwards through the breach I 
 
 A. They are ; for the reason that the gun has commenced to recoil, 
 and the motion of recoil, combined with their lateral motion, forces the 
 pieces obliquely to the rear. 
 
 Q. Would not that indicate that the rupture began forward of the 
 trunnions to split the gun backwards through the breech ? 
 
 A. No. 
 
 Q. Is not the pressure of the powder reduced by being expanded into 
 the increased space it would have when the shot had moved forward in 
 front of the trunnions ; can there be force enough left to start the rup- 
 ture at that point first, when it is remembered that the time of the action 
 of the force against that part of the bore is so much less than the time 
 of action in the chamber ? 
 
 A. The pressure of the gas, after it has attained its maximum pressure, 
 diminishes as the shot moves forward, and rupture ought not to take 
 place forward of the trunnions in a properly modelled gun. 
 
 Q. Does it take place in a model of your own u ? 
 
 A. I do not think it does, unless from the breaking or jamming of a 
 shot or shell in the chase of the gun. I have not seen one broken that 
 indicated that it had, without this cause. 
 
 Q. Can you tell at what point the gun would commence to rupture, if 
 you knew at what point in the bore the projectile jammed'? 
 
 A. It ought to commence at the thinnest part of the gun, behind the 
 projectile, or at its then position. 
 
 Q. Are not the fractures of the hollow cylinders, shown by shaded 
 drawings following page 144 of your book, principally like the theo- 
 retical fracture shown on page 47 ? 
 
 A. Some of them are and some are not. 
 
 Q. Is it not noticeable that but few of the fractures of these cylinders 
 are through the breech part, as we see them in most the large guns 
 which have burst in firing ? 
 
 A. Yes ; and for the reason that the thickness of metal in the breech 
 of the cylinder was proportionally greater than that in the gun. 
 
 Q. Do you think a 10-inch gun-block, cast solid and bored, as if for a 
 gun, and before it was turned on the outside, subjected to water pres- 
 sure, could be burst in> such a manner as to have the fracture through 
 the breech the same as the fracture usual in the gun burst by firing ? 
 
 A. I think it might. 
 
 Q. Would the longitudinal tension in a similar block, cast hollow, 
 have the tendency to direct the fracture through the breech, or other- 
 wise? 
 
 A. I think it would have a tendency to extend the fracture through 
 the breech, which would increase the strength of the gun. 
 
 Q. Opposite page 13 of your work there is a diagram of a 10-inch col- 
 umbiad, number 332, cast solid,* looking at the diagram, would you 
 think the fracture began forward of the trunnions or at the breech end ? 
 
 A. At the breech, unquestionably. 
 
 Q. On page 14 you say (referring to the gun last mentioned, and to 
 the hollow cast 10-inch gun, No. 331, which burst also) that it is quite evi- 
 dent that the fracture began at the breech in both cases ; yet the large 
 piece of the reinforce from the hollow-cast gun was thrown to a great 
 
74 EXPEEIMENTS ON HEAVY ORDNANCE. 
 
 height, and to the rear. Would not that indicate that the rupture 
 began first at the front ? 
 
 A. No $ for the reason, as I said before, this rear motion conies from 
 recoil. 
 
 Q. Is that sufficient to project the exploded part to the rear in the 
 manner described ? 
 
 A. Yes ; I think so. 
 
 Q. On page 14 you say (referring to the splitting of guns through the 
 breech) this has been the case with every columbiad you have ever seen 
 broken and indicates the breech as the weak point. Has any greater 
 strength been added to guns which have been made since 5 and if so, has 
 the fracture been different in such guns I 
 
 A. A greater strength has been added to the breech in my model of 
 gun. I cannot say whether the nature of the fracture has been changed 
 or not. 
 
 Q. If you should find the character of the fracture to be the same, do 
 you think you could remedy it by adding still greater strength to the 
 breech ? 
 
 A. I have no doubt of it. 
 
 Q. Are you aware that the first 15-inch hollow-cast guns made for 
 the navy were about three feet shorter than the army 15-inch gun to 
 accommodate them to the diameter of the turrets ? 
 
 A. I know that they were considerably shorter ; but exactly how much 
 I do not know. They were also thinner at the muzzle. The wall or 
 metal was about three inches thick at the muzzle, while in my model a 
 15-inch gun which is longer is five inches thick at the muzzle. I do not 
 know what the model of the navy gun was as cast. 
 
 Q. What is the thickness of wall at the muzzle in the army 15-inch 
 gun? 
 
 A. The thickness of the finished gun is as before stated five inches, 
 the diameter of the cast gun at the muzzle is, I think, 38 inches. 
 
 Q. Have you been informed that three of the 15-inch guns of the eight 
 used against Fort Fisher burst at the muzzle ? 
 
 A. I have understood that some 15-inch guns did ; I do not know what 
 number. 
 
 Q. Would those guns be stronger if made still thicker than seven 
 inches ! 
 
 A. Yes ; they undoubtedly would be if under proper initial strain ; those 
 that burst were not seven inches thick, nor anything like it, being as 
 before stated only about three inches thick at the muzzle. 
 
 Q. Are you aware that the navy reduced the thickness of the muzzle 
 afterward to about three inches, and reported that the gun was not weak- 
 ened thereby ? 
 
 A. I do not remember that they reduced their guns after the burst- 
 ing of those at Fort Fisher ; I am aware that they did reduce them below 
 the thickness of the army gun in order to get them through their small 
 port-holes. 
 
 Q. What, in your opinion, has caused the bursting of navy 15-inch 
 guns, and some of the larger Parrott s, at the muzzle ? 
 
 A. The bursting of the navy 15-inch gun I have no doubt was due, 
 either to the want of metal about the muzzle, or to the bursting of shells 
 within the gun. In the Parrott gun the bursting may have been due to 
 the bursting of the projectile in them ; but I think the most potent cause 
 was the too rapidly increased twist in the chase of the Parrott gun. I 
 have examined the fracture in some, and found it to be very nearly of 
 the same character as fractures produced in hollow cylinders by torsional 
 strain. 
 
EXPERIMENTS ON HEAVY ORDNANCE. . 75 
 
 Q. If it should be demonstrated that guns with three-inch thickness 
 of wall at the muzzle had more endurance than those with seven-inch 
 thickness of wall, how would you account for it? 
 
 A. I should account for it on the supposition that there was an adverse 
 initial strain on the metal in the thicker gun, independently of any 
 action of the powder. 
 
 Q. Is not the strength of the wall of the muzzle to resist a rupturing 
 force from within improved by turning off the outside metal which exerts 
 an opposing tension, as referred to in one of the previous questions? 
 
 A. Not in the hollow-cast gun, nor in any gun under a proper initial 
 strain. 
 
 Q. Would a shell exploding prematurely in the muzzle of a gun cause 
 a deep indentation, which would remain as evidence of the force if it 
 should burst the gun? 
 
 A. The chances are that it would. 
 
 Q. Have you ever noticed any such indentation in the surface of the 
 bore at the place of rupture, which would enable you to determine that 
 such a force had acted to burst the gun ? 
 
 A. I have not examined any of the 15-inch guns broken at Fort Fisher. 
 
 Q. If the. projectile did not make any indentation, crack, or enlarge- 
 ment, which could be seen after a premature explosion, could the gun be 
 injured to an extent which would cause it to give way afterwards with a 
 shell which did not burst, and have the subsequent rupture reasonably 
 attributed to the previous premature explosion? 
 
 A. That might or might not be with a rifle projectile. I can under- 
 stand that it might wedge so tight as to produce a strain; such as to so- 
 far weaken the gun that it might break at a subsequent fire and not 
 visibly mark the bore. It is a matter of record that in proving solid- 
 cast guns they have stood the proof of double charges and double shot, 
 and burst at the first service charge after. 
 
 Q. Have there been any experiments that have ascertained positively 
 whether the premature explosion of shells in the bore of a gun will 
 rupture it? 
 
 A. 1 do not know of any. 
 
 Q. What is your opinion ? 
 
 A. My opinion is that the explosion of the shell in the bore of a gun 
 subjects the gun to an undue strain, which may or may not be sufficient 
 to burst it. 
 
 Q. What is the meaning the term work, referred to in modern essays 
 on artillery, in relation to projectiles, and what is the footpound or foot 
 ton referred to in that connection ? 
 
 A. The foot pound is one pound avoirdupois, raised one foot vertical 
 lift. 
 
 Q. Is there not an equivalent of heat for foot pounds or tons, and a 
 mechanical equivalent of foot pounds for a unit of heat, called Joule's 
 equivalent? 
 
 A. Undoubtedly so. The present theory is that heat and work, or 
 living force, are convertible one into the other, or that heat is due to 
 molecular motion. 
 
 Q. What is the mechanical equivalent for a unit of heat? 
 
 A. I do not, with certainty, remember that now. I believe it is stated 
 to be that amount of heat or fire effort necessary to raise one pound of 
 water one degree in temperature, and that its equivalent in work is equal 
 to raising 774 pounds one foot high; I am not positive as to the figures. 
 
 Q. Would it not be possible to determine the amount of tension in a 
 hollow-cast 15-inch gun, upon the basis of the units of heat, proportioned 
 
76 - EXPERIMENTS ON HEAVY ORDNANCE. 
 
 to the whole number in the melted iron, communicated to the water 
 flowing through it, and upon the equivalent in foot pounds for that 
 heat? 
 
 A. I do not now see how you could do it. If you knew just how much 
 of that heat was taken off from the surface of the bore, and how much 
 from the exterior, and the times at which they were taken off, I suppose 
 an approximation to the strain or tension upon the metal could be made ; 
 but I should greatly prefer to rely upon the results obtained from the 
 ring taken from the muzzle of the gun to a calculation made on this 
 basis. 
 
 Q. If a sufficient number of shots were fired from the 15-inch gun 
 with a sufficient rapidity, and each of them upset or fitted so tightly in 
 the bore as by friction of rubbing against its surface to retard its motion 
 to the extent which would just permit each shot to move .to the muzzle 
 and stop, having expended all the force of the powder, sufficient heat 
 would result to melt the gun to the same state of fluidity from which it 
 was cooled when cast, would it not? 
 
 A. Undoubtedly sufficient heat would result from a sufficient number 
 of shots fired with a sufficient rapidity; but I know of no means of accom- 
 plishing that feat at this time. 
 
 Q. Might not the tensions in a hollow-cast gun be so increased by 
 friction, resolved into heat in this manner, as to burst it ? 
 
 A. Not with our present means of rapidity of firing, and a gun having 
 a proper initial strain. 
 
 Q. Is it not more probable that the friction which results in heat, 
 communicated so suddenly to the surface of the bore near the muzzle, 
 is the cause of the rupture of guns at that part, than that the bursting 
 of shells in the muzzle is the cause of the bursting of the gun f 
 
 A. I do not think so. 
 
 Q. Which would create the most friction against the surface of the 
 bore, a rifle projectile or a spherical projectile f 
 
 A. A rifle projectile. 
 
 Q. Do you think that the additional heat communicated by the fric- 
 tion of the projectile upon the bore of rifle guns acts to any great extent 
 as an additional force to aid the powder in rupturing the gun? 
 
 A. I do not. In a gun free from strain when fired, additional heat 
 communicated to the interior of the metal beyond that of the exterior 
 will increase its resistance ; for, generally, in guns where the initial strain 
 is too small, additional heat at the interior will increase its resistance ; 
 while in those where the initial strain is too great, excess of heat of the 
 interior over the exterior acts to diminish their resistance. 
 
 Q. Have you ever made any estimate of the number of degrees the 
 surface of the bore would require to be raised suddenly in temperature 
 in order to burst the hollow-cast gun I 
 
 A. No, I have not. I know this, though, that the expansibility, per 
 inch in length, of good gun metal (cast-iron) is about .003" of an inch, 
 while the expansion of cast-iron from 32 to 212 is put down in the 
 books at a little over .001" of an inch per inch in length. It would, 
 therefore, require a gun to have an initial strain which would produce 
 at least .002" of an inch extension per inch in length, onthe exterior 
 of the gun, in order that a difference of temperature between the 
 interior and exterior of 180 should at all endanger its safety. 
 
 Q. In speaking of the tensions which result from cooling a gun from 
 the interior, in answer to a previous question, you only referred to the 
 tangential strain. Would there -not also be a longitudinal contraction 
 of the outsifte after the freezing of the interior I 
 
 A. Certainly there would. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 77 
 
 Q. What would be the effect of inserting heated shot in the bore of a 
 gun so strained tangentially and longitudinally? 
 
 A. The tendency would be to unduly increase the initial strain of a 
 gun that was already under a proper initial strain before its insertion. 
 
 Q. Would the effect of this force generated by the heat be to enlarge 
 the bore of the gun ? 
 
 A. It would have the effect to enlarge the bore of the gun, and to 
 increase the initial strain if a proper one, and to diminish it if an 
 improper one, before its application. 
 
 Q. Whatever force tends to enlarge the bore of a gun is a force 
 having a tendency to rupture the gun, is it not ? 
 
 A. That depends entirely upon the condition of the gun as to initial 
 strain before the application of such force, and upon the nature of the 
 force. If the. force result from excess of heat on the interior of the gun, 
 it would be beneficial where the initial strain is much too small, and 
 hurtful where it is too great. If the force be purely a mechanical one, 
 its tendency will be in all cases to burst the gun. 
 
 Q. On page 47 of your book a diagram is shown dividing a cross- 
 section of a gun into voissoirs or staves, and you speak of the effect of 
 pressure as having a tendency to bend these staves outward in the mid- 
 dle of their length, as shown by the first diagram on the page. The 
 effect of cooling from the interior edge of the stave is to reverse that 
 curve and give each imaginary stave the strong tendency to burst the 
 other way, is it not ? 
 
 A. It would. The effect, however, is beneficial in a gun having a proper 
 or too small an initial strain, as it increases the length of the bore, along 
 which the transverse resistance acts beneficially. 
 
 Q. Then, if any heat should be added to the inner edge of the stave 
 afterwards, when the gun is in use, the tendency to still further bend it 
 would result, would it not? 
 
 A. It would. And to still further increase the length of bore that 
 would offer transverse resistance, unless the initial strain were already 
 too great. 
 
 Q. Will not this tendency to bending outward of the staves from after 
 heating the gun cast hollow, from the direct communication of the heat 
 of the powder, gas in motion, or the indirect heat which may result from 
 the friction of the shot, account for the breaking of the gun through the 
 breach ? 
 
 A. No; not unless the gun be previously under an unduly great initial 
 strain. 
 
 Q. Is there, ordinarily, much heat communicated to the surface of the 
 bore by contact with the hot gas of the powder? 
 
 A. There is considerable heat communicated; but the conducting 
 powers of the metal are such as to disseminate the heat communicated 
 to the bore through the mass of the metal, so as to render the difference 
 in temperature between the inner and outer surface of the bore so small 
 as not to be injurious with our present most rapid rate of firing upon a 
 gun, either free from strain or having a proper initial strain. 
 
 Q. Is the fact that there is not more heat communicated partly because 
 gasses are non-conductors of heat, and after the gas, which is in actual 
 contact, has given off its increment of heat, it becomes comparatively 
 cold and is then interposed as a non-conductor between the hotter gas 
 and the surface? 
 
 A. I think that may be so. 
 
 Q. Where a current of hot gas is passing rapidly over the surface, is 
 the condition changed to any degree! 
 
78 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 A. The condition would undoubtedly be changed, and more heat would 
 be communicated in a given time. 
 
 Q. Would net the surface of the vent receive more heat on this account 
 than any other equal surface in the bore of the gun? 
 A. Undoubtc dly it would. 
 
 Q. Do you tLink the heat which is communicated to the metal which 
 surrounds the vent has, by causing a cylinder of metal which has the 
 vent for its axis to expand unduly, any tendency to cause the line of 
 fracture when a gun bursts to intersect the vent ? 
 
 A. I have no doubt that it has a tendency that way, but it is not so 
 great as invariably to cause the fracture to pass through the vent. 
 
 Q. Do you not think that the increased amount of heat, which will be 
 communicated from the rapid passage of the hot gas past the windage, 
 over the top of the shot, has the tendency, by heating the top of the bore 
 over the shot more than any other part, a tendency to cause the plane of 
 fracture to take the direction usually observed to be perpendicular? 
 
 A. I don't know that it would. 
 
 Q. Within certain limits, and in a gun not having tension enough to 
 resist the pressure of the powder in the best manner, might it not have 
 increased strength to resist the pressure if it were heated from within 
 to the extent, for instance, that would just create the best degree of 
 tension ? 
 
 A. Yes ; a gun not having sufficient initial strain might be brought 
 to it by heating the interior. 
 
 Q. Do you think that guns cast solid would be stronger after having 
 become heated by successive fires to a certain extent ? 
 
 A. I do. My experience is, that in firing solid-cast guns to extremity 
 they are more likely to burst at the first fire in the morning than at any 
 other time ; and that they would have stood a greater number of rounds 
 if the firing had been continued while the gun was warm, I doubt not. 
 
 Q. Then it is not true that the gun that is so constructed as to embody 
 the degree of initial strain necessary to its restraining the elastic pres- 
 sure which the powder exerts in the most effective manner is put in the 
 worst state of tension as regards its ability to resist the force with which 
 its interior would enlarge as it is heated by the gas or the friction of the 
 powder or projectile upon its interior surface ? 
 
 A. If no margin had been allowed for the effects of the heat, on the 
 interior, in fixing the initial strain, the interior heat would act injuri- 
 ously. 
 
 Q. Then you think if the gun had too much or too little tension it 
 would be in a bad condition to resist the expansive forces of heat ? 
 
 A. If the gun had a too great initial strain, interior heat would act 
 injuriously ; if it had too little initial strain, it would act beneficially. 
 
 Q. How if it had no initial strain at all ? 
 
 A. It would act beneficially ; if the initial strain had been adverse it 
 would also be beneficial, and in a still higher degree. 
 
 Q. Was the firm-name or style Knapp & Wade at any time during 
 your experience with the Fort Pitt foundry ? 
 
 A. Either Knapp & Wade, or Knapp, Wade & Co., I am not positive 
 which, was the style of the foundry at one time. 
 
 Q. Do you know whether Major Wade was at any time a partner in 
 the Fort Pitt foundry while he was in service as an officer of the army 
 or a clerk in the Ordnance Office ? 
 
 A. I have no positive knowledge on the subject ; but my firm belief is 
 that he was never connected with the foundry as partner while in the 
 employ of the government in any capacity. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 79 
 
 Q. What was the date of the last patent issued to you or to Mr. Knapp 
 for the hollow mode of casting guns ? 
 
 A. I only had one patent. My recollection is that that was issued in 
 August, 1847, and renewed in August, 1861, for seven more years, and 
 that it expired in August last. 
 
 Q. Has any patent for the same thing, or for a similar invention, been 
 given to Mr. Knapp or any other parties ? 
 
 A. No, not to my knowledge. 
 
 Q. Have you applied for still further extension ? 
 
 A. No, I have not. 
 
 JANUARY 27, 1869. 
 Brevet Brigadier General T. J. EODMAN recalled. 
 
 By the CHAIRMAN : 
 
 Question. You informed us yesterday that work and heat are con- 
 vertible. Are we to understand you, from that statement, that as one is 
 expended the other is evolved, and vice versa ? 
 
 Answer. Yes ; or, in other words, the living force of work stored up 
 in a shot in motion, for example, will, on arresting or reducing the veloc- 
 ity of the shot, be converted into heat or molecular motion. The quan- 
 tity of heat developed and the work remaining in the shot at any instant 
 of time being together exactly equal to the quantity of work originally 
 in the shot. 
 
 Q. Will you state the average rate of extension, per inch, within rup- 
 turing, for gun iron ? 
 
 A. It will run from .0025" to about .0035" of an inch per inch in 
 length ; the best ought to extend (.0035") 3 thousandths of an inch per 
 inch in length, before breaking. 
 
 Q. Also the average rate of extension per inch within permanent elas- 
 ticity for gun iron '? 
 
 A. Good gun iron will run from 8 to 12 thousand pounds per square 
 inch, while its permanent elasticity will not be sensibly or very injuriously 
 impaired inside of 15,000 pounds. I find in this sample, tested here, 
 (referring to the book,) the absolute limit of permanent elasticity is 
 9,000 pounds per square inch; the specimen extended (.00043") Toinroo^ 
 of an inch, having a permanent set of (.00001") 1 ^ of an inch ; and 
 at 15,000 pounds the same specimen extended (.00080") T Q^O f ari 
 inch, and had a permanent set of (.00007") jo-oWo f an inch- 
 
 Q. What is the additional temperature, in degrees, which gives expan- 
 sion per inch equal to the extension to the limit of permanent elasticity ? 
 
 A. That would require some calculation. 
 
 Q. Could you approximate it ? 
 
 A. It would take about 80 to expand the metal to an extent equal to 
 the extension for good cast-iron at the limit of elasticity. 
 
 Q. What increase of temperature, in degrees, will give expansion per 
 inch equal to the average extension to the breaking point? 
 
 A. It would take about 600, supposing the expansion of the metal to 
 be uniform between the limits of 32 and that point. 
 
 Q. What was the difference of the rate of cooling employed when a 
 15-inch gun was cast which ruptured longitudinally in the pit, and the 
 one to which you have alluded, as showing that your mode of cooling- 
 did give the required initial strain i. e., what was the difference of 
 temperature between the exterior and the interior at the instant each 
 froze? 
 
80 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 A. I do not know what the exact condition of the temperature was. 
 My impression is that the metal was at the same temperature inside as 
 p.ut when it congealed; but I have no doubt that it congealed^rstf on the 
 inside. 
 
 Q. You have stated that you accelerate the time of cooling a hollow 
 gun to about half the time required to cool it entirely from the exterior. 
 What is the time usually required to cool a hollow cast 15-inch gun, and 
 is the time nearly uniform for that size of gun ? 
 
 A. It is almost uniform ; it is intended to be uniform, and generally 
 occupies about six days. 
 
 Q. What difference of temperature between the interior and the 
 exterior, while cooling, have you noticed as giving the best state of 
 strain in a gun cast hollow ! 
 
 A. We have not been able to determine the temperature of the gun 
 itself upon the exterior ; we have only ascertained the temperature of 
 the pit in which the gun-flasks were, and the change in temperature of 
 the ingoing and outcoming water. My recollection is that the tempera- 
 ture of the water is about 156 as it comes out just after casting ; it 
 would come up to that as the highest point while the water circulated 
 through the core-barrel. After the core-barrel is removed the water 
 circulates through the cavity left, by which the water is raised to a 
 temperature something less than 212, so that it does not make steam ; 
 this temperature gradually recedes. As the gun cools, the temperature 
 of the pit is generally from 500 to 600 during the first two days ; then 
 the pit gradually cools as the gun cools, the water circulating all the 
 while. 
 
 Q. Heretofore, in speaking of cast-iron, you have called it a good con- 
 ductor, saying that heat was quickly dispersed throughout the mass. 
 Is it a worse conductor while it is being cooled in the foundry pit ; if 
 not, how can there be so great a difference between the interior and 
 exterior while a gun is being cooled ? 
 
 A. In cooling a gun from the casting temperature we start with a 
 very high temperature, so that the difference in temperature between 
 the interior and exterior cooling surfaces is very great, that of the 
 interior being not above 200, while the exterior is at a red or even a 
 white heat ; and w T e know that the greater the difference in temperature 
 of the heat-receiving surfaces, the greater will be the difference in tem- 
 perature of the heat-imparting surfaces; or the more rapidly a body 
 receives or parts with heat the greater will be the difference in tein- 
 derature at the surface, and at a given distance, within the body, from 
 its surface. In practice, in firing heavy artillery, the heat is so slowly 
 applied that the difference in temperature of the exterior and interior 
 surfaces of the gun isnever great. 
 
 Q. General, here is a target record of the firing of the 12-inch Rod- 
 man rifle gun, which burst at Fort Monroe at the 472d round. Will you 
 please examine it and inform us if the record shows the cause of the 
 bursting of the gun I 
 
 A. The only thing that would indicate the cause of the bursting at 
 that round is the indication of the shot having jammed in the bore of 
 the gun, as shown by the impression of the lands of the gun upon the 
 surface of the shot. 
 
 Q. What is the character of fracture ! 
 
 A. The fracture is longitudinal, and deviated when it reached within 
 about four feet of the muzzle a little shorter on one side than the other. 
 
 Q. Would this fracture indicate that the breech was not thick enough ? 
 
 A. Yes ; that would indicate that the gun would be strengthened if 
 
EXPERIMENTS ON HEAVY ORDNANCE. 81 
 
 the thickness of the breech was increased; however, though the line of 
 fracture should run through the middle of the gun, leaving the two sides 
 almost equal, it would not necessarily indicate that the breech was too 
 weak. 
 
 Q. In what part of this gun do you think the rupture began? 
 A. My impression is that it began at the rear part of the gun ; it is 
 possible that it may have commenced at the fore part of it, though the 
 manner in which it broke indicated that the crack was running forward 
 at the point where transverse rupture first occurred. 
 Q. Was the distance any of the parts were thrown great ? 
 A. About 21 yards seems, from the report, to be the greatest distance 
 to which any of the pieces were thrown. 
 Q. What was the direction in which the parts were thrown ? 
 A. About 10 to the rear, I believe. I understand that two fell on the 
 right, about 10 to the rear, from a perpendicular line to the right, across 
 the line of fire. 
 
 Q. Is it probable that any of the parts were thrown upward to a great 
 height ? 
 
 A. I think not, from this fracture, (referring to a drawing shown.) 
 Q. Were there any cracks or flaws shown on the surface of the bore 
 previous to the rupture ? 
 
 A. It is said here, referring to report, that none were discovered. I 
 examined one-half of the gun myself after it was broken, and discovered 
 no indication of previous deterioration. 
 
 Q. Would this indicate that the gun had the proper degree of tension? 
 A. I cannot tell whether or not ; there was no ring taken from this gun. 
 It was the first gun of that calibre cast, and was cast before I began to 
 take rings for initial strain. 
 
 Q. Are not all the indications such as would show that the rupture 
 began on the top almost simultaneously for the whole length of the gun? 
 A. I do not know that they are ; the two pieces into which the gun 
 was broken being so nearly equal, the line of fracture might have run 
 forward. I think it is highly probable, however, that nearly the whole 
 length of the longitudinal fracture was made at the same time. If the 
 shot had jammed a little in rear of the first cross fracture, the pressure 
 of gas would have been acting upon the whole length of bore behind 
 that; and if the fracture had commenced at that point it could, and 
 most likely would, have produced just such a fracture as is shown. 
 
 Q. What pressure per square inch upon the surface of the shot, 
 indented as in the report, would be the least which could cause the in- 
 dentation or marks referred to in the report by Colonel Bagler ? 
 A. I could not tell you that. 
 
 Q. Do you know the limit of pressure upon the square inch of 
 surface for metals rubbing together at which lubrication ceases to be 
 advantageous ? 
 
 A. No, I do not. It would be different in different metals ; and it 
 ceases to be advantageous whenever the pressure is so great as to cause 
 the interlocking of the particles of the rubbing surfaces. 
 
 Q. If the pressure were greater than the limit referred to considerable 
 friction would result as the shot was sliding along the bore ? 
 A. Yes ; a great amount of friction would be the result. 
 Q. Might not this friction account for the reduced velocity of the shot? 
 You will notice round 405 had 40,000 pounds' pressure and 1,208 feet 
 velocity, while the last round, at which the gun burst, No. 472, with the 
 same pressure, gave only 990 feet velocity. 
 
 A. Yes ; to some extent. Suppose the shot had jammed at say to 
 Eep. No. 266 6 
 
82 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 of the distance from the bottom of the bore to the muzzle, and the 
 gun burst ; then the shot would leave with the velocity which it had at 
 that point. Whatever friction existed tended to diminish the velocity 
 of the shot. 
 
 Q. Might not this friction so heat the interior of the gun as to cause 
 increased tension tangentially sufficient to cause the rupture? 
 
 A. No, I think not 5 it has not time to act before the shot is gone. 
 
 Q. Would not the increased tension, by bending the staves outward 
 at the ends, have the tendency to cause the fracture through the breech ? 
 
 A. Yes ; though I think not to any appreciable extent. Where a con- 
 siderable length of bore is acted upon by the gas the whole stave is car- 
 ried out bodily, except at the extremities ; but only so far as the tan- 
 gential resistance or extension of the metal will permit them to go, the 
 stave resistance being of no appreciable value beyond, say, five calibres 
 in length. 
 
 Q. Has this gun the increased thickness through the breech you have 
 previously referred to in answer to a question, and which you believed 
 would have a tendency to prevent breaking through the breech ? 
 
 A. My recollection is that the gun had a thickness in the breech of 
 something over a calibre and a half, which experiment has shown, with 
 small cylinders, to be about as much thickness as was valuable, there 
 being very little increased resistance from greater thickness. 
 
 Q. Do you now, in view of the results of that experiment, propose to 
 still further strengthen the breech of the gun ? 
 
 A. No, I think not, unless we should find that guns break generally 
 in such a manner as to indicate that the breech is too thin. 
 
 Q. Will you examine the record of the 12-inch hollow-cast gun, called 
 the Atwater gun, which burst at Fort Monroe on the llth of January, 
 1866, and inform us if it did not break through the breech 1 
 
 A. The data here given is not sufficient to form a correct idea ; from 
 the report I should think it probably did. 
 
 Q. Did the 8-inch Eodman rifle which burst December 4, 1865, burst 
 through the breech ? 
 
 A. I do not know. This report does not state whether the gun broke 
 through the breech or not. 
 
 Q. What was the nature of the rupture of the 8-inch Kodman rifle 
 which burst on the 3d of January, at the 86th round ? 
 
 A. My recollection is that that gun burst at eighty-odd fires j that 
 gun was made for grooved projectiles exclusively. We found that in 
 firing with equal charges of powder and equal weights of projectile the 
 pressure-gauge indicated, almost invariably, a greater pressure behind 
 the grooved projectile than behind the expanding one. The initial 
 velocity of the grooved projectile was generally a little less than that of 
 the expanding projectile. I do not know the nature of the fracture. 
 
 Q. Will you examine this record relating to the 13-inch Eodman gun 
 which burst July 27, 1864, and state if the gun did not rupture through 
 the breech? 
 
 A. That gun broke through the breech, as shown in this report. I 
 have not examined the fragments of the gun. 
 
 Q. Was not this gun made after the latest improved model? 
 
 A. I believe it was. 
 
 Q. What was the thickness of the iron at the breech ? 
 
 A. I think it was about the same proportion as other guns of my 
 model j that is, about a calibre and a half thick. 
 
 Q. What was the tensile strength of the iron of which the gun was 
 made ? 
 
 A. 1 do not remember. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 83 
 
 Q. To what extent did the tensions due to the rate of cooling from 
 within add to the ability of this gun to restrain a pressure from within ? 
 
 A. I cannot tell you to what extent ; there was no ring taken from 
 that gun, either. 
 
 Q. Suppose this gun had been cast parallel with its largest diameter 
 and closed with a similar breech at both ends, what pressure per inch of 
 water should it have borne without breaking, on the supposition that all 
 the parts of the wall were brought to the breaking strain at the same 
 instant ? 
 
 A. If the pressure should act along the whole length of the gun, you 
 would have none but the tangential resistance to overcome ; and if the 
 entire thickness of the walls should be brought into play, or to their 
 breaking strain at the same instant, the interior pressure required to 
 burst it would be about 64,000 pounds to the square inch. 
 
 Q. Do you notice that shot No. 735 has the pressure recorded of 
 180,000 pounds per inch; is that the pressure recorded by the Rodman 
 instrument ? 
 
 A. I presume it is ; I do not know certainly. 
 
 Q. Is that instant pressure, or is it momentum I 
 
 A. It is mainly pressure ; there is a small amount of momentum, not 
 enough, as I believe, to materially affect the indications of pressure; it 
 may vary, in a pressure of that magnitude, as much as 5,000 pounds to 
 the square inch. It is not claimed for this instrument that it gives abso- 
 lutely and accurately the pressure of the gas in the gun, but it is claimed 
 that it is a valuable guide to artillerists and gives indications of pressure 
 sufficiently accurate for practical purposes. 
 
 Q. Do the indications of pressure given by the Eodman instrument 
 resemble the results got by Colonel Bomford's experiments in firing a 
 steel ball from a hole drilled in the side of the gun ? 
 
 A. No; that depends upon a different principle. Colonel Bomford 
 inferred the pressure of gas on the gun from the number of thin pieces 
 of pine which a pistol ball thrown by the gas of the gun would penetrate. 
 The ball in that barrel, placed behind the seat of the shot, and where the 
 maximum pressure is always found, was so light that it was thrown out 
 before the full pressure of gas in the gun had been developed, and thus 
 indicated a less pressure than actually existed. 
 
 Q. Do you think there is any difference in the pressure between that 
 which acts upon the bottom of the bore or the top ? 
 
 A. In the gun that has windage of considerable magnitude the pres- 
 sure on the top will be a little less than that on the bottom, but not 
 materially so. 
 
 Q. Is there equal pressure to the square inch against the rear of the 
 projectile and against the bottom of the bore or chamber? 
 
 A. No; there is a little more against the bottom of the bore, else the 
 gas would not move from it the gas would move towards that point 
 where the least pressure is found. 
 
 Q. As the shot moves forward towards the muzzle, is the pressure 
 reduced on account of the increased space into which the gases have 
 expanded ? 
 
 A. Undoubtedly it is. 
 
 Q. As the pressure is reduced against the rear of the shot, is it also 
 reduced as against the bottom of the bore or chamber f 
 
 -A. Certainly it is. 
 
 Q. Are the indications of the internal pressure instrument equal to the 
 indications of an external instrument and inserted in a hole drilled through 
 the side of the gun ? 
 
84 EXPERIMENTS ON HEAVY ORDNANCE. , 
 
 A. There has always been found, where the two were used together, a 
 slight difference, the outer one being a little greater. The difference is 
 supposed to result from the presence of the internal pressure gauge in 
 the powder, thus retarding the rate of inflammation of the charge ; the 
 momentum of the gas that strikes against the piston in either case is 
 very trifling. 
 
 Q. Have you ever had indications from the external instrument of 
 higher pressures at two calibres from the bottom than at the bottom 
 of the bore ? 
 
 A. There is no such case that I now remember. 
 
 Q. Most of the tables of pressures in your book are means for a num- 
 ber of rounds, are they? 
 
 A. Yes ; they are generally so. 
 
 Q. When the external instrument indicates the highest pressures, the 
 shot has begun to move and has left its original position, has it- not i 
 
 A. Yes ; it must have moved from its original position before the gas 
 has reached its maximum pressure. 
 
 Q. At that period of time, is the pressure against the piston of the 
 instrument against the rear of the shot and against the bottom of the 
 bore the same ? 
 
 A. They are nearly the same; there would be in theory a little greater 
 pressure against the bottom of the bore than against either the shot or 
 the instrument ; but not perceptible in practice. 
 
 Q. Suppose there was another instrument inserted at the bottom at 
 that instant; would it also indicate the same pressure as the other 
 instrument ? 
 
 A. Yes ; in practice it would. 
 
 Q. On page 176 of your book is a table of pressures at different points 
 along the bore; at bottom a mean of three fires with coarse powder 
 you have 10,000 pounds; at two calibres from bottom, 26,001 pounds, 
 pressure. Can you account for this incongruity, except upon the theory 
 that the hole in the side of the gun was obstructed by the grains of 
 powder at the bottom and not obstructed at two calibres! 
 
 A. That may possibly have been the case. I know of no other. 
 
 Q. How can you account for the other incongruity, that at 14 calibres 
 the pressure was greater than at 12? 
 
 A. In this way: these are indications that were made on disks of cop- 
 per. It is believed to be due to the vibration of the metal in the gun 
 after the shot has left striking the knife edge into the copper disk. If 
 placed in a thin walled gun, towards the muzzle, it would be found to 
 be almost invariably the case that one could see th emarks of the indent- 
 ing tool in the copper, showing that it had struck quite a number of 
 times, and that it had thus increased the (length of) cut in the copper 
 which indicates the pressure. 
 
 Q. Were all the holes drilled at right angles to the axis of the bore, 
 or was the hole at 14 calibres inclined forward ? 
 
 A. My recollection is that they were all right angles to the axis of 
 the bore. 
 
 Q. Have you ever noticed any indication of the instrument which 
 would lead to the conclusion that projectile force is what you measure 
 instead of pressure? 
 
 A. No, I have not. 
 
 Q. Is it not the pressure of the powder which ejects the shot from the 
 gun and gives it its velocity? 
 
 A. The pressure evolved from the powder does it. 
 
 Q. How is it that there is so little difference in velocity to the shot, 
 
EXPEEIMENTS ON HEAVY OKDNANCE. 85 
 
 while the pressures from the same powder, in the same gun, vary from 
 8,000 pounds pressure to 180,000 pounds? 
 
 A. The small differences of the pressure are, to my mind, most readily 
 explained on the supposition that the charge is not ignited at each dis- 
 charge in the same manner. A primer that only succeeded in igniting a 
 single grain or so at a single point, will not give such pressure as a 
 stronger primer that darts its volume of flame clear through the charge 
 of powder ; the origin of ignition being a point, in one instance, and a 
 cone running through the entire charge in the other. These extraordi- 
 nary differences that are found, I believe to be due to the irregular action 
 of the projectile, the wedging, or jamming, or breaking, of the shot in 
 the bore, for I do not see how the knife edge can be driven into the cop- 
 per without pressure, nor how pressure can exist in the bore of the gun 
 without forcing the knife edge into the copper. 
 
 Q. Was the model of the Kodman gun based upon the indications of 
 this instrument ? 
 
 A. My recollection is that it was so in part. 
 
 Q. Would the steel ball fired from Colonel Bomford's experimental gun 
 have had higher velocity at two calibres from the bottom if a musket 
 barrel had been inserted in the hole in the side of the gun to increase 
 its length, and the time of action of the pressure ? 
 
 A. Undoubtedly it would. 
 
 Q. On page 197 you have a table showing pressures at different points 
 along the bore in guns of three different calibres, 7-inch, 9-inch, and 
 11-inch, showing the velocity of the shot due to equal columns of powder, 
 behind equal columns of metal. If the pressures had been greater in 
 one of these guns under such circumstances the velocities would have 
 been greater, yet the < velocity is remarkably alike from the three guns 
 for a mean of ten fires, while the mean pressure is three times as great 
 in the 11-inch gun as in the 7-inch, and twice as great in the 9-inch as in 
 the 7-inch. How do you account for that ? 
 
 A. I do not know that I can account for it. The only explanation that 
 I can see applicable to it is that the powder is more rapidly inflamed in 
 a large than in a small calibre ; this would give increased maximum 
 pressure of gas without materially increasing the velocity of the shot. 
 
 Q. Has the length of the hole, from the axis outward, in which the 
 pressure instrument is inserted, which is greater in the 11-inch gun 
 because of the greater thickness of wall, nothing to do with it ? 
 
 A. I do not think it has, not to any appreciable extent. 
 
 Q. Have any smooth-bores of large calibre burst when fired with solid 
 shot ? 
 
 A. None except one 13-inch, by experiment, of my model. 
 
 Q. What is the cause of the bursting of the experimental gun made 
 upon your model, of which you speak? 
 
 A. It was worn out, having burst at the 738th fire ; the pressures of 
 the last five rounds, with 55 pounds of No. 5 powder, were 152,000 
 pounds, 170,000, 180,000, 200,000, and 160,000 pounds per square inch. 
 
 Q. Does solid shot jam in the bore of a gun? 
 
 A. They may do so if made of very soft iron and fired with very quick 
 powder. Rifle shot are more liable to upset than round shot. 
 
 Q. What was the character of the fracture in these guns which burst? 
 
 A. That of the 13-inch gun before referred to. 
 
 Q. What is the usual character of the fractures of solid cast guns that 
 have burst when fired with solid shot? 
 
 A. Very much the same, as far as I have observed, as shown in my 
 printed reports. 
 
86 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 Q. What is your theory to account for the bursting"? 
 
 A. That they have an adverse initial strain where the metal is good. 
 
 Q. Where a gun burst from the jamming of a shell in the bore, is the 
 pressure indicated by your instrument largely increased*? 
 
 A. Certainly if the gun has not been previously injured. 
 
 Q. I observe that the 12-inch rifle which burst at Fort Monroe endured 
 a pressure of 62,000 pounds without bursting or apparent injury to the 
 gun, while it afterwards burst under a pressure of about 49,000 pounds. 
 
 A. I can only account for that on the supposition that the large press- 
 ure and previous service to which it had been previously subjected had 
 weakened the gun, so that this pressure of 49,000 pounds being continued 
 by the jamming of the shot for an unusual length of time, burst the gun. 
 
 Q. Is it your opinion that the explosion of a sfyell just within the muz- 
 zle of a gun would rupture it? 
 
 A. It would depend entirely upon the circumstances of the bursting 
 of the shell and the strength of the gun at thaj point; the tendency would 
 be to unduly increase the strain upon the gun ; it might or might not 
 break it. 
 
 Q. Do you think that a gun strained at one fire by a pressure to nearly 
 the breaking point, will burst with a less pressure at a subsequent fire? 
 
 A. Yes ; continued firing with a less pressure will burst it, and it may 
 be at a very few rounds. 
 
 Q. Then the fact that a gun may endure great pressure at one fire is 
 no indication that it will endure a subsequent fire ? 
 
 A. No; and hence it is that we have abandoned the old method of 
 proving with double charges. A gun has so much work or endurance 
 in it; it wears out, like anything else. 
 
 Q. Why have no experiments been made to ascertain the exact effect 
 of such casualties upon the guns ? 
 
 A. I cannot give any other reason than that there has -not been time 
 for it as yet. That is owing to obstacles of one nature or another interven- 
 ing to prevent it. There has been much done towards perfecting ord- 
 nance, and there is still much to do. 
 
 Q. Have you ever estimated the amount of work exerted on the entire 
 bore of a gun, with a tendency to rupture it, for each degree the bore is 
 increased in temperature ? 
 
 A. No ; I have not. 
 
 Q. If the force of the powder alone was nearly sufficient to burst the 
 gun, would not the addition of a small amount of expansive force be 
 enough to rupture it ? 
 
 A. It might do so if the initial strain on the gun was too great, but 
 would not do so where the initial strain is too small ; the expansion of 
 the interior of the gun from heat in firing being advantageous to guns 
 having too little initial strain, and injurious to those having too much ; 
 and the expansion of the interior, due to the heat from firing, should be 
 taken into the account in fixing the initial strain upon the gun, and a 
 margin left for its action that is, the initial strain should be so great as 
 to bring the interior and the exterior to the breaking point simultaneously 
 under the addition of external strain that should be imparted by heating 
 the interior in firing the gun. 
 
 Q. What is the greatest endurance, by number of rounds, any 8-inch 
 Rodman rifles have endured ? 
 
 A. But two 8-inch Rodman rifles have been fired to extremity ; the 
 best one endured 1,047 and the other, I believe, 80 rounds the latter 
 being fired with grooved projectiles. 
 
 Q. Do you know anything about the endurance of the Ames gun, 
 
EXPERIMENTS ON HEAVY ORDNANCE. * 87 
 
 made of wrought iron, as compared with the 8-inch Rodman, as relates to 
 the average amount of work stored up in projectiles of each from an 
 equal number of the best examples of each kind of gun ? 
 
 A. A 7-inch wrought-iron gun made by Mr. Ames, was fired, I think, 
 about 700 rounds as a 7-inch gun, and was then reamed out to 8 inches, 
 and fired 24 rounds as an 8-inch gun, when it burst. 
 
 Q. Was that the best example of the Ames system of guns, as to 
 endurance ? 
 
 A. Yes ; of 14 other gu,ns (7-inch) offered, two burst in the proof, one 
 at the first and the other at the eighth round. 
 
 Q. Is that the one fired at Bridgeport? 
 
 A. Yes ; the one that burst at the 724th fire is. 
 
 Q. What was the size of the charges ? 
 
 A. I do not know the size of the charges. I have examined the frac- 
 ture of this gun. I folind two or three quite deep fissures on the interior 
 of the bore; and that on the fractured surface, which was transverse, 
 the breech blowing off, there was a surface, I should say, four inches 
 wide and 12 to 16 inches long, in which the weld was so slight as not to 
 amount to a weld at all. 
 
 Q. I see by a report that a board of officers have recommended the 
 purchase of 10 20-inch guns, 190 15-inch, 600 13-inch guns, all smooth-bore; 
 200 12-inch, 610 10-inch guns, rifles, for the armament of the fortifica- 
 tions, which requisition has been approved by the Chief of Ordnance. Do 
 you think that past experience with guns of these calibres, either rifles 
 or smooth-bores, warrants the purchase of them for use in forts or on 
 ship-board without further and more thorough experiments, and without 
 the discovery of some means to make their endurance more reliable ? 
 
 A. My impression is that the Chief of Ordnance did not approve the 
 requisition as to heavy rifle guns referred to in your question. It is a 
 question of public econcmy as to whether a nation should arm with cast- 
 iron guns, known to be reliable for a certain number of rounds., or go to 
 the expense of building up guns, or making steel guns that might stand 
 a greater number of rounds. My belief is that for the present our cast- 
 iron guns will do a given amount of service for less money than any other 
 gun you can get; for rifle guns, I do not know that cast iron will so com- 
 pare with steel guns or with built-up guns, as made in England, as to 
 justify their adoption without further trial. My belief is that no nation 
 has yet decided definitely upon what is the best material for rifle guns, 
 taking into account their cost as compared with others. Experimental 
 rifle guns have been recommended by the ordnance board and approved 
 by the Chief of Ordnance, and, I believe, by the Secretary of War. It is 
 contemplated that experiments with them shall be made before the pur- 
 chase of any large number of rifle guns for service, and the Chief of Ord- 
 nance so recommended in his annual report of 1867. 
 
 Q. Do you intend to say that the experiments with Eodman guns, both 
 smooth-bore and rifle, in service and in experimental firing, has demon- 
 strated with any certainty what endurances can be predicted for any 
 given gun ? 
 
 A. I do. 
 
 Q. Could you now predict a certain endurance for the 12-inch gun 
 recently fired at Fort Delaware ! 
 
 A. I could not, for the reason that I know that that gun has been 
 unduly strained, and I do not know to what extent. 
 
 Q. I mean only, in speaking of predicting a certainty of endurance, 
 that all contingencies to accidents liable to occur shall be taken into 
 consideration I 
 
88 * EXPEEIMENTS ON HEAVY ORDNANCE. 
 
 A. My belief is that after we shall have procured a projectile that is 
 as certain in its operation in the rifle gun as the round shot is in the 
 smooth-bore, that we can, by firing to extremity one or two 12-inch guns, 
 fix a limit within which the gun may be considered as absolutely safe, 
 but it will require experiment to fix that limit. 
 
 Q. Why do guns of smaller calibre have so much greater endurance 
 than guns of larger calibre ? 
 
 A. For the reason that the pressure of gas upon them is less per square 
 inch. , 
 
 Q. Do you not increase the strength of the gun in proportion to the 
 increase in the pressure of the gas I 
 
 A. No ; it is not expedient to do so. We adopted a different course 
 to meet this difficulty ; we used a slower burning powder, which should 
 give a less maximum strain upon the gun, and a greater terminal strain 
 than could be obtained with quick burning powder ; and increase the 
 length of the bore of the large guns, so that under the more uniform 
 action of the gas over a longer distance, and during a longer space of 
 time, we impart to the projectile velocities nearly if not equal to those 
 obtained in smaller guns, with powder heretofore used in them; and, in 
 fact, we now secure greater velocities from a 15-inch gun than we for- 
 merly did from 10-inch. 
 
 Q. If the restraining force in a large gun is increased in proportion to 
 the increase of force to be restrained, as your reply would indicate, then 
 why is the large more liable to break than the small one! 
 
 A. With the charge and kind of powder that we use in a large gun, I 
 do not think it is more likely to break, other things being equal. It is 
 more difficult to get a perfectly safe projectile for a large gun than for a 
 small one. 
 
 Q. Could you not so increase the thickness of the walls of the gun, and 
 thus increase its restraining power, as to allow for the jamming or friction 
 of the projectile ? 
 
 A. I have no doubt that that might be done to a greater or less extent, 
 by the hollow mode of cooling. A 10-inch gun, two calibres thick, cast 
 solid, will not, in my opinion, be as strong as a gun one calibre thick, 
 owing to the adverse initial strain imparted to it from the external 
 cooling. 
 
 Q. Do you assign any other cause for rupturing of guns besides the 
 premature explosion of shells and the wedging of projectiles ? 
 
 A. I do not think of any other, except a variation or want of regularity 
 in the quality of the powder used, or the existence of adverse or im- 
 proper initial strain in them. I regard the subject of powder as of equal 
 importance in the endurance of guns with the strength of the gun itself. 
 
 Q. Please read the following paragraph in the report of the Chief of 
 Ordnance of the navy, as to the knowledge or lack of knowledge pos- 
 sessed by the navy on the subject of ordnance, and say if any more 
 knowledge is in your opinion possessed by the ordnance department of 
 the army ? 
 
 A. In my judgment, we do know that the main portion of our arma- 
 ment of the forts ought to be smooth-bore guns, rather than rifles; the 
 living force imparted to a shot by our largest smooth-bore guns cannot 
 be with equal safety imparted to a rifle shot. The accuracy of 15-inch 
 and 20-inch guns is, in my judgment, equal to that of any rifle we have 
 at the distance of 2,000 yards, and that of 20-inch guns, especially, at 
 greater distance. I think we do know that more reliable guns can be 
 made of cast-iron than of wrought, intended to be in one piece, in the 
 present state of the art of forging. I would also state, that if I were 
 
EXPERIMENTS ON HEAVY ORDNANCE. 89 
 
 going to remodel our heavy guns, I should make them heavier than they 
 now are, our present model havdng been fixed in reference to the gun- 
 carriages on hand for 10 inch guns; for 15 and 20-inch I should increase 
 the weight, I think, certainly 25 per cent.; not only for the purpose of 
 giving strength to the gun, but to diminish the injurious effects of the 
 recoil upon the carriage and the platforms. I think experiments on 
 powder, with a view to determine the best form in which to place it, 
 ought to be made, as well as experiments continued on guns, for the pur- 
 pose of determining the safe endurance of those we have on hand, and 
 the proper material, models and forms of guns, for their respective 
 projectiles. 
 
 Q. In a report made by yourself in 1857, wTien a captain of ordnance, 
 you make a statement in regard to important things connected with gun- 
 making, of which you possess no positive knowledge. Have your subse- 
 quent experiences thrown any light upon this question I 
 
 A. They have. I have no doubt now that the strongest cast-iron, 
 having the greatest elasticity, hardness, and extensibility, when cast 
 into a gun, cooled from the interior, as they are now cooled, will make 
 the best gun. I have no doubt either, now, as to whether guns should 
 be cast solid or hollow, being satisfied that they should be cast hollow. 
 I also feel satisfied that we know more about the proper model of a gun 
 than we did at the time, that report was written ; we know better how 
 to determine the model of a gun for a given weight of metal and diame- 
 ter of bore. We do know with sufficient accuracy for practical purposes, 
 the statical pressure due to a given wei'ght of powder and shot. We have 
 also acquired knowledge as to the effect in endurance of the rapid appli- 
 cation of charges exerting different degrees of strain upon the gun. We 
 have also acquired knowledge as to the proper constitution of the charge 
 to produce a given velocity of shot, with a minimum strain upon the gun. 
 
 JANUARY 28, 1869. 
 
 Bear-Admiral JOHN A. DAHLGREN sworn and examined. 
 By the CHAIRMAN : 
 
 1. Question. State when you took charge of the Ordnance Bureau of 
 the Navy Department. 
 
 Answer. In April, 1861, the command of the navy yard at Washing- 
 ton devolved upon me, all the other officers having deserted it. In July, 
 1862, I was directed to take command of the Bureau of Ordnance by the 
 Secretary of the Navy. In July, 1863, I was assigned to the command 
 of the South Atlantic blockading squadron. In June, 1865, I returned 
 north, and the war of the rebellion being closed, I was detached from 
 the squadron which I commanded. In December, 1866, 1 took command 
 of the South Pacific squadron. In August, 1868, I was detached from 
 the command of that squadron, and ordered by the department to take 
 charge of the Bureau of Ordnance. 
 
 2. Q. Have you given especial attention to the subject of the fabrica- 
 tion of guns ! 
 
 A. I have; and I believe there are very few officers of our navy who 
 have had as much experience as I have had. 
 
 3. Q. Are you the inventor of a system of gun-making, or the designer 
 of a model for guns ? 
 
 A. I am the inventor of a system of armament for our navy generally, 
 including the guns and carriages to be used in it; also of a system of 
 naval light artillery, including carriages and appliances. The character 
 
I 
 90 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 and some of the services of this ordnance may be noted from the opinions 
 of distinguished officers immediately at hand, viz : 
 Admiral Dupont says : 
 
 But, besides this, I am impelled by a feeling of duty to address you. The large ordnance 
 of this squadron has sprung from your inventive genius ; and thankful am I for one for 
 those long years of study, scientific research and deductions which have so materially aided 
 in arming the American navy as I believe no other navy is armed. 
 
 Do you remember after I came from China my writing you how much I thought of the 
 ^Minnesota's gun deck battery, (9-inches. ) In your reply you modestly seemed to think 
 their days were numbered. I only now wish you could have seen the practice from this ship 
 during the engagement, not alone for its precision and destructive results, but for the rapid- 
 ity with which such large guns could be loaded with their heavy shell. I never get trans- 
 portS, as the French term it, about such things, but I will repeat, to the day of my death, 
 that the second assault of this ship upon the forts for rapidity, continuity, and precision of 
 fire has not been surpassed in naval warfare. Extract from letter of November 24, 1861. 
 
 Commodore Bodgers says : 
 
 I saw the terrible effect of the Wabash battery at Port Royal ; it was so rapid in its fire 
 that the rebels on shore reported in their papers that the Wabash was twice on fire ; it was 
 merely the flames coming out from her batteries. I took a powerful spyglass and looked 
 through it, and saw the shells falling at a rate that perfectly astonished me ; so that nothing 
 could live there. The men were driven away from their guns. Testimony before, the Com- 
 mittee on Conduct of the War Heavy Ordnance, p. 80. 
 
 Assistant Secretary Fox says : 
 
 The best shell-gun is Admiral Dahlgreii's nine and eleven-inch guns. Testimony 
 before Committee on Conduct of the War Heavy Ordnance, p 170. 
 
 Commodore Alden says : 
 
 Question. What number and calibre of guns had you on board the Brooklyn in your expe- 
 dition against Fort Fisher? -Answer. We had twenty 9-inch guns, two 10!J-po under Par- 
 rotts, and two 60-pounder Parrotts all four of the Parrotts rifled. 
 
 Q. How many times were those guns fired in the two attacks upon the fort? A. I threw 
 into that fort 3,40..; nine-inch shells, over 120 tons. 
 
 Q. How did the guns bear that shelling? A. As soon as I heard of the 100-pounder 
 bursting, I put mine on the opposite side of the ship from that with which I was fighting, 
 and put in their places the nine-inch guns, so that I had 12 nine-inch guns in battery all the 
 time. 
 
 Q. Then you did not use those 100-pounder Parrotts ? A. Not after I heard of the acci- 
 dents with them on the other ships. I never fired them again. 
 
 Q. Were those nine-inch guns made on the Rodman principle? A. They were Dahlgren 
 guns. 
 
 Q. Were they cast hollow or otherwise ? A. They were the Dahlgren nine-inch guns ; the 
 best gun ever made. 
 
 Q. What effect had that firing upon them ? A. I never discovered that any of them were 
 injured. 
 
 Q. Did none of them fail ? A. Not in the slightest degree. The men stand around them 
 and fight with them with as much confidence as they drink their grog. * 
 
 Testimony before the Committee on Conduct of the War Heavy Ordnance, p. 172. 
 
 Captain Wise, Chief of Bureau of Ordnance, says : 
 
 During the recent rebellion the cast-iron, smooth-bore guns of the navy endured all the 
 severe service to which they were subjected, and proved their excellence everywhere and 
 under all conditions of actual war. Not a single gun of the Dahlgren system has burst 
 prematurely. * * * 
 
 While the practice at the test battery against armor plating shows that even the 1 1-inch at 
 close quarters is capable of piercing any thickness of iron or steel with which the sides of an 
 ordinary cruiser, intended to keep the seas, could be covered with safety, and this without 
 any danger of rupture from the use of increased charges, unless the gun has been very much 
 weakened by previous service. * * * 
 
 Annual report to Niivy Department, November, 1865. 
 
 Vice- Admiral Porter says : 
 
 The gun which I deem best adapted to general use in the navy is the 11-inch gun, which 
 can be carried on board even our smallest vessels, worked in a sea way, if the vessels are 
 properly constructed, and almost as rapidly as a 34-pounder; at all events rapidly enough 
 for all practical purposes. 
 
 I consider its accuracy much greater than any rifle gun, or any gun of a smaller calibre. 
 That, I believe, has been tested to the satisfaction of most navy officers. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 91 
 
 I remember once on an occasion having used 30 pounds of powder, when the service 
 charge was only 15. You may remember that I drew the attention of the bureau to this at 
 the time. Some thought that I was giving the gun more powder than it would stand. I 
 recollect on the above occasion I attained great range, and prevented myself from being 
 annoyed by some'rebel gunboats provided with small rifle guns of considemble range. See- 
 ing the great range obtained with my 11-inch gun, they let me alone. I could not follow 
 
 them, as there was a bar between us. 
 
 ******** 
 
 That most important power, ricochet firing, is entirely lost in the rifle guns ; and in a 
 sea way a vessel armed with 11-inch guns is, in my opinion, a match for a vessel with twice 
 
 the number of rifle guns. 
 
 ******** 
 
 I have never to my knowledge known an accident happen to the 9-inch, 10-inch, or 11-inch 
 guns, three of the best guns we ever had in our navy ; and in battle men stand behind these 
 
 guns in perfect security, knowing that the chances of their bursting are very small. 
 
 * *** * * * * 
 
 Against wooden vessels nothing is equal to 11 inch guns, and I believe that a small and 
 fast vessel that could choose her distance, carrying a couple of 1 Much guns, could 
 damage seriously, if not drive off, the largest ship in the British navy armed as they were in 
 1861. I believe, moreover, that an 11-inch gun, firing a solid steel ball, would smash in the 
 Bides of some of the heaviest English iron clads, and would damage very seriously the 
 turrets of some of our heaviest vessels Extract from letter, January 15, 1SG9. 
 
 4. Q. What is the method of the fabrication of a gun of large calibre 
 in your system? 
 
 A. The largest calibre which I proposed to use in wooden vessels is 
 the 11-inch gun. At that time there were no iron-clads in existence. 
 The casting of the gun was to be solid nearly of equal diameters, and 
 tapering from the breech to the chase, nearly the diameter of the gun at 
 the breech, but very much smaller than the diameters of the finished gun 
 at the chase; the object being to produce as much uniformity in cooling 
 as is desired. This casting was afterwards to be turned down to the 
 dimensions required for the gun, preferring to leave the skin of the cast- 
 ing on the cylinder and the breech of the gun, which, however, was not 
 always done. 
 
 5. Q. From your experience, what do you consider to be the relative 
 endurance of guns cast solid, of the model described, as compared with 
 guns cast hollow, on the system of General Eodman 1 ? 
 
 A. We have the practical results of a large number of guns cast for 
 the navy in the way that 1 have described smooth-bores of 9 and 11- 
 inch calibre; they have withstood all the tests of battle during the war 
 of the rebellion, 1 believe, with hardly an exception. These cannon 
 have done all the service that was required of them; were used in almost 
 all our actions ; in the great battles of Dupont, Farragut, Porter, &c. 
 Many of the 11-inch have been frequently fired with charges very much 
 above those designed for them, viz, 15 pounds, which is all that was 
 really necessary for eifect against the strongest wooden vessel. Being 
 suddenly brought into the war of the rebellion, and being compelled to 
 use these guns against iron plating, heavier charges were frequently 
 resorted to. I may refer to the action at Mobile, where Admiral Far- 
 ragut hauled up alongside the rebel ram Tennessee; he used much 
 heavier than the ordinary charges. I have myself fired 11-inch guns 
 in experimenting at iron plating with solid shot and 30 pounds of powder, 
 which w^as mo?e than double the strain that the gun was intended to 
 stand. One of them was fired in this way about 200 times and did not 
 burst. I think, therefore, that it can be said that the form of my guns 
 and the method of casting them are fully equal to every requirement of 
 the severest service. The history of the past shows no endurance of 
 other cannon equal to that of the 9 and 11-inch guns. Nothing has been 
 more common in the great naval actions of the European naval powers 
 
92 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 than the bursting of cannon and the loss of life consequent thereon. 
 The records of our own navy are not without such accidents. In the 
 celebrated fight of Paul Jones with the British frigate Serapis, some of 
 his lower deck guns burst, " bio wing up the deck above and killing or 
 wounding a large proportion of the people that were stationed below. 
 This disaster caused all the guns to be instantly deserted, for the men 
 had no longer confidence in their metal. It at once reduced the broadside 
 of the Richard to about a third less than that of her opponent, not to 
 include the disadvantage of the manner in which the force that remained 
 was distributed amon g light guns. In short, the combat was now between 
 a 12-pounder and anl8-pounder frigate." Cooper's Naval History, p. 106. 
 I have no doubt that the same method of casting and fabricating the 
 9 and ll-inoh guns could be used in making the largest calibres; but to 
 do so it will be necessary to obtain a competent knowledge of the kinds 
 of iron that are to be used in the foundries for this purpose. 
 
 6. Q. Have smoothbore guns cast upon your system, with like charges, 
 manifested greater endurance and serviceability than guns of like calibre 
 cast according to the system of General Eodman ? 
 
 A. I believe that guns of 8 and 10-inch calibres as well as of 15-inch 
 have been cast hollow upon the plan of General Eodman, but they have 
 never been proved to the extent that solid-cast guns of 11-inch calibre 
 have been proved ; therefore, we do not positively know how great their 
 endurance really is. The endurance of a few guns cast with special 
 care under the superintendence of General Eodman is not to my mind 
 complete evidence of the endurance of a large number of guns of the 
 same kind cast at different foundries and taking the chances of the expe- 
 rience or want of experience of different founders and of various kinds 
 of iron. 
 
 7. Q. If you were now to re-arm the navy would you do so with guns 
 cast solid or hollow ? 
 
 A. If the guns were to be 11-inch, or of that weight, say 16,000 to 
 20,000 pounds, most certainly they should be cast solid, as they have 
 always been ; if above that weight, then I should proceed to experiment 
 with different kinds of iron, in the full belief that I should be as success- 
 ful with these heavy guns as with the 11-inch. The first trials of cast- 
 ing hollow guns of heavy calibre, by General Eodman, took place in 
 1849 and 1851. Six guns were cast, three hollow and three solid, in 
 pairs. Each hollow-cast gun endured a larger number of rounds than 
 its fellow cast solid. In all cases the solid guns were so bad that the 
 comparison only proves that two of the hollow-cast guns were better 
 than very bad guns that had been cast solid. Considering the hollow- 
 cast guns by themselves, it will be seen that two out of the three were 
 bad almost as bad as they could be, their endurance being so low. Only 
 one of the three proved to be a good gun ; it withstood 1,500 rounds, 
 and was not burst ; but every ordnance officer knows that it is not the 
 excessive endurance of one, or of a few pieces, that gives character and 
 confidence to a lot of guns 5 it is the uniform endurance of the whole, 
 even if that be not very high ; because it is the unforeseen bursting of 
 the gun that does the mischief in action. When General Eodman's hol- 
 low-cast guns did attain a good degree of uniformity it was with an 
 entirely different model ; and that model I claim as my own, and have f 
 so apprised the War Department. With this new model General Eod- 
 man made two 10-inch guns, putting them to an extreme proof, which 
 they endured to the extent of 4,082 rounds without bursting. The solid 
 gun was more indented at the seat of the shot than the hollow gun ; but I 
 think this to be of little consequence, because, in practice, a gun of 
 
EXPERIMENTS ON HEAVY ORDNANCE. 93 
 
 heavy calibre would be laid aside long before it reached 4,000 rounds. 
 I think the conclusions from these data are : 1st. That when the hollow 
 casting was used with the columbiad of old model it failed to make them 
 uniformly good. 2d. When the columbiad was shaped after my model 
 the guns were as good when cast solid as hollow. I think the whole 
 question of rifled guns is open ; I do not think that anything is known 
 about it, either in wrought or cast iron. I know of nothing in foreign 
 countries in which I believe they have really reached better results than 
 we have here. But a few days since I observed in the newspapers that 
 one of the English guns that they had relied on so much had given way, 
 (the Fraser gun.) 
 
 8. Q. Have experiments in this country demonstrated, as yet, that 
 large rifle guns can be made according to the Rodman system with a 
 reasonable certainty of endurance ? 
 
 A. I think not. 
 
 9. Q. How will it compare in rifles with the solid mode of casting? 
 A. The solid casting has given no better results with rifled cannon 
 
 than the hollow. 
 
 10. Q. What is your opinion as to the correctness of the Eodnian 
 theory of gun-making ? 
 
 A. At first sight it seems to be well founded ; but I think that a full 
 consideration would show that it is quite as open to objection as any 
 other, and even more so. Some of my opinions on this subject will be 
 found more at length in a paper annnexed, marked note A. 
 
 11. Q. Has this system ever been adopted in the navy ? 
 
 A. Only in the casting of 15-inch guns. That was done under very 
 peculiar circumstances. The Navy Department had ordered 15-inch guns 
 to be put into the first monitors. At that time we had no iron-clads, and 
 the rebels had suddenly precipitated one upon our blockading squadron 
 at Hampton roads, destroyed two frigates, threatened to break up the 
 blockade there, and the plan of the campaign which was just about to 
 move under General McClellan down the Chesapeake against Eichmond. 
 The rebels were known to have iron-clads in readiness at other places. 
 There was no time for experimenting with the 15-inch cannon ; it only 
 remained for us to do the best we could. There had been but one gun of 
 the kind made at that time; it had been cast hollow, and had endured 
 a proof of about 500 fires, but with inferior charges; when, therefore, I 
 sent the draught for the navy 15-inch gun to the bureau, I advised the 
 bureau to have those guns made exactly as the first 15-inch gun had been 
 .made, the hollow casting included, until there was time for experi- 
 ments w T ith other methods. 
 
 12. Q. With what description of guns is the navy now provided; that 
 is, as to methods of manufacture? 
 
 A. The heavy guns of the navy are the smooth 9, 10, 11-inch guns, all 
 of my own system, and cast solid; the navy 15-inch, cast hollow, and 
 the Parrott 100-pounder rifle cannon. The 150-pounders have been with- 
 drawn from the naval service. (See note B.) 
 
 13. Q. Have you any other rifled guns besides the 100-pounder 
 Parrotts 1 
 
 A. No other. Opinion has very much changed in our navy since the 
 beginning of the war of the rebellion as regards the value of rifled guns. 
 Then the demand was incessant. The idea seemed to be prevalent that 
 smooth-bore cannon could not be pitted against rifle cannon under any 
 circumstances. I think that sentiment is very much changed. My own 
 experience, from repeated action, induces me to give preference to heavy 
 smooth-bore guns. I always thought that they hurt our iron-clads more 
 
94 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 in battle than the rifles did, and I am inclined to believe that the same 
 opinion prevails largely in the navy, independently of the distrust of the 
 rifle guns which we now have. 
 
 14. Q. Have not these changes in the views entertained in the navy 
 with respect to rifles been largely owing to their unreliability f 
 
 A. I think they have ; but independently of this I have seen instances 
 where the power of the 11-inch and the rifled 150-pounder were in direct 
 contrast. A number of officers and men witnessed the practice at long 
 range of both. 1 allude more particularly to a case in battering a work 
 on the Stono river. 
 
 15. Q. Were not the Parrott rifles condemned by the board of ordnance 
 officers u ? 
 
 A. The 150-pounders were recommended to be withdrawn by a board, 
 which was done. The bureau also reduced the charge of the 100-pounder. 
 (See Report of Bureau, 1865.) 
 
 16. Q. If the condemnation extended to all guns made by Captain 
 Parrott, why have they been retained in service f 
 
 A. It did not extend to 100-pounders or to rifled guns of less calibre. 
 
 17. Q. Do you think the 100-pounders reliable guns I 
 A. I should be apt to handle them very carefully. 
 
 18. Q, Have any Parrott guns burst in the naval service since the 
 conclusion 'of the war ? 
 
 A. Yes ; a rifled 30 pounder burst recently in the South Pacific squad- 
 ron, which I just left. I do not think the number of rounds had amounted 
 to 200. I reported it to the Secretary of the Navy, and told him we 
 had no rifle guns in the navy that were reliable,* asking leave to pro- 
 ceed to investigate the question and ascertain if reliable rifle guns could 
 be procured. 
 
 19 Q. What is your opinion of the utility of guns as large as those of 
 15 and 20-inch calibre, as compared with smaller calibres ! 
 
 A. I was not of the opinion that the 15-inch gun was most suitable 
 for the navy. I doubted if sufficient charges could be used to drive a 
 shot of that size with the required velocity, having proper regard, first, 
 to the endurance of the gun, and then to the endurance of the carriage. 
 It is considered advisable to check the recoil by mechanical means ; and 
 it is doubtful if they would long endure the enormous strain of very 
 heavy charges. A lower calibre than 15-inch, with a higher charge, 
 might be sufficiently effective against iron-plating. I was conducting 
 experiments to that end in 1863, when I left to go to sea, and had driven 
 a 10-inch shot through six inches of iron at 200 yards, with a smooth- 
 bore of 10 inch calibre. 
 
 20. Q. How does rapidity of fire, other conditions being equal, affect 
 the result of battles, ship against ship, or ship against works on the 
 shore ? 
 
 A. Of course the more rapidly that successive blows could be struck 
 the sooner will the result be reached ; but the safety of the gun is to be 
 considered, as the bursting of a 15-inch gun on board of a ship would 
 be very fatal. 
 
 21. Q. What is the heaviest calibre of gun compatible with rapidity 
 of fire and mounting, in numbers, 011 the broadside of ships I 
 
 A. In my system of naval armament I take the ground that the 
 heaviest guns should be used which can be worked upon the broadside 
 carriages, and for pivot guns that throw the heaviest shot that can be 
 handled at sea ; the rapidity of fire of such cannon is quite sufficient 
 
 * This does not include our rifle boat-guns, which are good enough. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 95 
 
 under the most favorable circumstances, the gun not being trained or 
 pointed, nor the elevation changed. An 11-iucli gun can be fired on a 
 fixed platform once a minute ; but I doubt if this can be done on ship- 
 board in action ; certainly not continued for much time. 
 
 22. Q. How rapidly are 15-inch guns in monitor turrets fired ? 
 
 A. My recollection of that is not very clear ; in action there were 
 always other objects to take off my attention $ but so far as I do remem- 
 ber I think it required between five and six minutes to fire a shot j that, 
 however, included the revolution of the turret from the enemy's battery 
 and back again. Moreover, the person who fired the gun could never 
 see the object, but was directed in his aim by another person at a tube 
 in the side of the turret. Then there was time lost by giving the word 
 to the engineer, who worked the lever for turning the turret ; all this 
 and the swaying of the vessel must be counted in the time of firing. 
 
 23. Q. Are rifie or smooth-bore guns most effective against iron plat- 
 ing, if the weight of the gun and projectile are alike, and the initial 
 velocity is the same from both kinds of guns ? 
 
 A. Supposing shot of equal weight to strike with equal velocity, 'I 
 should prefer the round shot ; but this is open to opinion and further 
 experiments. 
 
 24. Q. Have any experiments been made to ascertain the effect uon 
 guns of the premature explosion of shells within their bores f 
 
 A. I remember trying one such experiment with an 11-inch gun. 1 
 think it was evident in some cases that the shell was not burst in the 
 bore of the gun, by arrangements that were made for the purpose. In 
 the other cases the shell had burst in the gun. The gun was unhurt, 
 but the number of rounds were small five or six. Still, I have a very 
 strong doubt if the bursting of shells in guns are the cause of the 
 repeated splittings of the chase that are reported. 
 
 25. Q. Do you attribute the rupture of guns to that cause if a gun 
 gives way in the rear of the trunnions f 
 
 A. If a cannon gives way in the rear of the trunnions it must be 
 owing solely to its inability to withstand the charge with which the gun 
 has been fired j but a gun might have such bad metal in front of the 
 trunnions that it would crack from the bounding of the projectile in 
 connection with the bursting of the shell. I have never seen a gun 
 myself that I thought was split in the chase by the bursting of shells. 
 
 26. Q. How do you account for the blowing off of the muzzle in the 
 15-inch gun! 
 
 A. If a gun had previously been cracked in the chase, the force of the 
 charge and bounding of the projectile might subsequently be sufficient 
 to break the chase and blow the pieces in front. 
 
 27. Q. Does increasing the thickness of the wall of the gun beyond 
 a certain limit increase the strength of the gun f 
 
 A. I think not. I think there is a thickness of metal, taken in con- 
 nection with the process of founding, which will give a greater strength 
 to a gun, within certain limits j of course a gun might be made so extra- 
 ordinarily thick that no charge could burst it. 
 
 28. Q. Does the strongest iron always make the strongest gun ? 
 
 A. There was an idea prevailed, when I first became connected with 
 the ordnance, that the quality of iron for guns was invariably indicated 
 by a certain degree of tensile strength and density, without reference to 
 the different qualities of iron. To this I never agreed j and I am inclined 
 to believe that the advocates of the theory are pretty well satisfied that 
 it was not well founded. I, myself, have always used the tension strain 
 and density as measures of uniformity simply j that is, when a good gun 
 
96 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 had been obtained from any kind of iron, the tension strain and density 
 of its metal, in connection with other signs, were to be followed in other 
 guns of the same class cast from the same kind of iron. The kinds of 
 iron differ very much, and hitherto we have been able to obtain good 
 guns from all of them by varying the treatment. 
 
 29. Q. Are there any means of ascertaining, with approximate accu- 
 racy, the pressure of the gases of gunpowder on the bore of a gun ? 
 
 A. I do not think there are. General Kodman has a method which 
 he relies on, and which, I believe, is confided in by the War Department. 
 But I confess I never did rely upon it as entirely accurate. There were 
 experiments tried for this purpose by Colonel Bomford, very many years 
 ago, by boring a hole along the line of a gun to measure the force with 
 which the gases issued from these apertures. This idea has often been 
 attributed to myself, and is said to have been the basis of the form 
 which I have used for cannon ; which is eKtirely incorrect. The idea 
 belongs to Colonel Bomford, and the form of my cannon are the results 
 of reasoning entirely. The draught of the first 11-inch gun is the same 
 that is now used. I never altered it in any respect, except to remove 
 the swell of the muzzle from the end of the gun, for more convenient 
 use in the narrow ports of iron dads. 
 
 30. Q. Is the range for an 11-inch gun, with light charge, so nearly 
 uniform as to justify the belief that the pressure of the gases of the 
 powder is nearly uniform in the gun $ 
 
 A. I have no means of answering this question positively. The 
 ranges of the 11-inch guns, with the regulation charge of 15 pounds, are 
 very uniform, and I think more accurate than any other smooth-bore 
 gun of the same description and calibre. 
 
 31. Q. Have you ever determined, by experiment, the ratio of increase 
 of the pressure of gasses of powder in a gun, if the weight of the pro- 
 jectile is increased 1 ? 
 
 A. I never have, nor do I think there are any means by which that 
 could be ascertained. We know, generally, that the pressure upon a gun 
 increases in a much higher ratio than the weight of the charge of the pow- 
 der j that is to to say, if you double the weight of the charge you would 
 very much more than double the strain upon the same gun. 
 
 32. Q. Would the pressure of the gas evolved from the powder upon 
 a square inch of the surface in a chamber of the same diameter be less 
 or greater than the pressure per square inch in a large chamber ? 
 
 A. I do not think that we have any means of determining these results 
 with any accuracy. 
 
 33. Q. Have any experiments been made to determine the increase of 
 strain upon the* bore of a gun by not having the shot home against the 
 powder charge ? 
 
 A. I think, many years ago, that Commodore Stockton made some 
 experiments of that kind. The general impression is that there should 
 be no space between the charge and the shot, as it strains the gun more. 
 
 34. Q. Do you know the comparative tensile strength and density of 
 the iron used in the long 68-pounder and the Dahlgren 9-inch gun $ 
 
 A. 1 do not 5 but believe that the metal of the English 68-pounders 
 has always been inferior to that of our 9 and 11-inch guns. 
 
 35. Q. It is stated that the tensile strength of the long 68-pounder is 
 about 18,000 pounds, while that of the 9-inch gun is 30,000. 
 
 A. The tensile strength of the United States guns varies with different 
 irons. We have had excellent iron where the tenacity was 25,000 pounds, 
 while the West Point and Boston iron was giving good metal at 30,000 
 to 35,000 pounds; but the English establishment failed so badly with 
 
EXPERIMENTS ON HEAVY ORDNANCE. 97 
 
 their 68-pounders that it was thought to have been one of the causes that 
 led to the substitution of a scientific civilian like Sir William Armstrong 
 for the officer in charge of the government foundry, a measure which 
 worked badly in all respects, particularly in cost. 
 
 36. Q. What is the least tensile strength permitted to be used in the 
 11-inch Dahlgren guns? 
 
 A. That would depend entirely upon the tenacity exhibited by a good 
 trial gun. If such a gun were made at Boston, the iron they use would 
 probably exhibit a higher strength, elsewhere a lower. I had some diffi- 
 culty in that respect with some of the 15-inch guns that were made at 
 Pittsburg, and had a correspondence with the founder on that subject 
 he having varied considerably from the density of the trial gun, which I 
 insisted he should adhere to within certain limits in order to preserve 
 uniformity with the trial gun. 
 
 37. Q. Do you think the tensile strength of the iron has comparatively 
 little to do with the endurance of the gun ? 
 
 A. It is necessary to maintain it in that degree, which is ascertained 
 by trial to belong to the kind of iron used. 
 
 38. Q. How do you account for the apparent anomaly referred to in 
 Eodinan's book, where he says the strongest iron does not make the 
 strongest gun, and where he states that having too much density 
 resulted in reducing the endurance of the gun? 
 
 A. The iron of the highest density does not always make the strongest 
 gun. 
 
 39. Q. Will the charge now prescribed for the navy gun give the 
 highest attainable velocity to the shots ? 
 
 A. The regular charges for the 9-inch and 11-inch guns will give all 
 the velocity required to do the work for which these guns were designed; 
 that is, the destruction of wooden vessels. They will bear much higher 
 charges I should say one-half higher ; and there is an order at the 
 bureau authorizing 30 pounds to be used with the 11-inch guns in special 
 cases. 
 
 40. Q. Will they bear 50 pounds of powder? 
 
 A. The carriages would not very long, and it is not necessary that the 
 guns should, for the purposes for which they were made. 
 
 41. Q. Will they endure the charges necessary to give the highest 
 velocity to the projectile ? 
 
 A. The 11-inch can be safely used as high as 25 pounds, and even to 30 
 pounds, which is double the charge for which the gun was designed. 
 
 42. Q. How do the highest charges successfully used in these guns 
 compare with the charges successfully used in the Armstrong guns ? 
 
 A. I am not sufficiently informed in regard to the Armstrong guns to 
 answer accurately ; but we do know that the Armstrong guns have been 
 laid aside, and that the 9-inch and 11-inch guns are not. 
 
 43. Q. You have said that a 100-pounder is the only rifle cannon in 
 the United States naval service ; what is its ability to stand heavy 
 charges, compared with other rifles? 
 
 A. I am unable to say. 
 
 44. Q. What is your opinion of the Ames system of making wrought- 
 iron guns? 
 
 A. It must be judged by its results; they are before the committee. 
 
 45. Q. Do you think the Ames guns are better guns than Parrott's? 
 A. Whatever may be said of the merits or demerits of the Parrott gun, 
 
 or the necessity for superseding it, no other rifle gun has yet obtained 
 sufficient confidence to take its place. 
 Rep. No. 266 7 
 
98 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 NOTE A. 
 [Despatch No. 576. ] 
 
 FLAG STEAMER PHILADELPHIA, 
 Port Royal Harbor, #. (7., November 20, 1864. 
 
 SIR : I have received but a few days since a communication from the 
 Bureau of Ordnance in relation to the casting of cannon of my design. 
 
 The nature of the recommendations therein made by the bureau to the 
 department seems to render it proper that I should address the depart- 
 ment directly. 
 
 The unceasing demands on my time and attention absolutely render it 
 impossible for me to reply to this communication as I would wish, 
 nor have I the documents at hand, if I had the leisure to use them. 
 I am, therefore, obliged to content myself with the following incomplete 
 expression of my views : 
 
 The 9-inch and 11-inch guns of my design have manifested all the en- 
 durance that has been required through a course of trial on the proving 
 ground, and through a course of service which has seldom, if ever, been 
 applied to any other cannon. 
 
 The endurance has never been approached previously by such heavy 
 calibres, and it has also been uniform, which is absolutely indispensable 
 to give value to any endurance, for it is the unexpected bursting of can- 
 non that does the mischief. 
 
 In trials made to test the strength of the 9-inch and 11-inch no gun 
 has ever fallen short of 1,500 rounds when fired with the charges for 
 which the cannon was intended, and I feel no doubt that if the firing had 
 been continued with service charges, the guns tried would have gone to 
 2,000 or 2,500 rounds. 
 
 This was never done, because no probable exigency would ever have 
 made such a demand on a single gun 5 extreme charges were therefore 
 substituted. Some of the cannon that have been so tested were at the 
 Washington navy yard, and unless removed are there still. 
 
 One of them, a 9-inch gun, was fired 1,500 times with service charges, 
 and still looks well 5 another was fired 1,500 times, and then with increas- 
 ing charges, until at the 22d of such fires there were 20 pounds of powder 
 and 90 pounds of shot in the gun when it gave way. 
 
 Many other cases of severe proof are recorded of the 9-inch guns. 
 
 The first 11-inch gun was fired more than 1,300 times with shell, and 
 about 650 times with solid shot of 170 pounds ; it burst at the 1,959th 
 round fire. Other 11-inch guns have been submitted to severe tests. One 
 was used for practice against iron plates with solid shot, and charges 
 increasing to 30 pounds, to the extent of 200 fires, and was in good order 
 when I left it. 
 
 It is to be borne in mind that these guns were not intended to be fired 
 with solid shot, and that previous to their advent 800 rounds were 
 looked on as a fair standard for heavy guns, such as columbiads. 
 
 In actual service the record of the 9-inch and 11-inch guns is unex- 
 ceptionable. 
 
 They have constituted the armament of our principal ships of war for 
 10 years. 
 
 They have been carried over the whole globe during more peaceable 
 times in those superb ships Wabash, Minnesota, &c., and now that 
 rebellion and disloyalty threaten the Union, they are identified with the 
 greatest glories of the flag. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 99 
 
 Admiral Stringham, at Hatteras ; DuPont, at Port Royal j Farragut, 
 at New Orleans and Mobile, illustrated their power against forts and 
 batteries, while the Kearsarge vindicated the principles of my system 
 generally against the matured conclusions of British authorities. 
 
 Hundreds of these guns have been cast and carried by vessels second 
 to none of their class ; in no one instance has a single 9-inch or 11-inch 
 cannon been burst on shipboard or a man hurt. One or two were split 
 at the extreme end near the muzzle, but this could only have arisen from 
 improper loading, and the guns were still capable of being used with 
 effect and safety. No officer hesitates to place confidence in his 9-inch 
 or 11-inch guns, and Admiral Farragut when engaging the Tennessee 
 shotted his 9-inch shell guns with one-third more powder than the usual 
 charges, and he was not mistaken, at least in their endurance. 
 
 These guns were, in the strictest sense, shell-guns. They were designed 
 15 years ago, when wooden vessels only wore to be the objects of 
 fire, and it was this extensive application of the shell power that caused 
 resort to iron plating to keep them out. 
 
 But so great was the strength which 9 inch and 11-inch guns proved to 
 have, that no hesitation existed in loading them with shot and higher 
 charges of powder for battering even iron plating, and the 11-inch guns 
 did good service to the country on more than one such occasion. 
 
 When the rebel rani Merrimack issued forth and inflicted such griev- 
 ous damage at Hampton Eoads, she was driven back by the Monitor's 
 two 11-inch guns, and never ventured on another trial. 
 
 There was a deal of wise discussion at the time about penetration 
 and wrought-iron shot, &c. ; but the simple and undisputed fact remained. 
 The Merrimac was obliged to endure the blockade of the Monitor, and 
 never dared to venture to the conflict 5 her commander preferred to sink 
 her, and did so. 
 
 At Mobile the few brief moments of opportunity were so aptly used 
 by the rapid fire of the 11-inch guns of the Chickasaw that the iron- 
 clad Tennessee yielded to their blows, when neither the tremendous 
 shocks of the steamers nor the sluggish fire of the 15-inch gun had 
 been able to accomplish the desired result. In the end they might have 
 done so, but in battle, time is just as essential to success as in other 
 things. Here it is notorious that the rapid and sustained fire of the 
 11- inch cannon of the Ironsides was more dreaded by the rebels than 
 the 15-inch guns of the monitors, and while she remained here attracted 
 the chief efforts of the rebels to blow her up. 
 
 If, then, so many important and undisputed facts have established the 
 endurance of these guns, while their origin, use, and association with 
 events have imparted to them a reputation so entirely naval, why pro- 
 pose any change in their manufacture ? 
 
 They have faithfully withstood every ordeal, and are now identified 
 with the fame of the navy in this great struggle of the country to main- 
 tain its very existence. 
 
 What public interest demands it, if all that has been proposed or 
 required in the use of the guns has been accomplished ? 
 
 Change of itself is not improvement, and it cannot in this instance 
 be made without additional expense to the treasury. 
 
 One cent per pound is seemingly no great expenditure, but in each 
 gun itself it amounts to one, two, or even four hundred dollars, and when 
 cannon must be made by hundreds the sum becomes important. 
 
 But the recommendation is not merely to substitute hollow castings 
 for solid, or to exercise a sound discretion at any time upon the subject, 
 for the 15-inch guns of the navy designed by myself are cast hollow, 
 
100 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 according to Major Eodman's plan of casting; the proposition is to use 
 no other mode of casting but Major Eodman's, and to bind the bureau 
 itself from using any other. 
 
 Why do this"? Why voluntarily impose a restraint when none is 
 needed? Is there any apprehension that the asserted superiority of the 
 hollow casting might suffer from competition 1 ? 
 
 No opinion is given in the documents of the bureau from Mr. Chaffee, 
 the manager of the Providence Works; I should have liked to know 
 his opinion ; and the letter of Seyfert and McManus is by no means a 
 testimonial to the merits of the hollow castings. 
 
 The paper of Mr. Parrott states many facts which are of interest, 
 though they seem to have escaped the pencilled selection of some care- 
 ful hand. I beg the particular attention of the Navy Department to 
 one of these remarks. 
 
 Mr. Parrot says : 
 
 I was particularly acquainted with the manufacture and trial of the navy 9 and 11-inch 
 Dahlgren guns, cast solid, and they had given more uniformly satisfactory results than the 
 hollow-cast columbiads of the old model, to which the experiments of Major Rodman were 
 for a long time confined. 
 
 It did not appear from the foregoing and other trials that the very great theoretical advan- 
 tages which might be hoped for in the hollow castings were particularly realized. (See 
 Rodman on Metals for Casting, &c., 1861, pp. 94, 96, for statements of these advantages.) 
 
 But a further experiment was made after the model of the 10-inch columbiad had been 
 changed, by rounding off the angular breech and giving increased thickness at the bottom 
 of the bore. In this instance both the solid and hollow-cast guns endured well, reaching 
 4,250 rounds each without bursting. 
 
 I think that what Mr. Parrot here states admits of neither question 
 nor qualification. Please to note that the solid-cast 11-inch gun, not 
 with any special care, but with no more than is usual in current manu- 
 facture of a large number, gave "more uniformly satisfactory results 
 than the hollow-cast columbiads of old model to which the experiments 
 of Major Kodman were for a long time confined." 
 
 Now note what Mr. Parrot says a little further on : 
 
 But a further experiment was made after the model of the 10-inch columbiad had been 
 changed by rounding off the angular breech, and giving increased thickness at the bottom 
 of the bore. In this instance both solid and hollow-cast guns endured well, reaching 4,250 
 rounds each without bursting. 
 
 The plain and direct conclusions from these statements are : 
 
 1st. That when Major Eodman's mode of hollow casting was applied 
 to the army columbiad of the old model my solid-cast 11-inch guns 
 gave more uniformly satisfactory results. 
 
 2d. And that when the model was changed there was obtained a very 
 striking advantage to Major Eodman's hollow casting. It went to 4,250 
 rounds. 
 
 This would have been a stubborn fact to overcome by itself, but it does 
 not stand by itself; for a gun of exactly the same improved model was cast 
 from the same furnace, the same iron, and cast solid, as the \\.-inch guns are 
 cast. That, too, endured just the same amount of firing as the hollow- 
 cast, nearly 4,250 rounds. 
 
 Well, from all this it follows: 
 
 1st. That hollow casting would not save a bad model. 
 
 2d. That when the bad model was changed to a better, the solid-cast 
 gun endured just a:u much as the hollow. 
 
 Now I desire that the department may be fully aware of what is 
 implied by this "rounding off the angular breech and giving increased 
 thickness to the bottom of the bore ; " and to do this I would ask that 
 three models may be made and placed before you, having the diameters 
 at the base ring equal in all three models. No. 1 shall be a 10-inch col- 
 
EXPERIMENTS ON HEAVY ORDNANCE. 101 
 
 ulnbiad of the old pattern, that even Major Bodman's hollow castings 
 would not save, and which he has abandoned. No. 2 shall be a 10-inch 
 columbiad of the pattern to which it was changed and which is now 
 used, having given so much endurance to the hollow and solid castings. 
 No. 3 shall be that of my 11-inch gun. 
 
 Let the eye then decide how far the model of the 11-inch gun departs 
 from that of the old columbiad or any previous model, naval or mili- 
 tary; and how marked the coincidence of the new army 10-inch and 15- 
 inch with the model of the 11-inch, the latter being rather longer ; but 
 in the disposition of the metal about the vital parts of the gun, how 
 close the resemblance. The appendage for elevating being a plate in one 
 gun and a cascabel in the other; but neither affects the principle of 
 construction that disposes the mass of metal about the bore. My guns 
 are chambered, and the army guns are not, which has no connection 
 with external model, but concerns the bore alone. 
 
 The eye cannot be misled by any special arguments developed in 
 lengthy technical formula and symbols entirely incomprehensible save 
 to the initiated few. To it the relative diameters at different parts, the 
 character of the curves that unite them, the absence of projections and 
 rings, produce forms as nearly identical as possible to vary at all. The 
 department has already the statements of Mr. Parrott that the mode of 
 hollow casting did not succeed with the old model, but that it had suc- 
 ceeded with a new model ; and I think it will appear from comparison of 
 the models just suggested that the model of the army 10-inch and 8-inch, 
 as well as the 15-inch, made by Major Rodman, is identical with the 
 models of my 9-inch and 11-inch guns. 
 
 This I submitted to the War Department some two years ago, and so 
 far all I gained by a plain statement has been some long arguments by 
 Major Eodman, in which he undertakes to show that the models are not 
 alike, as if any statement could possibly negative the plain evidence of 
 one's sight. So that the change to the hollow casting did not succeed 
 until a change of model was resorted to, and this was an adoption, in 
 effect, of the 11-inch model. 
 
 It is now attempted by the recommendation of the bureau to take from 
 me even the claim to the hard labor of years. Such a wrong as this I 
 feel assured will not be tolerated by the department. 
 
 It has caused me the greatest astonishment, coming as it does from 
 the naval Bureau of Ordnance, to which I might have looked for at least 
 fair play. 
 
 My absence and present duties might have plead for postponement at 
 least, no necessity being shown for such urgent action. But if the recom- 
 mendation must be made, why not a few weeks earlier than it was f I 
 was in Washington, and might have said a word in my own behalf. 
 Why defer until some three weeks after I left, a proposition involving so 
 much to myself, and then urge it upon the department, leaving me after- 
 wards in utter ignorance of what was going on, until the department 
 insists on knowing what I have to say I 
 
 Nothing but the consideration of the Navy Department averted the 
 decision. With a wise and sound discretion it refused to act hastily, and 
 until I had been heard. 
 
 I cannot admit that we yet know all that is needed to a full decision 
 as to the mode of casting. If hollow casting is better for any size of 
 guns, why cool it with water 1 Will not the old mode of casting hollow, 
 as practiced a century, answer ? Who can speak of trials made with 
 American material, such as now used, and American experience ? 
 
 Mr. Chaffee had the boldness to cast a 13-inch gun solid, and it endured 
 172 firings ; this was considered a failure. 
 
102 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 When the largest of these hollow-cast columbiads gave way with per- 
 haps no better endurance, was that considered a failure ? Mr. Chaffee 
 had never cast so large a gun ; he had never melted and cooled the iron 
 he used in such great masses ; if he reached the result he did at the first 
 trial, what might be expected by further experience f 
 
 My own impression is that this result was, under the circumstances, 
 highly favorable. 
 
 In conclusion, I hope that I have been able to satisfy the department 
 that there is every propriety in my submitting an earnest protest against 
 the recommendations of the Bureau of Ordnance : 
 
 1. It is needless, because the 9-inch and 11-inch guns have done all 
 that has or should be required of them without failing in any one instance. 
 
 2. It is an additional expense to the government without any advantage. 
 
 3. It is unjust to the hard and constant labor which I have given to 
 the subject, and to the benefit which the navy has derived from these 
 labors. 
 
 4. It is forbidden by professional regard for ordnance naval in its 
 origin, naval in its use, and naval in its association with great results. 
 
 I will only add my earnest request that the department will give an 
 order to the Bureau of Ordnance that no change whatever shall be made 
 in the model or details of my 9-inch and 11-inch guns, and that they 
 shall continue to be cast and finished just as they have been that is, 
 solid ; and that no change shall be made in the model or details of my 
 new 130-pounder (10-inch) and 13-inch guns. 
 
 I believe it is supposed by some that considerable pecuniary advantage 
 results to me from these guns. I have only to say that I never derived 
 a cent from them, nor asked for it. 
 I have the honor to be, very respectfully, your obedient servant. 
 
 J. A. DAHLGREN, 
 
 Rear-Admiral, Contfdg South Atlantic Blockading Squadron. 
 Hon. GIDEON WELLES, 
 
 Secretary of the Navy. 
 
 NOTE B. 
 [From the " Ordnance Instructions," United States navy, 1866, page 102, part /.] 
 
 Owing to the recent accidents which have taken place with these guns the ISO-pounder has 
 been withdrawn from service, and the charge of the 100-pounders provisionally reduced to 8 
 pounds of rifle powder, and the short shell of 80 pounds only is to be used. 
 
 JANUARY 29, 1869. 
 NORMAN WIARD recalled. 
 
 By the CHAIRMAN : 
 
 1. Question. What are the most important qualities of the metals fitting 
 them to be the material from which guns are to be made ? 
 
 Answer. Tensile strength, i. e., ability to resist ultimate pressure or 
 ability to resist breaking apart against the extending strain. Permanent 
 elasticity is next in importance, which is, in fact, the ability to recover 
 the original form and dimensions after the distorting force has ceased to 
 act. Incompressibility is another important quality, involving hardness 
 to resist penetration or abrasion. Ductility is a quality not desired in 
 gun metals, as it is seldom accompanied by elasticity. The qualities of 
 metals as conductors or non-conductors of heat should be considered, as 
 
EXPERIMENTS ON HEAVY ORDNANCE. 103 
 
 the metal for large guns which will conduct the heat slowest from the 
 surface of the bore outward when being fired would be most unequally 
 heated, other conditions being equal. 
 
 2. Q. What direct forces act upon the bore of the gun, having the tend- 
 ency to deteriorate it or destroy it ? 
 
 A. The elastic force resulting from the combustion of gunpowder 
 should be divided and considered in both of its forms, namely : pressure 
 that is inert without motion, but which is exerted in all directions 
 equally, requiring a definite strength to resist its performance of work, 
 and projectile force, or vis viva, a quality of force resulting from the ele- 
 ments of pressure and velocity, pressure and distance, or pressure and 
 time of action while in motion. 
 
 3. Q. When a chamber is filled with gunpowder and the powder is 
 ignited, which of these forces act upon its surface ? 
 
 A. If a chamber be filled with grains of powder, and each grain be 
 ignited simultaneously, the gas resulting from combustion would flow 
 radially in all directions from each grain as a centre ; the currents meet- 
 ing half way between contiguous grains would expend nearly all their pro- 
 jectile force and motion upon each other, resulting in a pressure against the 
 walls of the chamber, but slightly greater upon each square inch of the sur- 
 face, than would result in the same chamber if the grains had been inserted 
 one at a time in succession and ignited, with the gas confined until the 
 same quantity of powder had been burned. If the chamber were spherical 
 and only half filled with powder grains, upon the ignition as before, part 
 of the powder and gases would be projected across the vacant space in 
 such various directions that a large part of the projectile force would be 
 expended by the diverging, converging, and reverberating currents, upon 
 each other. The effect upon the walls of the chamber on the unfilled side 
 would be, however, greater than in the previous case referred to with the 
 chamber full, though depending principally upon the rapidity of com- 
 bustion. If the chamber contained the proper quantity of water to be 
 evaporated into steam, and which created the same ultimate pressure in 
 the chamber, to be generated by slowly heating the water, it is obvious 
 the rate of its projectile force against the walls of the chamber would 
 but slightly exceed the forces of ultimate pressure. If the Kodman 
 instrument. Plates VIII and IX, relied upon by the ordnance corps for 
 the determination of the pressure of powder in guns, should be inserted 
 in the side of the chamber while the pressure of the steam was gradually 
 evolved, the cut in the copper specimen would have the same depth as 
 any other cut in any other specimen made by the application of a weight 
 equal to the pressure, in pounds, of the steam against the piston of the 
 instrument. But if the Eodman instrument should be applied to the 
 chamber upon the outer end of a tube seven inches in length, having a 
 stop-valve closed while the steam was being generated to the pressure 
 of 5,000 pounds to the square inch, when the valve was opened the steam 
 would flow along the tube with such velocity as to strike the piston of 
 the instrument with a projectile force, which would cause a penetration 
 of the copper specimen so deep as to represent a force of 15,850 pounds. 
 If the length of the tube should be increased from seven inches to nine 
 inches, the projectile force would be equal to a pressure on the piston of 
 21,100 pounds, and with 11-inch length of tube, the pressure would be 
 equal to 27,800 pounds upon the square inch. These statements and 
 figures are founded upon the experiments of Eodman, as shown on page 
 197 of his book, (see Appendix D, miscellaneous extracts,) the result of 
 the firing guns, each having a different thickness of wall, namely, a 7 inch 
 gun with a wall about seven inches thick at the front of the cartridge ; a 
 
104 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 9-inch gun with a 9-inch wall, and an 11-inch gun with an 11-inch wall. 
 If it was pressure of the powder in this case which caused the velocity 
 to be given to the projectile, it is most remarkable that the velocity of 
 the shots for a mean of 10 fires from the 7-inch gun, in which the powder 
 exerted a mean pressure, according to the indications of the instrument, 
 of 12,675 pounds to the inch, should be so nearly the same as the velocity 
 of the projectile from the 11-inch gun, in which the instrument shows 
 the mean pressure to have been 36,224 pounds to the square inch, or 
 nearly three times to force "behind an equal column of metal.'*' (The 
 table of the results referred to is shown, Appendix D.) 
 
 4. Q. Then you have the opinion that the Rodman instrument only 
 shows the projectile force of the powder, and not its pressure ? 
 
 A. The deductions drawn by Rodman in relation to the pressure exerted 
 by the powder upon the surface of the bore of the guns are very lame 
 conclusions, yet they have been taken as indicating a proper model for 
 guns to give "the required strength at the different points of their length, 
 and as confirming the fallacious conclusions of the ordnance corps, 
 founded upon the experiments of Colonel Bomford many years ago, 
 having for their object the determination of the pressure at the different 
 parts of the length of the bore. Colonel Benton says of these experi- 
 ments: "About 1845, Colonel Bomford devised a plan for determining 
 the pressure at various points of the bore by conducting experiments that 
 essentially consisted in boring a series of small holes through the side of 
 the guns at right angles to its axis, the first hole being placed at the seat 
 of the charges, and the others at intervals of one calibre ; a steel ball was 
 projected from each hole in succession by the force of the charge acting 
 through it, and the pressure at the various points was deduced from the 
 velocities communicated to the balls.'" This, and the common use of the 
 Rodman instrument in all late experiments by the ordnance corps, 
 shows that it is only the projectile forces of the powder which has been 
 considered by them from 1845 to the present time, and upon these falla- 
 cious theories the models of our guns have been determined and their 
 strength fixed. 
 
 5. Q. What is the difference between the projectile force and the 
 pressure of the powder, and has one a fixed and continuous proportion 
 to the other ? 
 
 A. The projectile force of the powder is the force equal to that which 
 would be developed or exhibited in stopping the projectile. The pressure 
 is that force which gives it motion in the gun, and it can be seen that if 
 such a force as that acting upon the projectile should act against the sur- 
 face of the bore in the gun, no material could be found from which guns 
 could be made which would not either enlarge the bore or burst as a gun, 
 unless it were from material which, if formed into a plate and fixed upon 
 the side of a ship as armor, would resist the impact of a shot from a gun 
 without any indentation whatever. When a wrought-iron shot is fired 
 from a gun at a plate which it does not penetrate to any considerable 
 depth, the shot is flattened by the impact. If the pressure of the powder 
 were not less than the projectile force, the shot would be invariably flat- 
 tened to the same extent in the gun, which, however, is not the case. I 
 have frequently experimented with an air-gun of one-fourth of an inch in 
 diameter of bore. With a pressure of 750 pounds of air to the square 
 inch in the receiver, the bullet is projected with force enough to pass 
 through one inch thickness of hard wood. After charging the gun with 
 that pressure, I have discharged a bullet from it and penetrated that 
 thickness of wood ; then after inserting another bullet, have restrained 
 it from being ejected from the barrel by inserting a steel ramrod down 
 
EXPERIMENTS ON HEAVY ORDNANCE. 105 
 
 against the bullet by the pressure which I could exert with my hand, 
 grasping the ramrod where it protruded from the muzzle of the gun ; 
 upon removing the ramrod the same bullet previously held in the gun 
 was discharged and passed through the wood target. It is obvious that 
 I could not have forced the ramrod through one inch of hard wood by 
 any pressure that I exert by my hand under such circumstances. In fact, 
 I found that I could scarcely make a perceptible indentation in the wood 
 by a pressure on the ramrod equal to that which I had exerted while 
 restraining the bullet in the gun. 
 
 6. Q. Are the indicated pressures shown by the Eodman instrument 
 uniform under like circumstances 9 
 
 A. They are not ; on many occasions, with equal charge of powder 
 and equal weight of projectile in the same gun, the results have been 
 widely different they are quite as incongruous as would be the penetra- 
 tion of a shot from the same gun projected against iron armor, if the 
 shot should sometimes strike fair, and at various other times ricochet once, 
 or ofteiier, from intervening ground between the gun and target or meet 
 obstructions to its flight previous to hitting the plate. 
 
 7. Q. What is the cause of the uncertainty of the instrument? 
 
 A. The currents of gas projected against the piston of the instrument 
 are obstructed sometimes by the intervening grains of the unburnt pow- 
 der. They may be reflected or diverted from the straight line of direction, 
 thus expending their projectile force, or part of it, against other surfaces, 
 in which case of course the instrument could not record the full projectile 
 force. 
 
 8. Q. Is it only the projectile force of the gases of powder which causes 
 the penetration of the specimen with the Eodman instrument ? 
 
 A. No ; there is also the projectile force of the piston and moving parts 
 of the instrument itself, (see figure 2, plate IX,) which adds greatly to the 
 force as it is recorded, so that under no circumstances whatever could 
 the instrument fail to show a force much greater than the direct pressure 
 of the powder as exerted to enlarge the bore or burst the gun. So called 
 pressures have been indicated by the instrument on the 15-inch gun 
 with 55 pounds of powder, as low as 10,000 pounds to the square inch, 
 and indications from 11,000 to 13,000 pounds are quite common in the 
 reports ; it is quite impossible, considering the momentum of the piston 
 and moving parts of the instrument, but that these lowest pressures are 
 greater than the real pressure exerted by the gases of the powder on the 
 gun under any circumstances. In one report I find a pressure as recorded 
 of 13,000 pounds giving an initial velocity to the shot of 1,441 feet per 
 second, and on another page of the same report another pressure of 98,000 
 pounds, in the same gun, giving only a velocity of 1,240 feet per second 
 with an equal charge. 
 
 9. Q. Is it possible to avoid having the projectile force of the gases of 
 the powder act upon the surface of the bore in the gun ? 
 
 A. It is only necessary, in order to prevent the projectile force acting 
 to an injurious extent, that the chamber should be full, whether the 
 powder be coarse or fine, or whether it burns quick or slow ; the ultimate 
 pressure would be nearly the same, if the powder is composed of the same 
 elements equally incorporated. The projectile force with which the 
 gases of the powder expand, if unrestrained even for a short length of 
 time, is much greater for quick than for slow-burning powder. If the 
 projectile should not be down against the cartridge, although the impact 
 of the projectile force of the gases against the rear end of the shot would 
 be greater than the pressure of the powder, the shot would not have so 
 high a velocity communicated to it, because the time of the action of the 
 
106 EXPERIMENTS ON HEAVY OKDNANCE. 
 
 force against the shot would be less. Therefore if a shot should be 
 placed just at the muzzle of the gun, the force of the impact of the gases 
 against the rear end of the shot would be maximum, and the velocity 
 communicated to the shot would be a minimum. 
 
 10. Q. And, therefore, the highest velocity is attained from a gun by 
 having the shot down against the cartridge, is it ? 
 
 A. When the charge is rammed or forced down against the powder 
 cartridge in such a manner as to close up all the grains of powder into 
 close contact with each other, and with the surface of the bore or chamber 
 of the gun, the velocity of the projectile is greatest, and the strain upon 
 the gun least possible from a like charge in a like gun. 
 
 11. Q. Did a gun ever burst from the premature bursting of a shell in 
 the bore ? 
 
 A. If a shell should be burst in the muzzle of a 15-inch gun containing 
 a charge such as would nearly burst the gun in that part, but not quite, 
 the force with which the fragments of the shell would be projected against 
 the surface of the bore would cause numerous and deep indentations in 
 the metal of the gun ; the cause of such indentations could not be easily 
 misunderstood or overlooked, especially if we should be informed or 
 believed a loaded shell lying in that part of the bore had been exploded 
 while at rest. The part of the shell forming its largest diameter would 
 be projected against the surface of the bore violently, and it would surely 
 leave its mark if the force of the explosion reached nearly to the force 
 necessary to rupture the gun. Yet I have examined 23 large guns which 
 have burst at the muzzle : three of them were Dahlgren 11-inch guns ; 
 one Dahlgren 8-inch gun ; two 10-inch; six 15-inch; two army 42 pound- 
 ers, rifled ; one 32-pounder, rifled ; and eight large Parrott guns. I was 
 informed, either by the persons who were present at the time of the 
 accident, or by the ordnance department, that many of the accidents 
 were attributed to the premature explosion of the shells in the bore; I 
 therefore examined them carefully, and found not a single case exhibiting 
 any enlargement of the bore whatever, and not the slightest indentation. 
 It is quite impossible that so many cases of rupture could have occurred, 
 or even that one could have happened from the premature discharge or 
 explosion of the shells in the bore, without permanent enlargement of the 
 bore or indentation, which would be apparent to the practiced eye even 
 without the aid of instruments. 
 
 12. Q. If it is not the bursting of the shells in the bore, how do you 
 account for the bursting of the guns at the muzzle I 
 
 A. There is a correlation and conservation of heat and force. Heat and 
 ability to perform work are exact equivalents. Force, while being 
 resolved into motion, if restrained, is changed into heat ; if unrestrained, 
 into work performed. So, if a man of the weight of 150 pounds climb a 
 ladder to the interior of the dome of the Capitol, 100 feet high, his body 
 becomes charged during his ascent with the ability to perform a definite 
 amount of foot-pounds of work in descending again exactly 15,000. If 
 he should grasp a rope which passed freely over a pulley and was fixed 
 at its opposite end to a weight of 149 pounds down at the floor, by the 
 descent of his body the weight might be raised to the same height from 
 which he descended. To raise such a weight of 149 pounds to such a 
 height 14,900 foot-pounds of work would be performed, 100 foot-pounds 
 less than the descending weight would be capable of performing. The 
 difference of 100 foot-pounds being expended in friction would be 
 simultaneously resolved into heat. Suppose the rope were fixed so as not 
 to flow over the pulley, but was grasped in the hands with such compara- 
 tive tightness as to permit slipping slowly downwards ; so much heat 
 
EXPERIMENTS ON HEAVY ORDNANCE. 107 
 
 would be evolved by the friction as to burn the flesh off the bones of the 
 hand. Thus, if the projectile is restrained in the gun by rubbing too 
 tightly along the bore, the friction might create heat enough to weld the 
 projectile to the gun. If one-half its projectile force should be restrained, 
 one-half of its ability to perform work would be expended in heating the 
 surface of the bore almost instantaneously ; this heat, of course, would 
 be communicated to the interior in advance of heating the outside of 
 the tube ; the force of the longitudinal and radial expansion would be 
 sufficient to burst the gun. 
 
 13. Q. By the conservation of force cannot you account for the burst- 
 ing of guns elsewhere than at the muzzle ! 
 
 A. In a report made by Captain Thomas Edson on (the bursting of) 
 the 13-inch Rodman gun at Fort Monroe arsenal during the firing from 
 it, July 23 and 27, 1864, three rounds were fired on the 27th with 55 pounds 
 of Dupont's ]STo. 5 powder and a solid shot of 283 pounds; the Eodman 
 instrument gave a pressure for the three rounds of 152,000, 170,000, and 
 180,000 pounds, respectively: for the first two rounds 1,505 feet initial 
 velocity; for the third round 1,800 feet. On the 23d two rounds were 
 fired with the same kind of charge. At the first round the so-called 
 pressure was 200,000 pounds to the square inch ; at the second round 
 160,000 pounds, and the initial velocity was only 1,188 feet per second. 
 The rate of the velocity of these rounds, and the others, with the pressures 
 shown, should have been 1,600 feet per second ; about one-fourth of the 
 force of the charge was expended therefore in some other manner than in 
 giving velocity to the shot. Let us suppose it to have been expended in 
 friction along the bore ; resolve it into foot-pounds, according to this new 
 light, " the conservation of force," and see what the result is in plain figures. 
 The shot 13 inches in diameter has 132 square inches area, against which 
 the expansive force of the powder acts in ejecting it from the gun. 
 This area multiplied by the pressure in pounds to the square inch, 
 132x160,000 = 21,120,000 pounds of instant pressure against the shot. 
 In order to simplify the calculation I will assume that this full pressure 
 acts against the shot while it is moving along the bore, a distance of five 
 feet. Then 21,120,000x5 = 105,600,000 foot-pounds. One quarter of 
 these foot-pounds would be equal to raising 26,400,000 pounds one foot 
 high, one pound 26,400,000 feet high, or 2,534,400,000 pounds one- 
 eighth of a foot high; all these amounts of work being equivalents. All 
 this intense force might be exerted in as practical a manner to burst a 
 gun by unequal expansion, which would result from heating the surface 
 of the bore in advance of heating the outside, as the same force could be 
 directed by the best intelligence in any other manner; therefore it 
 becomes necessary to devise guns and projectiles, if possible, which shall 
 not in any contingency have any friction between the projectile and the 
 surface of the bore. 
 
 14. Q. Is the pressure upon the square inch of surface for a small 
 charge less upon the square inch of surface of the chamber than for a 
 large charge"? 
 
 A. There cannot be any materially greater force to act upon the 
 chamber of a gun, resulting from a large charge of powder, than from a 
 small one. A cubic inch of powder fired in a chamber which it fills will 
 exert the same pressure upon the square inch of surface of the chamber 
 as would be exerted upon a square inch of surface of a chamber with a 
 cubic foot of capacity if also filled with powder. 
 
 15. Q. Has the friction of the gases or the grains of powder the effect 
 to heat the interior of a gun! 
 
 A. The friction of unburnt grains of powder sliding along the surface 
 
108 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 of the bore would of course have a tendency to heat the interior of the 
 gun more rapidly than the exterior ; but there is a greater force than 
 this, which I discovered in the following manner also resulting from 
 friction: In firing a 12-pounder rifled gun in 1861, I found that 1 
 pound of powder gave a higher velocity than any larger charge of pow- 
 der. After proving the fact by firing the gun for range, a few shots 
 were projected into a sand butt with three-pound charges, and upon 
 recovering the projectile I found that part of the powder charge adhered 
 to the rear of the shot, pressed into a cake, apparently as hard as soap- 
 stone, which it resembled. Upon this I concluded that the loss of velocity 
 was due to the fact that not more than one and a-half pounds of powder 
 could be burned in a gun of that calibre, but did not notice at this time 
 that the velocity was much less with three pounds than with a pound 
 and a-half. At a later time I had occasion to fire a breech-loading gun 
 of 12 pounds calibre, in which the chamber was larger than the bore, 
 and having inserted the cartridge, accidentally, previous to the insertion 
 of the projectile, I endeavored to force the cartridge through towards 
 the muzzle, and finding it did not move easily, I applied increased force, 
 using a block of wood with the blows of the sledge to drive it through, 
 but in vain. I then endeavored to drive it back by the same means, 
 but could not move it en masse either way. Upon digging out the pow- 
 der with a pointed instrument of wood it was found in a hard cake 
 resembling that which adhered to the shot in the previous experiment 
 mentioned. From this I drew the conclusion that the retardation of 
 the projectile resulted from excessive friction which attended the slip- 
 ping of the unburned powder along the bore jammed behind the shot as 
 it would be when the cartridge of an excessive charge was ignited at 
 the rear end of the chamber. 
 
 16. Q. How can this be prevented ? 
 
 A. When large charges are used it may be almost entirely prevented 
 by igniting the cartridge at the front end ; so the projectile only will 
 have to be moved along the bore while the unburnt powder is forced 
 back- into the chamber. 
 
 17. Q. Do you know any other injurious forces which are exerted to 
 burst guns which may be so controlled as not to have injurious effect ? 
 
 A. I do. Guns are usually mounted so as to recoil backwards in a 
 plane different from the plane of the bore when the gun is elevated. 
 An improvement in the manner of mounting in this respect is needed: 
 I exhibit on Plate XIV a plan which I have designed for this purpose. 
 A gun should recoil backwards while the shot is being ejected exactly 
 in the opposite direction to that in which the shot is moving; then 
 there would be no greater pressure upon the bottom of the bore from 
 the projectile than that due to the weight of the shot when at rest. 
 
 The effect of the gun in recoiling in any other direction is to divert 
 the shot from its aim, and results in greatly increased friction along the 
 bottom of the bore detracting from the range of the projectile and exert- 
 ing forces which have a tendency to break off the muzzle of the gun or 
 burst it at the muzzle. When a gun is burst at the muzzle by any of 
 these forces in combination or alone, no mark is left on the bore to 
 indicate the cause of the accident, which is therefore, as I have saidbefore, 
 erroneously attributed to the premature bursting of the shells in the 
 bore. If it happen that the gun bursts when a solid shot is fired from 
 it, or at a round when a shell is fired, which does not prematurely burst, 
 the bursting is attributed all the same, and the premature bursting of 
 some shell previously fired is referred to as the cause of the accident. 
 Thus the whole subject is shrouded in impenetrable mystery and another 
 a incongruous result" added to the already too long list. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 109 
 
 18. Q. What is the cause of the enlargment of the bore of a gun at 
 the seat of the shot so frequently referred to in the reports of the ord- 
 nance department. 
 
 A. When the pressure of the powder acts upon the rear of the pro- 
 jectile in a gun, and before its front has motion imparted to it, the rear 
 has moved forward; thus the axis which coincides with the longest 
 axis of the bore of the gun is reduced in length and the diameter of the 
 projectile is increased in all radial directions. While this occurs, the 
 projectile being only in contact with the bottom of the bore, it must 
 either penetrate the metal of the gun at the place of contact or the pro- 
 jectile must be lifted up bodily. Usually the result is a little of both ; as the 
 projectile receives its forward impetus along the bore, it therefore re- 
 bounds; from its elasticity and the elasticity of the metal of the gun, it 
 jumps upward and strikes the top of the bore a little forward of its first 
 position ; glancing then downwards, it rebounds again from the bottom, 
 and so goes on balloting from top to bottom until it escapes from the 
 muzzle. This balloting has injurious effects upon the bore of the gun; 
 it results in increased friction and consequently in increased temper- 
 ature, which retards the velocity of the shot and destroys the paral- 
 lelism of the bore and of the gun, inasmuch as it penetrates it or injures 
 it irregularly ; of course guns are sometimes enlarged by the direct pres- 
 sure of the powder arrested by tension. 
 
 19. Q. Cannot this be prevented? 
 
 A. It can be when due to ballotting or upsetting of the projectile by 
 supporting the projectile centrally in the gun with equidistant windage 
 all around, previous to igniting the charge. 
 
 20. Q. Is there any direct communication of heat from the gases of 
 the powder to the surface of the bore ? 
 
 A. The heat of the gases of powder except by friction, or by the aid 
 of currents, is communicated slightly or slowly. The heat of steam is 
 communicated rapidly to any colder surface with which it is in contact ; 
 because, as the heat is expended below 180, a vacuum, or partial vacuum, 
 is formed. The current is thereby forced to flow with inconceivable rap- 
 idity to the surface, receiving the heat, whereby the heat of the other 
 steam, previously at a distance from the cooling surface, is communicated. 
 In this steam is quite different from other gases containing heat, such as 
 air, or the gases resulting from the combustion of the gunpowder, all 
 of them being non-conductors, and all of them having an extremely low 
 specific heat. Only the gas which is in contact with the surface of the 
 bore of a gun imparts its temperature to it ; thus it is thereafter inter- 
 posed as a non-conductor between the surface and the hotter gas at a 
 distance ; which is thus prevented from giving its heat to the surface. 
 With that part of the gas which is flowing through the vent or passing by 
 the windage of the shot itself it is different. The large quantity pre- 
 sented to the surface in quick succession in such a case communicates 
 its heat, and immediately it passes away, giving place to other quantities. 
 In this manner a larger proportion of heat is communicated to the vent 
 than to another equal surface to which the gas is exposed in a gun : first, 
 because the fire is lighted at the vent, and the hot gas flows longer over 
 that part ; and second, because the vent passage is least liable to obstruc- 
 tion. In the case of the rifle projectile the windage is usually entirely 
 obstructed, and in smooth-bore guns unburnt powder grains, or the cart- 
 ridge bag may be forced forward to stop the windage, and the passage 
 of the heated gas past the shot. After the bore becomes worn at the 
 seat of the shot, and the vent is injured, more heat is communicated than 
 while the gun is new. More heat would always be communicated to the 
 
110 EXPERIMENTS ON HEAVY ORDNANCE 
 
 vent and the bore of the gun, by the passage of the hot gas, after they 
 had become worn and rough from the slipping of the gases over the 
 rough surface, causing increased friction and as a tendency to restrain the 
 expansion of the gas in motion, as well as the motion of the projectile, 
 causes force to be changed into heat, by friction which may act injuriously 
 upon the gun, by unequally heating it and straining it through unequal 
 expansion. 
 
 21. Q. Has no way been devised to prevent the heating of the gun 
 metal about the vent ? 
 
 A. A variety of the plans may be adopted to close the vent against 
 the escape of the gas ; or the charge may be ignited without any vent, 
 and thus a serious cause of injury to guns of large calibre may be 
 obviated. 
 
 22. Q. Then is there any manner which may be adopted to prevent 
 the communication of heat along the surface of the bore? 
 
 A. The unequal expansion which results from the direct communication 
 of the heat of the gases of powder, or the heat evolved from friction of 
 the gas or of unburnt grains of powder, or powder jammed against the 
 projectile, or rubbing or balloting of the projectile against the surface 
 of the bore, is the principal cause of bursting of guns. The injurious 
 effects may be prevented by making the gun elastic between the inner 
 metal and the reinforce, according to a plan which I have devised, Plates 
 XIII and XLV, and present herewith. 
 
 23. Q. What advantages does this gun possess over the Parrott gun of 
 the same calibre, cast hollow, in your estimation ? 
 
 A. It can be made to have a finer texture or molecular construction of 
 the metal (see Plate VII) without injurious tensions, greatly increased 
 strength to resist the forces acting upon it as a gun, from the increased 
 rate of decarbonization admissible in its metal, which will increase its 
 tenacity ; it will also increase the permanent elasticity of the metal, per 
 5e, and in addition to that, from its form or model it will have a wide 
 range of elasticity to permit the radial and longitudinal expansion which 
 results from heating the gun from the interior in any or all of the 
 various ways I have alluded to. (See Plates XIII and XIV.) 
 It can be made from the iron of old guns ; and it has been heretofore 
 deemed impossible to re-cast the iron of old guns into new ones, as the 
 strength and density are increased thereby, as can be learned by refer- 
 ring to Rodman's book, (Appendix D,) which shows the strongest 
 metal does not make the strongest gun, although the reason for that 
 seeming paradox is not very plainly shown. It is undoubtedly because 
 of the increased rate of decarbonization which results from remelting 
 cast iron, keeping it longer in the melted state, or in fusion, giving 
 greater tensile strength and the increased density which accompanies 
 higher tensile strength, resulting from further decarbonization of cast 
 iron. The higher the density, the greater the force with which the ex- 
 pansion of the metal will be accompanied when heated ; and the greater 
 the force of unequal expansion when unequally heated, as well as the 
 greater tensions which will result from unequal cooling, is an effect of 
 remelting or longer time in fusion. This gun (Plate XIV) can be made 
 cheaper than the Parrott gun because no wrought iron is used in its con- 
 struction, and no iron is wasted by turning off the gun along the chase; 
 it will not be weakened or unequally heated by the waste of gas through 
 the vent, because it has no vent, the charge being ignited at the front 
 end of the cartridge by a revolving pin inserted through the cascable 
 within a copper tube. Many of these details are not shown in the draw- 
 ings. The friction of unburned or jammed powder along the bore is 
 
EXPERIMENTS ON HEAVY ORDNANCE. Ill 
 
 also avoided by lighting the cartridge at the front end ; and the friction 
 of the projectile against the surface of the bore is to be avoided by hav- 
 ing no contact, except in the two rifled grooves, which are to be kept 
 smooth and polished ; and the projectile is to be supported centrally in 
 the gun, bearing only upon two gibs of brass, to slide in the grooves as 
 freely as the cross head on a steam-engine piston-rod slides upon the 
 guides, which will result favorably in giving increased velocity to the 
 shot. The gun having but two grooves, (see details, Plate XIII,) neither 
 of which cross the bottom or top of the bore, it remains essentially a 
 smooth-bore gun for spherical projectiles, and is also available as a rifle. 
 When spherical shot or shell are to be used the projectile is to be sup- 
 ported centrally in the bore by three pins of brass projecting from its 
 bottom, to rest on the bottom of the bore like the legs of a stool, thus 
 preventing rubbing contact. 
 
 24. Q. Why could not the round projectile have the rifle motion im- 
 parted to it ? 
 
 A. It could. I forgot to mention that instead of the pins to support 
 the projectile centrally in the bore it might be provided with the gibs 
 to slide in the grooves. No more windage should then be given to the 
 shot than experience taught would be equal to the radial enlargement 
 under the pressure of the gases of powder ; improved accuracy and 
 range would result. The rotary motion given to the round projectile 
 would not render its ricochet uncertain 5 and the gibs might be so 
 adjusted as to fly off after the projectile had left the gun. Sporting rifles 
 are extensively used in the west with round bullets. 
 
 25. Q. Would not the unequal heating you have described, resulting 
 from the friction or direct heat of the gas, affect the interior tube of this 
 gun injuriously, or burs tit? 
 
 A. Oh, no, sir ! because a tube having no more than four inches of 
 thickness may be melted by heat communicated entirely to the interior 
 surface without bursting it. Field and siege guns do not burst, however 
 rapidly they are fired, if the wall of metal surrounding the bore is no 
 more than four inches thick ; it is only the metal of the reinforce, which 
 surrounds that thickness in larger guns, which is ruptured by unequal 
 expansion. 
 
 26. Q. Then why make any gun of greater thickness? 
 
 A. Simply because if the calibre is large it requires the strength of a 
 thicker Avail to resist the direct pressure of the powder. There is no 
 trouble attends making small guns ; and it is to be noticed that all gun- 
 makers have achieved their reputation on small guns. Sir William. 
 Armstrong made a small gun first, and it exhibited remarkable qualities 
 of accuracy and range. His field guns afterwards were highly approved. 
 He only met serious difficulties when large calibres, involving more than 
 four inches thickness of wall, were attempted. So also with the guns 
 produced by Mr. Parrott ; first 10-pounders, then 20-pounders, and 30- 
 pounders, all of which were successful guns. One of the 30-pounders 
 endured 4,600 rounds, on Morris island ; and although the 100-pounder 
 endured the proof of slow firing, at the foundry, showing that the 
 strength was sufficient to withstand the pressure of the powder, the first 
 one fired rapidly, in service, viz., the one on the steamer Naugatuck, in 
 the attack on Fort Darling, was burst ; and afterwards all of that class 
 of guns of large calibre, and the necessary thick walls, whenever sub- 
 jected to conditions which heated them unequally, burst likewise. 
 
 27. Q. Then why will not the direct pressure of the powder burst the 
 gun you propose, which has a thin tube of iron about the bore ? 
 
 A. Because a pressure nearly equal to the strength of the reinforce 
 
112 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 is exerted on the outside of the tube, by contracting the band upon the 
 edge of the webs which surrounds the tube; each web being a beam to 
 support the tube forward and behind the band, and if this pressure exerted 
 by the band equals the pressure the powder would exert from the inside 
 of the tube, there is no tendency to break it or enlarge it. The pressure 
 of the reinforce is exerted upon this thin tube as if springs were inter- 
 posed between it and the band. (See cross- section, Plate XIV.) The 
 pressure of the powder is not sufficient to bend the springs further, 
 although the greater force, resulting from heating the interior to expand 
 the tube, may be sufficient to bend them to a slightly greater extent than 
 they would be bent by the tension of the reinforce. There is such a 
 wide difference or margin between the " instant pressure 77 of the force 
 which results from the pressure of the powder, and that of the force 
 which results from expansion of the metal by heat, that it is quite prac- 
 ticable to interpose these springs between the interior and exterior of 
 the gun, and thereby restrain the pressure of the powder, and permit 
 the expansion by heat, which cannot be restrained. (See cross-section 
 of details, Plate XIII. ^ 
 
 27. Q. But the tube will expand lengthwise, also ; how can you pro- 
 vide for that? 
 
 A. By the peculiar form of the springs, or webs ; they are made to have 
 elasticity for the lengthwise as well as the radial expansion. (See ele- 
 vation, 200-pounder rifle, Plates XIII and XIV.) 
 
 28. Q. Could this gun be made of wrought iron? 
 
 A. It could very well ; but the ductility of wrought iron is a very 
 objectionable quality for guns. Wrought iron will stretch permanently 
 under a force which, if exerted upon equal ultimate strength of cast iron, 
 would only enlarge it within its permanent elasticity, and it would 
 recover after the force was removed, and wrought iron would not. 
 Wrought iron is also softer, and would be more easily abraded and 
 scratched in the bore ; it is more rapidly wasted by rusting and more 
 subject to the action of acids of powder than cast iron or steel ; the 
 carbon protects the latter from the rapid action of oxygen or acids ; 
 carbon having a stronger affinity for oxygen than iron has, the oxygen 
 unites with the carbon first. We owe it to this fact that we can make 
 wrought iron from cast iron, to do which only requires the extraction of 
 the carbon from the cast iron or steel. Wrought iron has the other 
 objectionable quality as a material for guns, viz: that it cannot be made 
 homogeneous. It is not practicable to melt and flow it in the liquid 
 state into the required form of uniform structure as we can with cast 
 iron ; it must be welded, and the welds are places of weakness. The 
 cost of a wrought-iron gun is about four times as great as the cost of a 
 cast-iron gun. 
 
 29. Q. I see in Holley's book (Fig. 160) an account of fissures which 
 occurred in a large mass of wrought iron, which were attributed to some 
 other cause than bad welding. Is it common to find defects in that kind 
 of iron? 
 
 A. Fissures of that kind (Plate X) only happen when the mass is large, 
 and are caused by " the contraction from the centre towards the circum- 
 ference as the mass cools." They are, in fact, an effect of unequal con- 
 traction resulting from unequal cooling, and resemble the cavities found 
 in the centre of large masses of cast iron half-way between the cooling 
 surfaces, if exposed to an equal rate of cooling from all the surfaces. I 
 have here a piece of iron, broken from the centre of a large mass, which 
 you will notice is of a very coarse structure, (Fig. 4, Plate VII;) the faces 
 of the crystals are one-fourth of an inch across; and another piece cast 
 
EXPERIMENTS ON HEAVY ORDNANCE. 113 
 
 at the same time from the same lot of melted iron of a smaller diam- 
 eter. The molecular structure of the iron of the thin part (Fig. 1, 
 Plate VII) is entirely different 5 it is as fine grained as cast steel. These 
 peculiarities of structure pf iron, (Plate VII,) due, it is supposed, entirely 
 to the different rate of cooling or freezing from the liquid to the solid 
 state, are not sufficiently attended to by metal workers. The finer the 
 molecular structure, the stronger and better the fabrication made from 
 the iron. In wrought iron the same differences of size of grain can 
 be seen. With this knowledge I designed the guns shown on Plates 
 XIII and XIV. 
 
 30. Q. It has been represented to us that fibrous wrought iron is much 
 stronger than crystallized iron ; is that so f 
 
 A. Undoubtedly j even to a greater degree than the fine-grained cast 
 iron excels in tenacity, elasticity, and density the coarse-grained iron. 
 The difference of structure is shown in Figs. 5 and 6, Plate XI. In a 
 mass as large as is required for a gun there is no such thing as fibre ; 
 the structure is entirely changed by cooling from or heating to the weld- 
 ing temperature, as slowly as a large mass must be heated or cooled ; 
 the molecular structure is entirely changed by once heating to the weld- 
 ing temperature, if the mass is large. 
 
 31. Q. Among the forces which you have mentioned as resulting from 
 the combustion of gunpowder, you have referred to the expansive force ; 
 is not that a principal force to be restrained, and can it be restrained ? 
 
 A. It can ; the whole of the expansive force of gunpowder under com- 
 bustion has been frequently restrained when fired in a chamber which 
 it filled. I have conducted such experiments myself, and have heard of 
 the experiments of others, in which the force was restrained completely. 
 However, if I were about to design or make a gun of any calibre which 
 had been made previously by any other person of the same material and 
 which had endured one or two heavy charges equal in weight of and 
 rapidity of combustion of the charge I wished to use, I would depend 
 upon the data relating to strength by thickness of wall in that gun, and 
 adopt equal or greater area of cross and longitudinal sections ; then, by 
 increased tenacity, density, and elasticity in the metal used, get a 
 margin of strength to restrain the direct pressure. I would then take 
 care to have 110 injurious tensions from the rate of cooling, and with the 
 elasticity which my improved model would give to provide for the une- 
 qual expansion, I would expect to get a gun which would absolutely 
 restrain the direct pressure, and permit the unequal expansion resulting 
 from firing, which need not be restrained. 
 
 32. Q. What is initial tension, so frequently referred to, and how does 
 it affect the endurance of guns I 
 
 A. Initial tension is an inert force or strain, inaugurated in a gun or 
 any other piece of metal, induced usually by unequal cooling, causing 
 one part of the mass to endeavor to pull away from or towards another 
 part, or both. The part which cools first in any mass is subjected to a 
 strain of compression, and the part which cools last to a strain of exten- 
 sion. The castings, Plate XV, which I have prepared and exhibited to the 
 committee, lately placed in the hall of the old House of Bepresentatives, 
 were intended to represent the excess of this tension from unequal cool- 
 ing. These castings were referred to in a late report of the Chief of 
 Ordnance, General Dyer, as having been prepared by u ignorant or 
 designing persons," and the maker was credited with having hindered 
 the furnishing by the department of 1,915 large guns. I hope you will 
 credit me with having prevented the perpetration of a gigantic swindle 
 upon the treasury thereby. 
 Eep. No. 266 8 
 
114 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 Metals expand while being heated with a force which exactly equals 
 the measure of their ability to resist compression at each different tem- 
 perature if their expansion be resisted sufficiently, and contract in cool- 
 ing with a force which equals the resistance to extension of the same 
 metal. These experimental castings, it may be seen, have broken in 
 their strongest part, where the area of cross-section ruptured is twelve 
 square inches. If we assume the tensile strength of the iron to be only 
 20,000 pounds to the inch, the tension necessary to break it amounted 
 to 240,000 pounds, the outside bars having a larger amount of cooling 
 surface, while the quantity of metal to be cooled is less, became frozen 
 while the iron of the middle bar was in the liquid state. The later con- 
 traction of the part cooled last (the contraction being restrained by the 
 rigidity of the part cooled first) was the cause of the rupture. If the 
 length of the casting had been less it might have happened that the 
 extent of the contraction of the middle bar would have been within the 
 " permanent elasticity," and the measure of ductility of the iron ; it 
 would not in that case have been broken, although the tension might 
 have been nearly great enough to break it ; it would then be in the 
 state of initial tension. It can be seen that a casting might be made 
 and strained so nearly to the point of rupture, that the heat of the hand, 
 (if warmer than the iron,) laid upon the compressed part, would be suf- 
 ficient to complete the rupture or burst it. 
 
 Those Rodman guns which have burst in the foundry previous to hav- 
 ing been subjected to the powder proof, were burst by the excess of the 
 initial tension, caused by cooling the gun, or the cast block from which 
 the gun was to be made, from the interior"? 
 
 33. Q. Are the views contained in your evidence in relation to metals, 
 force of powder, and endurance of guns, confirmed by the opinions of 
 experts, by the reports, and by recorded authorities? 
 
 A. They are my conclusions, based upon a careful reading of reports 
 and authorities, upon my own practical experience as a metal worker, 
 my own experiments and observations as a gun maker, and a long and 
 earnest study of the natural philosophy involved in the subject. If you 
 will permit me, I will revise my evidence and interpolate references to 
 the reports, authorities, and experiments' upon which my statements are 
 founded. 
 
 34. Q. You can do so. How will the cost of testing guns upon the 
 plan you have proposed compare with the system now practiced by the 
 army and navy ordnance departments ? 
 
 A. The cost would be immeasurably less, as the extreme proof would 
 determine at once the quality of the gun and of all other guns made of 
 the same calibre, form, or model, material, and manipulation of material ; 
 while it can be seen that the old extreme proof determined nothing except 
 that the particular gun tried either burst or did not burst, enlarged or 
 did not enlarge; that the vent either did or did not wear, and that the 
 interior either cracked or did not crack. The uncertainties attending 
 the proof of guns are referred to frequently in the reports a's u incon- 
 gruous results, 77 while the question relating to the endurance of guns 
 remains involved in mystery. General Dyer, in his last report, dated 
 October 19, 1868, says: 
 
 In the last annual report from this office the unanimous opinion of the board on the aruia^ 
 ment of the fortifications ****** was quoted, showing the necessity of a large 
 number of smooth-bore and rifle cannon for such armament. In pursuance of this opinion, 
 approved by the War Department, and at the request of the Chief of Engineers, a few of 
 these cannon have been ordered, and are now nearly finished and ready for trials to test their 
 power and endurance. 
 
 In the report of the same officer for the preceding year, the endurance 
 
EXPERIMENTS ON HEAVY ORDNANCE. 115 
 
 of a 12-inch Eodraan rifle gun was referred to as establishing that guns 
 of that class exhibited endurance superior to any gun of the calibre in 
 the world, without referring to the important fact that four only of that 
 kind of gun had ever been made, and that three of them had burst pre- 
 viously to the date of that report. Since that time the fourth one has 
 burst, and it is now rumored that two or three others referred to in the 
 report of October 19, 1868, as of the few which have been ordered, have 
 been disabled during the experiments on iron defences by the engineers. 
 The extraordinary part of this business is that while the ordnance depart- 
 ment of the army is engaged apparently in efforts to bolster up the 
 character of guns which fail so suddenly that it is difficult to make the 
 report and print it before the guns are disabled, the Chief of Ordnance 
 of the navy says, in his corresponding annual report: 
 
 Opinions differ quite as widely (referring apparently to almost every question involved in 
 designing, constructing, mounting, and using ordnance) in regard to the preferable mode of 
 developing ordnance power ; whether it shall be by smooth or rifle bores ; by loading at 
 breech or muzzle ; made of iron, cast or wrought, or from steel; solid, or in connected parts. 
 The relation of mass to velocity is also unsettled. 
 
 It seems to me that it is plainly the duty of Admiral Dahlgren to 
 report his own conclusions in relation to these important points, while it 
 seems also quite as plain that he prefers to continue expending public 
 money in repeating old worn-out kinds of experiments, and recording 
 the most minute and inconsequential facts in relation to such experi- 
 'ments, instead of wrenching himself in the public service, to the extent he 
 would if he should advance an original idea*>r give an opinion with a reason. 
 Who is there so ignorant about ordnance in these days as not to 
 know, for instance, whether it is practicable or better to load guns of 
 the larger calibres at the breech, after the exhaustive experiments con- 
 ducted in England with the Whitworth and Armstrong guns, if the guns 
 did not fail ; and that the return to muzzle-loaders in that country for 
 large calibres was on account of the failure of the guns, and not other- 
 wise ! Who does not know the relation of mass to velocity ? Mass or 
 weight is one element of ability in a projectile to perform work, and velo- 
 city the other. Could not all the experience of Admiral Dahlgren enable 
 him to state as a fact, that a projectile, however heavy or large it might 
 be, could not penetrate air, water, wood, earth, stone, or iron, if it had 
 no motion or velocity, and that it could not do so either, even with 
 velocity or motion, if it had no mass or weight? Has Admiral Dahlgren 
 never seen the calculations of Captain Noble, of the royal artillery of 
 England, of the foot tons of work per inch of circumference, stored up 
 in projectiles having different weights and velocities, or the simple rule 
 upon which the calculation is made? If he has not, what is the use of 
 continuing expenditures of public money for experiments under such 
 obtuse direction ? No valuable conclusion can ever be arrived at in so 
 indirect a manner. On the 22d of November, 1862, this same officer, in 
 his report as Chief of Ordnance, referring to " the construction and 
 armament of our ships of war," said: "And yet no definite conclusion 
 has been reached in regard to either of these important problems;" and, 
 although a war was then raging, referred on the same page to the part 
 of the question relating to the guns, with the refreshing complacency 
 exhibited in the following quotation: "so that we have the leisure to 
 consider and devise any other species of ordnance that may be better 
 adapted to the purpose, and are not precipitated inlo hasty or questionable 
 measures." Obtuseness and complacency of the navy ordnance bureau 
 is, however, no more effectually opposed to progress in the art of pro- 
 ducing guns, than the politic shrewdness or smartness of the army 
 
116 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 ordnance corps, and their selfishness in precluding from the sacred 
 precincts of the inner sanctuary of the department all inventors of guns. 
 
 35. Q. After a gun has burst could you determine whether it was 
 pressure of the powder, toa great tension, or too little, or the unequal 
 heating from the interior which was the principal cause of the rupture 
 from the nature of or direction of the fracture ? 
 
 A. I think we can determine that almost with certainty. It is to be 
 noticed that all unbanded guns burst with such uniform direction of 
 fracture as to lead to the conclusion that the bursting is according to 
 law ; at the same time this direction is not that one which could possibly 
 result from pressure of the powder alone. About twenty years since Gen- 
 eral Rodman proceeded to consider the forces acting to burst a gun, and 
 assumed the gun to be made up of staves shown by diagrams in his re- 
 ports, (see Plate Y, Fig. 1 and Fig. 3,) and assumed correctly enough that 
 the effect of this pressure would be to bend these imaginary staves out- 
 ward, as shown in Fig. 1, Plate Y. He then erected a diagram to show 
 the kind of fracture which would result from pressure; in this he was also 
 singularly correct. This kind of fracture is shown by Fig. 1, Plate Y. 
 Its correctness is shown by the fracture of a cylinder actually burst by 
 water pressure during one of his experiments, (see Fig. 7, Plate Y.) Now 
 I believe myself to be the only person who ever asked attention to the 
 fact that this kind of fracture is a kind that never occurred to a gun 
 burst by firing. I was surprised to find that General Rodman, however, 
 had not yet seen the point which I have urged in this connection for the 
 past six years, for in giving his testimony before this committee a few 
 days since, he referred to the staves and the strength of the breech as 
 If no other force but the pressure of the gas measured by his instrument 
 had anything to do with the bursting of guns behind the bottom of the 
 bore, where the pressure don't act at all. and expressed the opinion that 
 the gun shown in Fig. 2, Plate II, began to rupture at the breech and 
 split forward, and he treated the subject very tenderly when describing 
 the bursting of guns on improved models, Plates II and III, which broke 
 through the breech in the same manner, although they have a greater 
 thickness at that part. Plates II and III exhibit the general direction of 
 fracture in all unbanded guns; and Fig. 4, Fig. 5, and Fig. 6, Plate Y, 
 are intended to show why guns burst through the breech and refuse 
 to follow the direction of fracture due to pressure alone, according to the 
 diagram, Fig. 2, Plate Y, Fig. 4, same plate, shows the curved form 
 which the two outside plates of three iron ones would assume if heat 
 should be communicated to their inside surfaces only by heating the 
 middle plate red hot and adjusting it between the other two, when cold 
 and straight. By imagining three such plates placed upon the diagram of 
 a burst gun, as in Fig. 6, Plate Y, the cause of the invariable bursting 
 through the breech in guns of this kind can be understood. The heat 
 added to the interior of the gun causes the extension lengthwise of the 
 interior iron, and forces the reinforce into the curved form shown in Fig. 
 4, Plate IY. This is also illustrated in Fig. 1, Plate Y. The reinforce 
 extended by the expansion of the interior and the refusal of the exterior 
 to extend with it is the principal cause of the rupture undoubtedly. 
 
 The Parrott banded gun, Fig. 1, Plate I, has the same character of 
 fracture from the same cause. If a narrow band had been placed on 
 the columbiad, Fig. 1, Plate YI, just over the seat of the shot, although 
 it might have prevented the rupture under the band, it would have had 
 no tendency to have prevented that part of the rupture reaching from 
 forward of the trunnions back to the band; and this explains that kind of 
 rupture shown in the Parrott gun, Fig. 4, Plate I, Fig 5, Plate I, 
 
EXPERIMENTS ON HEAVY ORDNANCE. 117 
 
 which, however, only cracked on the outside. Ruptures along the chase 
 and at the muzzle have been sufficiently explained in answer to previous 
 questions. It is important to consider the cause of the blowing out of 
 the breech. Plate X, Fig. 1, shows a Whitworth gun, which was 
 one of two disabled in the naval battery on Morris island; the inner tube 
 extended and protruded one inch, as shown. This inner tube would 
 not have extended so far out at the breech if it had been allowed to ex- 
 pand when heated by firing in all other directions. The bands prevented 
 it from expanding radially. If the band had been shrunk on with screw 
 threads fitting upon the inner tube so as to prevent extension lengthwise 
 as well as radially, the gun would have burst with the same direction of 
 fracture as is shown in columbiad, Fig. 2, Plate V, or else it would have 
 broken transversley in the same manner the 300-pounder Armstrong, Figs. 
 3 and 4, Plate X, broke, i. e. s transversely; so also the heating the Parrott, 
 Fig. 2, Plate X, only half way through the wall of cast iron under the band 
 had the tendency to expand the interior radially and longitudinally, but 
 its expansion (rememember only heated half the thickness of the cast iron 
 from the inside) was restrained radially by the band. The result was, the 
 breech was pushed out just the same as the 300-pounder Armstrong, 
 Fig. 4, Plate X. Thus it can be seen that unequal expansion of the 
 metal of the gun from the interior, resulting from the direct heat of 
 the gas of the powder undergoing combustion, or the heat coming from 
 friction, is the principal cause of all the different kinds of ruptures of 
 guns. 
 
 APPENDIX B. 
 
 Correspondence. 
 
 WASHINGTON, D. 0., December 24, 1868. 
 
 SIB : I have the honor to request that you will furnish as soon as prac- 
 ticable answers to the following questions, for the information of the 
 Joint Select Committee on Ordnance: 
 
 1. What different calibres and kinds of guns larger than 32-pounder 
 smooth-bores and 30-pounder rifles are now mounted on or prepared for 
 the fortifications? 
 
 2. What is the nature of the proof or experiments to which the different 
 kinds and calibres before mentioned have been subjected to respectively 
 to enable the department to determine upon the propriety of accepting 
 the guns for service? 
 
 3. How many rifled guns of 8-inch calibre or larger, cast hollow, have 
 been made either for the army or the navy, and subjected to proof or ex- 
 periment! What has been the endurance of each of the guns? What 
 is the present state of each, and what was the nature or extent of the 
 proof on experiments in each case I 
 
 4. What guns cast hollow for the army have exhibited cracks or rup- 
 tures on the outside previous to being subjected to the powder proof, 
 together with the nature and extent of the rupture? 
 
 Very respectfully, your obedient servant, 
 
 J. M. HOWARD, 
 Chairman Joint Select Committee on Ordnance. 
 
 Lieutenant Colonel T. J. TREADWELL, 
 
 Acting Chief of Ordnance, Washington, D. C. 
 
118 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 ORDNANCE OFFICE, WAR DEPARTMENT, 
 
 Washington, January 23, 1869. 
 
 SIR: I have the honor to report as follows in reply to your communi- 
 cation of the 24th ultimo : 
 
 Question 1. What different calibres and kinds of guns, larger than 
 32-pounder smooth-bores and 30-pounder rifles are now mounted on or 
 prepared for the fortifications ? 
 
 There are mounted or ready to be mounted at the forts as follows: 
 
 SMOOTH-BORES. 
 
 1 20-inch Eodman gun. 
 294 15-inch Eodman guns. 
 
 1 13-inch Eodman gun. 
 1, 233 10-inch Eodman guns. 
 
 147 10-inch columbiads. 
 155 8-inch Eodman guns. 
 339 8-inch columbiads. 
 30 8-inch sea-coast howitzers. 
 
 33 8-inch siege howitzers. 
 143 42-pounder guns. 
 
 2 16-inch mortars. 
 
 17 13-inch mortars, sea-coast. 
 2 12-inch mortars, sea-coast. 
 
 34 10-inch mortars, sea-coast. 
 59 10-inch mortars, siege. 
 
 26 8-inch mortars, siege. 
 
 2, 516 total smooth-bores. 
 
 RIFLED GUNS. 
 
 2 12-inch Eodman guns. 
 28 300-pounder Parrott guns. 
 48 200-pounder Parrott guns. 
 133 100-pounder Parrott guns. 
 34 4J-inch siege guns. 
 
 245 total rifled guns. 
 
 Besides the foregoing there are at the arsenals, available for mounting 
 
 SMOOTH-BORES. 
 
 2 15-inch Eodman guns. 
 24 10-inch Eodman guns. 
 
 8 10-inch columbiads. 
 46 8-inch Eodman guns. 
 63 8-inch columbiads. 
 15 9-inch Dahlgren guns. 
 
 2 10-inch sea-coast howitzers. 
 
 6 8-inch navy guns. 
 58 8-inch sea-coast howitzers. 
 184 8-inch siege howitzers. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 119 
 
 31 42-pounder guns. 
 1 16-inch mortar. 
 
 41 13-inch mortars, sea-coast. 
 
 70 10-inch mortars, sea-coast. 
 
 30 8-inch mortars, sea-coast. 
 124 10-inch mortars, siege. 
 154 8-inch mortars, siege. 
 
 859 total smooth-bores. 
 
 RIFLED GUNS. 
 
 1 8-inch Eodman gun. 
 
 11 300-pounder Parrott guns. 
 33 200-pounder Parrott guns. 
 55 100-pounder Parrott guns. 
 
 12 7-inch wrought-iron guns. 
 73 42-pounders, banded. 
 
 75 4J-inch guns. 
 107 32-pounders, banded. 
 
 367 total rifled guns. 
 
 RECAPITULATION. 
 
 Smooth-bores. Rifled. 
 
 At forts 2, 516 245 
 
 At arsenals 859 367 
 
 Total 3, 375 612 
 
 Question 2. What is the nature of the proof or experiments to which 
 the different kinds and calibres before mentioned have been subjected 
 respectively to enable the department to determine upon the propriety 
 of accepting the guns for service f 
 
 Prior to 1861 the proof of iron guns was three rounds two with a 
 charge of powder equal to one-half of the weight of the shot, two shot 
 and one wad ; the third a charge of powder one-third the weight of the 
 shot, one shot and one wad. 
 
 For columbiads the proof was two rounds 10-inch, first round, 20 
 pounds of powder, one shot, and one wad; second round, 24 pounds of 
 powder, one shot, and one wad. 
 
 For the 8-inch first round, 12 pounds of powder, one shot, and one 
 wad ; and for the second round, 15 pounds of poAvder and one shell. 
 
 The proof of howitzers and mortars was a corresponding scale. 
 
 In 1861 the proof for all guns was fixed as follows : (Ordnance Manual, 
 1861, page 30:) 
 
 15-inch columbiad, 3 rounds, 50 pounds powder, and 1 shell. 
 10-inch columbiad, 3 rounds, 18 pounds powder, and 1 shot. 
 8-inch columbiad, 3 rounds, 12 pounds powder, and 1 shot. 
 32-pounder gun, 3 rounds, 9 pounds powder, and 1 shot. 
 24-poundor gun, 3 rounds, 8 pounds powder, and 1 shot. 
 18-pounder gun, 3 rounds, 6 pounds powder, and 1 shot. 
 12-pounder gun, 3 rounds, 4 pounds powder, and 1 shot. 
 
120 EXPEKIMENTS ON HEAVY OKDNANCE. 
 
 8-inch siege howitzer, 3 rounds, 4 pounds powder, and 1 shot. 
 
 24-pounder howitzer, iron, 3 rounds, 3 pounds powder, and 1 shot, strapped. 
 
 Field guns, bronze, 3 rounds, $ weight of shot, and 1 shot, strapped. 
 
 32-pounder howitzer, bronze, 3 rounds, 3 pounds powder, and 1 shot, strapped. 
 
 24-pounder howitzer, bronze, 3 rounds, 2- pounds powder, and 1 shot, strapped. 
 
 12-pounder howitzer, bronze, 3 rounds, 1 pounds powder, and 1 shot, strapped. 
 
 12-pounder mountain howitzer, bronze, 3 rounds, pound powder, and 1 shot, strapped. 
 
 Coehorn mortar, 3 rounds, pound powder, and 1 shell. 
 
 13-inch sea-coast mortar, 3 rounds, 20 pounds powder, and 1 shell. 
 
 10-inch sea-coast mortar, 3 rounds, 10 pounds powder, and 1 shell. 
 
 10-inch light mortar, 3 rounds, 5 pounds powder, and 1 shell. 
 
 8-inch light mortar, 3 rounds, 2 pounds powder, and 1 shell. 
 
 4^-inch rifled siege guns, 3 rounds, 4 pounds powder, and 1 shot. 
 
 3-inch rifled siege guns, 3 rounds, 1^ pounds powder, and 1 shot. 
 
 In January, 1862, when it was determined that guns should be cast 
 hollow and cooled from the interior, the following requirements were 
 prescribed : That one trial gun should be made by each founder receiv- 
 ing orders ~or accepting a contract; the gun should be made of warm 
 or cold blast charcoal iron, to have a tenacity of not less than 30,000 
 pounds per square inch, to be determined by specimens taken from the 
 sinking head of the gun and from a cylinder cast from the same heat 
 and from the same metal ; the trial guns to be fired 1,000 rounds with 
 service charges of powder, 200 with solid shot and 800 with shells, and 
 if the gun stood the test the order to be filled with guns made of the 
 same metal treated in the same manner, and to be received upon endur- 
 ing the proof established in 1861. 
 
 The 7-inch wrought-iron rifles were proved by firing 10 rounds with 
 20 pounds of powder and one shot weighing 125 pounds. 
 
 The rifled guns heretofore procured having been considered entirely 
 as experimental, a provisional proof was fixed for such guns. 
 
 The Parrott rifle guns were procured as a necessity during the war, 
 but before putting them in service one 100-pounder was subjected to a 
 test of 1,000 rounds with charges of 10 pounds of powder and one shell, 
 which it endured ; subsequently the 200-pounders and 300-pounders were 
 subjected, one of each to a test of 100 rounds the 200-pounder with 
 charges of powder of 15 and 16 pounds, and one shell of 150 pounds, and 
 the 300-pounder with charges of 25 pounds of powder and one shell 
 weighing 252 pounds, which test they endured. 
 
 All guns of these three calibres subsequently procured were proved 
 with 10 rounds of similar charges. 
 
 In the fall of 1864 the department appointed an officer to superintend 
 the construction of cannon, with authority to dictate to founders the kinds 
 of metal they shall use, the manner in which it shall be treated, and the 
 properties it shall possess after being cast into guns, such as tenacity, 
 specific gravity, initial strain, and texture of fracture. These being satis- 
 factory, the responsibility of the powder-proof was assumed by the depart- 
 ment. All guns cast hollow and cooled from the interior, since that 
 period, have been received on these conditions, but are, nevertheless, 
 subjected to proof according to the regulations of 1861. 
 
 The ordnance board, at its meeting of January, 1868, fixed the proof 
 of 15 and 13-inch guns at two rounds of 100 pounds of powder and one 
 solid shot for the former, and the same number of rounds of 80 pounds 
 of powder and one solid shot for the latter, and further recommended 
 that all 15-inch guns heretofore procured, whether proved or not, should 
 be proved with this charge of 100 pounds of powder and one shot. This 
 will be done as fast as the guns are mounted, or other suitable facilities 
 afforded for the purpose. 
 
 Question 3. How many rifled guns of 8-inch calibre, or larger, cast 
 
EXPERIMEMTS ON HEAVY ORDNANCE. 121 
 
 hollow, have been made either for the army or the navy and subjected 
 to proof or experiment I What has been the endurance of each of the 
 guns ? What is the present state of each, and what was the nature or 
 extent of the proof or experiments in each case ? 
 
 The number of rifled cannon of 8-inch calibre and larger, cast hollow, 
 which have been procured by this department, is as follows : 
 
 Three 12-inch Eodman guns; three 8-inch Rodman guns; forty-one 
 200-pounder Parrott guns ; forty 300-pounder Parrott guns. 
 
 The first 8-inch rifle, which was made at Fort Pitt foundry, was sub- 
 mitted to a test of 1,047 rounds with charges ranging from 9 to 16 pounds 
 of powder and one projectile, and burst at the last round. 
 
 Two 8-inch rifles were subsequently made at the South Boston foundry, 
 and were tested, one with flanged and the other with expanding projec- 
 tiles, and with charges of powder ranging from 14 to 16 pounds. 
 
 The one fired with flanged projectiles burst at the 80th round ; the one 
 fired with expanding projectiles has endured 808 rounds and is still ser- 
 viceable. 
 
 The first 12-inch Eodman rifle was fired 472 times, with charges 
 ranging from 35 to 70 pounds of powder, principally 50 pounds, and one 
 projectile, and burst at the last round. 
 
 A 12-inch gun, cast hollow and rifled on the Atwater principle, was 
 turned over to the ordnance department by the navy, and was tested at 
 Fort Monroe. The history of this gun, prior to its transfer, is not known. 
 It was fired at Fort Monroe, 30 rounds with from 50 to 55 pounds of 
 powder and one expanding shot or shell, and burst at the last round. 
 
 Two 12-inch Eodman rifles were recently procured and have been fired, 
 one at Fort Monroe and the other at Fort Delaware. 
 
 Detailed reports of the firing made with rifled guns have heretofore 
 been furnished to the committee, except the firing of 8-inch South Boston 
 rifle, No. 2, subsequent to the 771st fire, the 12-inch No. 1 from the 428th 
 to the 472d fire, and the firing with the last two 12-inch rifles ; and copies 
 of these reports are appended hereto. 
 
 Copies of the preliminary experiments made with the Parrott 200- 
 pounders and 300-pounders have also been heretofore furnished to the 
 committee, and are respectfully referred to. Two of these 300-pounders 
 and eleven 200-pounders have failed in service; but it cannot be stated 
 what portions of these were cast hollow or solid. 
 
 Question 4. What guns cast hollow for the army have exhibited cracks 
 or ruptures on the outside previous to being subjected to the powder 
 proof, together with, the nature and extent of the rupture I 
 
 No gun cast hollow for the army which exhibited cracks or ruptures 
 on the outside previous to being subjected to powder proof has been 
 offered by the founder, or received by the United States. Several such 
 guns, to the number of 98, exhibiting defects, were made for the army, 
 but were either withdrawn by the founders or rejected by the inspectors. 
 
 The nature and extent of the defects, as described in the manufac- 
 turers' reports, are as follows : 
 
 15-inch guns 6 
 
 10-inch guns 82 
 
 8-inch guns 1 
 
 300-pounder Parrott 1 
 
 8-inch siege mortars 8 
 
 Of the first, two were for dra wholes, one for being too large in bore, 
 
 one for too low tenacity, one cracked in lathe, and one condemned in pit. 
 
 Of the second, sixteen were for drawholes, twelve for holes in bore, 
 
122 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 thirty-one for low tenacity, one for high density, one for metal too soft, 
 seven failed in casting, and nine failed in mechanical tests, one for too 
 much initial strain, one condemned in mill, two cracked, and one burst 
 in lathe. 
 
 The 300-pounder condemned in mill. 
 
 The 8-inch gun for holes in muzzle, and the 8-inch siege mortars con- 
 demned by the founder. 
 
 Very respectfully, your obedient servant, 
 
 T. J. TBEADWELL, 
 
 Bvt. Lieut. Col. and Major of Ordnance, in charge. 
 Hon. J. M. HOWARD, 
 
 Chairman Joint Select Committee on Ordnance, U. S. Senate. 
 
 WASHINGTON, D. 0., December 24, 1868. 
 
 SIR : I have the honor to request that you will furnish, for the infor- 
 mation of the Joint Select Committee on Ordnance, answers to the 
 following questions: 
 
 1. What is the total number, kinds, calibres, and weights, respectively, 
 of guns now or at any time mounted on iron-clad ships of the United 
 States, from the time of the arming of the first monitor to the present 
 time? 
 
 2. How many trial guns were originally or at any time procured or 
 fired to extreme proof as the basis of the acceptance of the different kinds 
 and calibres of guns mounted on such iron-clad ships ? 
 
 3. What was the character of the extreme proof, ^ordinary proof, and 
 experiments, to which each system, kind, and calibre, was severally sub- 
 jected'? 
 
 4. How far has the navy Ordnance Bureau accepted the tests, proofs, 
 and experiments made by the army ordnance department towards 
 enabling the bureau to determine what kind of guns should be adopted 
 for service, and how far, within the knowledge of the bureau, has the 
 army ordnance department accepted the tests, proofs, and experiments 
 of the navy as conclusive towards enabling it to determine the proper 
 system to be adopted in arming the fortifications with heavy guns? 
 
 5. What fissures, cracks, and ruptures, (together with the locality and 
 extent of the same,) have at any time been noticed or reported to the 
 bureau as having occurred on the outside of guns larger than 32-pounders, 
 previous to the guns having been subjected to the powder proof; also, 
 what cracks, fissures, and ruptures have been noticed or reported on the 
 inside of guns previous to firing; together with the kind of gun, and 
 whether the notice or report was official or otherwise? 
 
 6. What fissures or cracks have been reported to the bureau as having 
 occurred upon the outside or inside of guns larger than 32 pounders, 
 during proof or experiments with powder, together with the nature or 
 extent of the accident, where the gun was not completely burst? 
 
 7. What was the nature of the extreme proof and the ordinary proof 
 prescribed for guns of large calibre by the bureau in the years 1850, 
 1855, 1860, and 1865, and also at the present time; also, so far as is 
 known to the bureau, what was the extreme proof and ordinary proof 
 for like guns prescribed by the army ordnance department at the same 
 dates? 
 
 8. On what occasion was the 15-inch gun subjected by the navy to 
 the most rapid firing for as many as fifteen consecutive rounds, with shot 
 or shell, and with nearly uniform intervals of time between the shots ; 
 
EXPERIMENTS ON HEAVY ORDNANCE. 123 
 
 what interval of time elapsed between the respective rounds, and fur- 
 ther, whether the gun was fired in service or during experiments ; also, 
 what official knowledge, if any, is possessed by the bureau of 15-inch 
 guns having been fired by the army in a similar manner in service or 
 during experiments ? 
 
 9. Give like information with regard to the 8 and 10-inch Parrott rifles. 
 
 10. What has been the most rapid firing for any number of consecu- 
 tive rounds with the 15-inch gun, the larger Parrott rifles, or the hollow 
 cast rifles, with nearly uniform intervals between the shots? 
 
 11. What 15-inch guns or rifles of large calibre were injured, disabled, 
 or burst while in service during the late war, or while undergoing proof 
 or experiment, together with the nature of the gun and the character of 
 the injury? 
 
 12. What system of rifled guns of 150 pounds calibre or larger have 
 been subjected to proof or experiment by the navy? What guns of that 
 calibre, or larger, have been adopted or accepted for experiment by the 
 navy? 
 
 13. To what proof on experiments has each system and calibre which 
 has-been accepted been subjected? Which system exhibited the greatest 
 endurance? Which the least? What has been the average endurance of 
 each system and calibre for all the guns made, tested and experimented 
 with ? What system of rifled guns of large calibre is now approved by 
 the Ordnance Bureau of the navy ? 
 
 The committee respectfully request that answers to these questions be 
 given as early as practicable. 
 
 Very respectfully, your obedient servant, 
 
 J. M. HOWAED, 
 
 Chairman Joint Select Committee on Ordnance. 
 Bear- Admiral JOHN A. DAHLGREN, 
 
 Chief of Ordnance, Navy Department, Washington, J). C. 
 
 BUREAU OF ORDNANCE, NAVY DEPARTMENT, 
 
 Washington City, February 11, 1869. 
 
 SIR : I have the honor to transmit herewith replies to the questions of 
 your honorable committee, which, I regret to say, are more or less incom- 
 plete. 
 
 I have done, however, as much as the time has permitted since receiv- 
 ing the wishes of the committee on the 25th of December last. 
 I am, sir, with great respect, your obedient servant, 
 
 J. A. DAHLGEE^, 
 Rear-Admiral and Chief of Bureau. 
 Hon. JAMES M. HOWARD, 
 
 Chairman Joint Select Committee on Ordnance, U. S. Senate. 
 
 Reply to query 1. 
 
 There have been three calibres of cannon mounted on sea-going iron- 
 clads of the navy, viz : 
 
 Pounds. 
 
 11-inch, of my design, smooth bore 16,000 
 
 Short 15-inch, of my design, smooth bore 42,000 
 
 Long 15-inch, not of my design 42,800 
 
 Eifled 8-inch (150-pouuder) Parrott 16,500 
 
124 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 The first monitor carried two 15-inch guns. 
 
 The vessels of the class next built were larger, and most of them 
 carried in the turret one 15-inch (short) gun and one 11-inch, such as 
 the Passaic, Moiitauk, Katskill, Weehawken, Nantucket, Nahant, and 
 Sangamon. 
 
 Two of them carried a 15-inch (short gun) and a Parrott 8-inch rifle, 
 viz : Patapsco and Lehigh. 
 
 The Mont-auk's short 15-inch was replaced by a long 15-inch, and that 
 subsequently by another long 15-inch. 
 
 The next class of monitors carried in the turrets two short 15-inch 
 guns, viz: Tecuinseh, Manhattan, Canonicus, Saugus, Camanche. 
 
 Some had two long 15-inch, such as the Maiiayuiik, Tippecanoe, 
 Catawba, and Oneota, which were built in the western inland waters, 
 but were capable of ocean service. 
 
 The double- turret monitors had four 15-inch, viz : the Monadnock, 
 Miantonoinah, Tonawanda, Agaruenticus. 
 
 The large ocean monitor Dictator carried two 15-inch in the turret. 
 
 The Roanoke, with three turrets, had a 15-inch and an 11-inch in one 
 turret, a 15-inch and 150-pouuder in the second turret, and an 11-inch 
 and 150-pounder in the third turret. 
 
 The river monitors of one and two turrets had only 11-inch in each 
 turret, viz: Marietta, Saudusky, Osage, Ozark, Neosho, Unipqua, Win- 
 nebago, Milwaukee, Chickasaw, and Kickapoo. 
 
 The Keokuk fixed turrets had one 11-inch in each. 
 
 The Onondaga had two short 15-inch and two 150-pounder Parrotts. 
 
 The New Ironsides had a covered battery of 14 11-inch and two 150- 
 pounder Parrotts. 
 
 The Dunderberg was pierced for 16 guns, but never carried more than 
 two 15-inch (long) and four 11-inch in battery. 
 
 CHANGES IN THE BATTERY. 
 
 The query includes guns that have been carried, as well as those which 
 are now carried. I have to state that two of the Monadnock's 15-inch 
 Nos. 24 and 27 (both short) were surveyed, condemned, and sold, 
 (December, 1865,) and replaced by two long 15-inch Nos. 82 and 86. 
 
 One 15-inch in the Miantonomah has been ascertained, after her return 
 to the United States, to be bored four inches too deep, and is, therefore, 
 condemnable, and must be replaced. 
 
 The Saugus's short 15-inch (No. 29) was split, and replaced by another, 
 (No. 57 long.) 
 
 The Patapsco's rifled 150-pounder Parrott, No 6, was cracked in action 
 and replaced by No. 40. The second gun, No. 40, was also cracked, and 
 replaced by a third, No. 35, which was on board when the vessel was 
 sunk by a torpedo at the entrance of Charleston harbor. 
 
 The Lehigh's 15-inch, (short,) No. 13, was cracked and sold, being 
 replaced by No. 16, (short.) 
 
 The Passaic's 11-inch was replaced in 1863, at New York, by an 8-inch 
 rifle no defect in the 11-inch. 
 
 The Montauk's short 15-inch, No. 4, and 11-inch, were replaced by 15- 
 inch, Nos. 56, and 80, (both long guns.) It does not appear that these 
 guns were displaced on account of defects, but only to make way for two 
 long 15-inch. 
 
 The length of the first 15-inch, designed by myself, was much reduced 
 in order to accommodate it to Mr. Ericsson's method of firing with the 
 muzzle inside the turret 5 which was intended to avoid cutting the large 
 
EXPERIMENTS ON HEAVY ORDNANCE. 125 
 
 apertures in the turret that would be necessary for the muzzle of the 
 15-inch, if they passed through the wall of the turret so as to be outside 
 when fired. The firing inside made it necessary to box the muzzle so as 
 to exclude the smoke, and it was found that these boxes were liable to 
 be disabled frequently in action by the excessive shock of the discharge. 
 15-inch guns were, therefore, cast of greater length, so as to pass out- 
 side the turret, and were reduced at the muzzle so as to have the aper- 
 ture as small as possible. In doing so the gun was made too thin at 
 the extremity of the chase. 
 
 I drafted the original navy 15-inch gun; the responsibility of the 
 modified draft has been assigned to the Chief of the Bureau of Ordnance. 
 (See memorandum Report of Committee on Ordnance, p. 131.) 
 
 The total number of guns now or at "any time mounted in iron-clad 
 ships of this navy," as given in the preceding statement, may be summed 
 thus: Short 15-inch, 27; long 15-inch, 33; 11-inch, 98; 150-pounders, 16. 
 
 Reply to query 2. 
 
 THE 15-INCH GUN. The circumstances under which this class of gun 
 was brought into our naval service were so urgent and abnormal as to 
 impose on the bureau the necessity of some deviation from the formula 
 usually prescribed in respect to a trial gun as a basis of reception from 
 the founders. 
 
 The extraordinary efforts of the rebel government had enabled it to 
 precipitate an iron-clad ram upon our blockading force in Hampton 
 Roads in March, 1862, which, being composed of wooden vessels, suf- 
 fered severe loss from the attack, and would have been entirely destroyed 
 the next day if the Ericsson monitor had not providentially arrived in 
 season to frustrate the further progress of the ram. The moment was 
 critical, for just then our army was on the eve of /moving upon Rich- 
 mond, and the transports assembled in the Chesapeake for that purpose 
 were endangered. 
 
 The Navy Department satisfied, as it might well be, with the signal 
 success of the monitor, immediately took measures to build a number of 
 like model, but larger, so as to carry heavier ordnance ; the choice of 
 which the Navy Department itself assumed, and directed the Bureau of 
 Ordnance to have cannon of 15-inch calibre made for the purpose. 
 
 The bureau and myself represented to the department that there were 
 strong reasons against this selection at the time, viz : A 15-inch gun must 
 weigh between 40,000 and 50,000 pounds. Only one of the kind had 
 been made, and its endurance tested, but with inferior charges. Our most 
 experienced founders were therefore not practiced in the fabrication of 
 such heavy cannon, nor, indeed; of cannon larger than the 11-inch, about 
 one-third as heavy as the 15-inch. The accidental rupture of a 15-inch 
 on board a monitor when in action would disable and might be fatal to 
 the vessel. 
 
 There was no time for deliberate experiment, the exigency of the coun- 
 try demanding immediate decision. A gun of smaller calibre, say 13-inch, 
 would be more reliable, and its shot of 280 pounds, driven with greater 
 charges, would exercise destructive eifect on any plates which the rebels 
 could oppose to our fire. In addition to which the lesser dimensions of 
 the 13-inch would admit of its being fired outside of the turret. * 
 
 * I can say now, after repeated experience in battle with these guns, and the various results 
 derived from them, in other ways, that myjopinions, already stated as submitted to the Navy 
 Department, have undergone no change ; the complications inseparable from firing inside or 
 outside would alone have constituted sufficient objection to the J 5-inch if they had been as 
 well understood as they are now ; and I believe that the question of a suitable cannon for 
 monitors is still open for decision at some future day. 
 
126 
 
 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 The department adhered to its selection, and it became the duty of the 
 bureau to carry its directions into execution j the responsibility of drafting 
 the gun was devolved on ine. 
 
 The engagement between the monitor and the rebel ram took place on 
 the 9th of March, 1862. On the 17th the department ordered the bureau 
 to provide 20 15-inch guns and 10 20-inch, for the monitors to be 
 built. On the 20th the bureau telegraphed an order to the Fort Pitt 
 foundry for the casting of 15-inch guns, and on the 6th of April I had 
 completed the draft of the navy 15-inch gun. 
 
 There was only one foundry in the country prepared to enter immedi- 
 ately upon the fabrication of cannon of such weight. The bureau had, 
 therefore, no choice of terms, first in order and importance of which was 
 the trial of a gun to extreme proof ; but the founders were not willing to 
 submit to other proof than that ordinarily required by the army ordnance 
 for each gun, viz : the firing of three rounds with 50 pounds and a shell, 
 and intimated that they would suspend the fabrication until these views 
 were assented to. 
 
 An appeal was made by the bureau to other foundries, with the follow- 
 ing result : 
 
 Date. 
 
 July 11,1862. 
 Aug. 20, 18 . 
 
 Aug. 20, 186-2. 
 Aug. 20, 1^62. 
 
 Aug. 20, 18'" 2 
 Aug. 20,18 2 
 Aug. 20, isr.2. 
 
 Names. 
 
 Foundry. 
 
 R. P. Parrott | West Point . 
 
 Z. Chafee j Providence - . 
 
 Juo. Sparrow Portland Co. 
 
 Mathews & Moore . . . . j Philadelphia 
 
 ' 
 
 Hinkley & Williams.. j Boston...' 
 
 Seyfert & McManus..| Reading 
 
 A er ^ Co . . Boston . . 
 
 Reply. 
 
 July 18, 1862. Declined for the 
 present. 
 
 August 28,1852. Will accept 
 conditionally. * 
 
 August 26, 1862. Declined. 
 
 August 30, 1862. Indefinite ; de- 
 pends upon how many are 
 wanted. 
 
 August 23, 1862. Not prepared. 
 
 August 21, 1862. Accepted. 
 
 September 19,1862. Insufficient 
 facilities, &c. 
 
 The Reading foundry alone accepted; but as no immediate deliveries 
 could be expected from it for the use of the monitors, (none did take 
 place until April, 1865,) the bureau had no alternative but to submit to 
 the terms of the Pittsbtirg foundry, and these, as already stated, there- 
 fore constituted the " basis of acceptance" for the 15 -inch guns then 
 under contract, which the bureau was obliged under the circumstances 
 to consent to. 
 
 But to guard the public interests against the calamity of accident in 
 a monitor, the first 15-inch gun was ordered to be fired 50 more rounds 
 at the proving ground, and then sent to Washington for extreme test. 
 
 With all the despatch that the founders could use the first naval 15-inch 
 was not ready when the first monitor (Passaic) had been launched and 
 required her armament, (30th September.) 
 
 When the second 15-inch had been completed and mounted in the 
 Passaic (October 20,) the proof of the first gun had advanced to 220 
 fires. 
 
 It now became evident that two 15-inch guns could not be supplied to 
 any of the monitors then being finished, and hence an 11-inch was asso- 
 ciated with a '15-inch in each turret. 
 
 With this armament the first squadron of monitors went through the 
 active service of the co-operative campaign against the defences of 
 Charleston, in 1863. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 127 
 
 When all the circumstances are considered under which the naval 
 bureau of ordnance accomplished this task, the extreme and immediate 
 necessities of the Union cause for iron-clads, the unprecedented size of 
 the 15-inch guns, the absence of all the customary data and experiments 
 whereby the bureau could guide its action, the fatal injury to the Union 
 cause if even a single gun of those placed in the monitors should give 
 way in any battle I say when all these are considered, it will be con- 
 ceded that no ordnance authority had ever been submitted to a like respon- 
 sibility, nor received less credit for the judicious and successful manner 
 in which it acquitted itself of that duty to the country in those years of 
 sore need, 1861, 1862. 
 
 THE 15-INCH G-UN. 
 
 The basis of acceptance for this gun for use in turrets was its estab- 
 lished character in the service, and the tests to which it had been submit- 
 ted to that end, viz: One trial gun burst in July, 1855, and another 
 April 18, 1856. 
 
 RIFLE 150-POUNDER. 
 I 
 
 This gun was brought into the navy under circumstances as exigent 
 and extraordinary as the 15-inch, with even less substantial data to pro- 
 ceed on. 
 
 So far as such heavy rifled calibres were concerned, the bureau had 
 scarcely a well-assured fact for its guidance at a time when the towering 
 strides of the rebellion were tasking the utmost efforts of the Union gov- 
 ernment, and demands beset it on all hands for these very cannon. 
 
 Just before 1 took charge of the naval bureau of ordnance, in July, 
 1862, my predecessor apprised the Navy Department (July 10, 1862) that 
 
 The investigations on the subject for rifled cannon had hardly commenced at the breaking 
 out of the rebellion. 
 
 The imperative call for rifled guns from all the officers commanding vessels in the block- 
 ading squadrons, and the rapid increase of the navy, obliged the bureau, as the department is 
 well aware, to make use of every reliable expedient to meet the demand. It has not been 
 possible, under the circumstances, to conduct experiments with the view to improvement in 
 the deliberate manner which has characterized every important change in our naval ordnance. 
 
 It may be proper to state, in this connection, that the ordnance author- 
 ities of other countries were then in no better plight than ourselves in 
 this respect. 
 
 The Parrott 100-pounder may be said to date from the 28th of October, 
 1861, as it was then brought to the consideration of the Bureau of Ord- 
 nance, as the tiles show that the first gun of that class had been taken 
 to Sandy Hook for trial, and that another would be deliverable in a 
 week. 
 
 In March, 1862, the first 8-inch rifle (which is the piece used in tur- 
 rets) was in condition for experimental test when it was fired 50 times. 
 
 Under the necessity of a pressure more inexorable than any Ordnance 
 Bureau had ever before to sustain, Captain Harwood, then chief of bureau, 
 ordered two guns of this class for service, (April 12, 1862.) 
 
 There was no time to await the course of deliberate and full experi- 
 ment, and the bureau was compelled to commit the rifled 8-inch to the 
 tests of service with such desultory and imperfect trials as the exigency 
 permitted, and these must be considered to constitute the only basin of 
 acceptance for the 8-inch rifle that was possible. 
 
128 
 
 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 Reply to query 3. 
 
 The extreme proof to which the test naval 15-inch gun was put may 
 be given as follows, viz : 
 
 Mammoth powder 
 
 Cannon powder. 
 
 80 rounds of 30-pound shell of 330 pounds. 
 20 rounds of 35-pound shell of 330 pounds . 
 70 rounds of 40-pound shell of 330 pounds. 
 22 rounds of 45-pound shell of 330 pounds. 
 1 round of 50-pound cored shot of 400 pounds 
 49 rounds of 50-pound shell of 330 pounds. 
 
 242 
 
 20 rounds of 30-pound shell of 330 pounds. 
 
 377 rounds of 35-pound shell of 330 pounds. 
 
 4 rounds of 35-pound cored shot 400 pounds. 
 
 20 rounds of 40 -pound shell of 330 pounds. 
 
 1 round of 49-pound cored shot 400 pounds. 
 
 27 rounds of 45-pound shell of 330 pounds. 
 
 1 round of 45-pound shot of 427 pounds. 
 
 101 rounds of 50-pound shell ot 339 pounds. 
 
 1 round of 50-pound canister of 208 pounds. 
 
 20 rounds of 55-pound shell of 330 pounds. 
 
 21 rounds of 60-pound shell of 330 pounds. 
 2(5 rounds of 60-pound cored shot 400 pounds. 
 
 3 rounds of 60-pound solid shot 430 pounds. 
 
 2 rounds of 65-pound cored shot 400 pounds. 
 2 rounds of 70-pound cored shot 400 pounds. 
 
 626 
 242 
 
 Total 868 
 
 I 
 
 . The above is the report rendered January, 1869, upon a call 
 from the bureau to correct discrepancies in former reports. 
 
 It is to be observed that the mammoth powder is inferior in strength 
 to the cannon powder used by the navy in all heavy guns. 
 
 The exact relation of strength cannot be given now for want of pre- 
 cise data. 
 
 I directed some practice for range in order to obtain an approxima- 
 tion for the information of the committee $ it resulted that the mammoth 
 powder gave only 960 (average) yards from a 9-inch gun at an elevation 
 of 3 27', whereas the range with the standard powder gave 1,325 yards. 
 Besides this greatly decreased power, the ranges were very irregular ; 
 extreme difference 209 yards, showing irregularity of action in the pow- 
 der. It is to be remarked, however, that the powder had undergone . 
 some handling, and perhaps exposure. Other powder, of undoubted 
 quality, will be obtained and tried. 
 
 The practice for range was resorted to, as the ballistic pendulum hap- 
 pened at the time to be temporarily out of adjustment. 
 
 The ordinary proof of the first 34 15-inch cannon, to make them 
 receivable from the founder, was the army-proof required by Mr. Knap, 
 viz : three charges of 50 pounds of powder (mammoth) and one shell of 
 315 pounds. In addition, before mounting in service, the bureau ordered 
 25 rounds of service charges, viz: 30 pounds powder (ordinary) and one 
 shell of 330 pounds to be fired. 
 
 The ordinary proof fixed for the last 66 15-inch guns was three fires 
 with 35 pounds and shell ; three with 45 pounds and shell ; and three 
 with 55 pounds and cored shot of 400 pounds. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 129 
 
 THE 11-INCH GUN. 
 
 The first 11-inch gun was fired 1,959 times, when it burst, viz 
 506 times with shell of 132 pounds. 
 655 times with shot of 170 pounds. 
 798 times with shell of 132 pounds. 
 
 1,959 
 
 The charge was in all cases the service charge of 15 pounds, except in 
 nine instances with 10 pounds, and seven times with 5 pounds. 
 
 This gun manifested an extraordinary quality of metal ; it began to 
 exhibit cracks about the chamber early in the proof; these extended 
 gradually from the chamber into the bore, and at the 1,958th fire the 
 crack extended from the inside to the outside, showing a length of 24 
 inches on the outer surface, from the vicinity of the vent forward along 
 the cylinder ; but the gun remained whole, and I deferred the last charge 
 until Mr. Alger, who cast the gun, could witness this singular instance 
 of tenacity. The gun was then loaded again and burst into three pieces; 
 the line of fracture separating the body of the gun lengthwise, and the 
 chase breaking off outside the trunnions. 
 
 THE 8-INCH 150-POUNDER. 
 
 The proof gun of this class was fired 420 times, when it burst, viz : 
 
 Sehenkl, (shot,) 50 rounds, 194 J pounds, ") 
 
 Parrott, (shot,) 21 rounds, 172 pounds, ! charges, 15 pounds navy 
 
 Schenkl, (shot,) 263 rounds, 194J pounds, [ powder. 
 
 Hotchkiss, (shot,) . 86 rounds, 199 J pounds, J 
 
 420 
 
 It is due to Mr. Parrott to say that he complained of the use of other 
 shot in his gun than those for which he designed it, and that he had 
 protested against the use of any other, (November 14, 1862 ;) also that 
 his term for the gun was " 8-inch rifle, 77 and that in speaking of it as a 
 200-pounder, he only conformed to the nomenclature of the ordnance 
 department. (See article 390, page 102.) 
 
 On the other hand, the bureau considered that the use of different 
 shot might be compulsory or desirable ; and it was therefore its policy 
 to know the capacity of the gun to endure such as were in common use. 
 
 However, taking into consideration the points presented by Mr. Par- 
 rott, it was plain that the gun would have endured longer with 150 -pound 
 shot than with shot of 200-pounds ; it might be also that the Parrott 
 shot would strain the gun less than other shot. 
 
 The endurance, therefore, of the 8-inch rifle was to be accepted at a 
 higher rate than 420 fires, and conformably to the preference of Mr. Par- 
 rott the weight of shot was fixed at 150 pounds, and the gun was (by 
 general order) named an 8-inch 150-pounder rifle. 
 
 The ordinary proof of each 8-inch rifle of this class has been 10 rounds 
 with 16 pounds of powder and a shell of 139 pounds. 
 
 Reply to query 4. 
 
 I am not aware that any calibre used by the navy has been adopted 
 from the tests, proofs, or experiments of the army ordnance by the naval 
 Rep. No. 266 9 
 
130 EXPERIMENTS ON HEAVY OEDNANCE. 
 
 
 
 bureau of ordnance, excepting that of the 15-inch, and then in that case 
 the responsibility, model, and design of the gun were placed upon myself 
 and were made to conform to those of the 9-inch and 11-inch guns of the 
 navy, except in length, which was reduced so as to suit the limited space 
 of the monitor turrets where they were to be placed. 
 
 The only essential particular in which the army experience was con- 
 sulted was the mode of casting the 15-inch 5 and it is easy to see that 
 under the circumstances this was unavoidable. 15-inch guns had been 
 ordered by the Navy Department for the monitors then building ; the 
 foundry where the first 15-inch had been cast-, being the only one capable 
 of such work at the time, had received the order to cast the navy 15 inch, 
 and the proprietors of the foundry were also proprietors in part of the 
 patent for hollow casting; there was no time to ascertain by trial what 
 treatment of iron was proper for such unusual masses of metal if cast 
 solid, and the only gun of the kind that had been made was cast hollow. 
 I believed that the public interests required me to use the same means 
 that had been adopted for the trial 15-inch gun for the army even at the 
 cost of some strain on my own convictions. I did not hesitate, there- 
 fore, at the seeming sacrifice of these convictions, with the express res- 
 ervation, however, that the hollow casting should be used no longer than 
 the occurrence of the opportunity to investigate the other method fully 
 by experiment. 
 
 On the other hand, in reply to the second branch of the question, the 
 army ordnance is infinitely more indebted to the navy for the principle 
 of the present model, on which its heavy cannon are now constructed. 
 This is contested I know; it is denied by General Rodman that the 
 models of the army cannon are similar to those of mine, and in this he 
 is supported by other officers of the army, as the committee may observe 
 from the opinions already in testimony before them. (See report of 
 heavy ordnance, February 13, 1365; testimony of Generals Ramsey, 
 page 9, and Barry, page 51 ; Captain Mordecai, page 56 ; and Mr. Knap, 
 page 85.) 
 
 But there are other officers of the army who do not agree that the 
 models are different, viz: Captain Benet of the army ordnance says, 
 page 37: 
 
 The outline of both guns is pretty much the same. 
 
 Colonel Benton of the army ordnance says, page 69 : 
 
 I do not think there is any essential difference, however, in the two forms. 
 
 (Another part of his testimony is not entirely consistent with this.) 
 Besides, Mr. Parrott says, page 144: 
 
 I believe Captain Dahlgren thinks the army have taken the models of his guns, as the 
 columbiads are made essentially as the Dahlgrens were. 
 
 I am not alone, therefore, in my opinion as expressed above, and am 
 convinced that the plainest judgment will recognize the entire similarity 
 of model by placing draughts of the army guns alongside of mine ; and if 
 to these be added the draughts of the old models those which the hollow 
 casting failed to make reliable I think the judgment will be assisted by 
 the comparison. 
 
 No other instance of importance occurs to me just now where either 
 bureau has been indebted to the other in the way referred to by the 
 query of the committee ; nor would such be likely to arise often, in view 
 of the very different applications of ordnance which are made by the 
 army and navy, and the great dissimilarity of conditions to which each 
 is subject. 
 
 The requirements of sea and land service differ too widely to admit of 
 there being much in common in the choice of artillery and its appliances. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 131 
 
 The business of both bureaus makes cannon their specialty; but 
 while light artillery is an essential constituent of a military organization, 
 it is a mere incident to naval operations, employed only in boats or 
 where small bodies of seamen are landed, and has no part whatever in 
 the legitimate purposes of a navy that is, ship against ship. 
 
 On the other hand the heavy cannon is the true almost the exclu- 
 sive weapon of a ship of war employed in her proper business, singly 
 or in fleets, while the campaign of a long war may be carried on with- 
 out firing a shot of heavy calibre. 
 
 During the war of the rebellion I am not aware that the army ever 
 fired a shot in action from a 15-inch gun ; and even 10-inch guns and 8-inch 
 rifles were sparingly used, while the heavy cannon of the navy resounded 
 along the Mississippi and the Atlantic shores from the batteries of Far- 
 ragut and Porter, Foote and Dupont, and were echoed back from the 
 British channel by the 11-inch guns of the Kearsarge. 
 
 I have no idea of saying that the army have no use for heavy cannon, 
 but that as a general rule such use will not be frequent. 
 
 Again, the conditions under which heavy cannon are to be used ashore 
 or afloat, very widely and essentially influence their weight, dimensions, 
 and appliances. 
 
 The gun which is to be used in a fort may be as heavy and as long as 
 may be deemed best for its efficacy. Not so in a ship ; the weight of 
 cannon is regulated by the capacity of the vessel to carry, or of its 
 decks to bear ; and the length by the space that is available ; (particu- 
 larly was this experienced in the 15-inch guns for the monitors.) Some- 
 times these conditions may conflict ; there may not be space for all the 
 guns a ship can carry, nor capacity to carry where there is abundant 
 space. Then there is the problem of armament in pivot or in broadside. 
 Who can decide such questions, or discuss them, but men experienced as 
 seamen and as ordnance officers? It could hardly be the province of a 
 soldier. 
 
 Quite as much special nautical aptitude is needed to determine the 
 carriages for sea artillery. Ashore the handling and pointing of a heavy 
 gun where the platform is fixed and space abundant, is comparatively a 
 small matter to the accomplishment of a like purpose on shipboard, where 
 every kind of motion is to be provided against. 
 
 A great difference of construction at the breech also occurs between 
 heavy cannon for forts and for ships, occasioned by the use of breech- 
 ings for the guns of the latter, which are never used in the cannon 
 mounted on fortifications. 
 
 And who, if not a sea officer, shall decide on the kind of gun carriage 
 to be used in boats, or for landing from boats, and subsequently ashore? 
 
 On the other hand, how shall a naval officer possess himself of the 
 information and experience to fit and equip the peculiar appliances of 
 field artillery, the carriages, caissons, horses, harness, all the multifari- 
 ous details of that splendid arm ? 
 
 It would not be possible to unite in any corps of men from the army or 
 from the navy the knowledge and experience necessary to conduct the 
 ordnance business of both, from the design and fabrication of cannon 
 and its accessories through all the details for service. 
 
 The results obtained in England and France from a consolidated 
 organization offer us nothing that should tempt us to an imitation of 
 their example. 
 
 The British organization, unable to keep pace with the feverish appre- 
 hension of the public, was subjected to an entire change. The direction 
 was taken from the regular authorities and handed over almost in fee 
 
132 EXPEEIMENTS ON HEAVY ORDNANCE. 
 
 simple to the autocratic control of a scientific civilian, one of the most 
 accomplished engineers in England ; he was rewarded in advance with 
 knighthood and a princely gift. What was the result? After several 
 years of untrammelled effort and the expenditure of $15,000,000, (in gold,) 
 all the heavy Armstrongs were altered or dismissed from service, ashore 
 and afloat, the inventor's plans exploded and himself unseated. Eng- 
 land cannot to this day feel sure that she is in possession of a heavy 
 rifled cannon that is to be relied on. 
 
 France is believed to be no happier in the results of her ordnance 
 department and I think I have seen in service the most recent of them. 
 
 Reply to query 5. 
 
 I am at a loss to reply to this query as the committee may intend that 
 I should. To do so completely, in the broadest sense, would require the 
 examination of a large quantity of reports and correspondence accumu- 
 lated from the commencement of the rebellion, which will include by far 
 the greatest number of 9-inch and 11- inch cannon now in the navy, all 
 of the 15-inch cannon, all of the rifle cannon of heavy calibre, and all 
 wrought-iron guns submitted to inspection or received. This has been 
 commenced, but at this date I have accomplished but a small part of the 
 task. 
 
 With the permission of the committee, I will therefore reply in a briefer 
 manner, which may perhaps meet the purposes of the committee. As 
 regards cast-iron guns, the least crack, external or internal, would cause 
 immediate rejection at sight ; therefore no founder would knowingly ever 
 offer such a gun for inspection. Cavities occurring in the bore or cham- 
 bers of cannon will cause their rejection on sight, and on the outside 
 also if they exceed certain dimensions. As a sample of the exact adher- 
 ence to terms required of founders who have contracted to make cast- 
 iron cannon for the navy, and of their ready compliance therewith, I give 
 the following extract from the record, viz : 
 
 11-inch, Reading foundry, November 10, 1862. Not proved. After bor- 
 ing and while turning an indentation or defect discovered having the 
 appearance of a slight scratch. On probing it, the unsound part extended 
 to the depth of T 3 ^ inch less than the prescribed dimensions. Caused by 
 the inferior quality of the sand, having a tendency to swell under the 
 heat. Gun rejected. Location of defect, upper part of chase forward of 
 lock lugs. 
 
 Two guns, 11-inch, Reading foundry, November 16, 1862. Not proved; 
 same defect from same cause as above. Guns thrown aside by contractors. 
 
 It is due to the contractors to say that they have rarely complained 
 of the exact nature of the inspection and the losses to which it subjected 
 them. No appeal from their bargain has ever been made or thought of 
 by them. 
 
 Besides cracks of this kind, the hollow-cast guns seem to be liable to 
 others peculiar to themselves, though I am not able to say whether these 
 casualties are of frequent occurrence. The record notes the following: 
 
 15-inch, No. 404, Reading foundry, army gun. Burst open nearly the 
 entire length of the gun, while in the heading lathe, with a loud explo- 
 sion equal to the report of a 6-pounder. 
 
 15-inch, No. 419, Reading foundry, army gun. Burst in the pit after 
 removal of core barrel, and while cooling the bore with water conducted 
 through it at the rate of 18 gallons per minute. 
 
 15-inch, (no number,.* Fort Pitt foundry, navy gun. The inspector in 
 his weekly report states that one 15-inch gun cast on the 6th instant 
 has been condemned by the founders, the gun having burst while cooling. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 
 
 133 
 
 Reply to query 6. 
 
 To answer this would require sufficient time to collect the facts from a 
 record largely accumulated during the rebellion, which the conveniences 
 of the committee does not permit. It would include every cast-iron gun 
 which was proved or fired so far as to exhibit cracks or signs of rupture, 
 and was then permitted to remain in that condition without being burst. 
 I will therefore reply as well as I can to this query in a general way. 
 
 All fissures or cracks which appear inside or outside after firing will 
 cause the rejection of any cast-iron cannon. Interior cracks may appear 
 in cast-iron cannon, and will often continue to extend for a large number 
 of rounds before bursting, provided the metal is of the least respectable 
 endurance ; the line of rupture will also in such cases take the same 
 general direction, at least in the present models. But when the metal of 
 the gun has been very bad originally, or has been rendered so by im- 
 proper treatment, or by bad model, and has no endurance, the gun will 
 break up in fragments after very little firing. 
 
 The experience with heavy wrought-iron cannon is not sufficient to 
 define the law of fractures occurring in such material ; it may be that 
 cavities, cracks, or even fissures, do not imply a liability to rupture as 
 imminent or dangerous as in cast iron. But it requires much experiment 
 to determine to what extent these defects may extend without rendering 
 the gun unserviceable. 
 
 Wrought-iron cannon, like that on the Princeton, for example, have 
 burst as suddenly and as fatally as guns of cast iron, and others have 
 endured severe tests after the appearance and extension of cracks in the 
 bore. 
 
 The same may be said of some cast-iron guns. The first 11-inch gun 
 withstood 1,000 rounds after it began to crack inside; and the crack pene- 
 trated entirely to the outer surface for a length of two feet in the rear 
 of the trunnions without breaking the gun open; the next fire however, 
 did so. 
 
 I have noted in replies to other questions of the committee some 
 information which might be repeated here, and to which I beg leave to 
 refer. This reply is very incomplete, owing to the want of time to scruti- 
 nize the reports of firing and inspection of wrought and cast guns. 
 
 Reply to query 7. 
 
 1827. The regulations of this year for naval ordnance, " adopted by 
 the board of navy commissioners," Commodore Bainbridge, president, 
 prescribe the following for proof of the heaviest cannon by powder: 
 
 
 Weight 
 of gun. 
 
 Proof 
 charges. 
 
 
 42-pounder heavy 
 
 Cwt. 
 7U 
 
 Pounds. 
 21 
 
 ) Equal to one-half 
 
 32-pounder heavy 
 
 60 
 
 16 
 
 > the weight of 
 
 24-pounder heavy 
 
 49 
 
 12 
 
 N solid shot. 
 
 
 
 
 
 Each gun was to be fired twice with these charges, and two shot with 
 three wads, one being placed over the powder, another over the first shot, 
 and another over the second shot. 
 
 If, after this proof, any defect appears which occasions doubt of safety 
 for general service, this proof is to be repeated. 
 
134 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 1845. The next instructions concerning proof of "cannon are found in 
 the ordnance regulations of 1845, when an entire reorganization of 
 ordnance was adopted, adopting one calibre for all shot guns that of 32 
 and fixing three classes of shell guns, a notice of which will be found in 
 my work on " Shells and Shell Guns." 
 
 In these the Bureau of Ordnance received discretion to have a 9- 
 pounder cast as a model gun, which was to be proved as follows : 
 
 No of rounds 20 j powder 3 pounds ; shot, 1, &c., &c., &c., until the 
 gun breaks. 
 
 The proof charges of the heaviest guns were : 
 
 
 
 Powder. 
 
 Shot. 
 
 10-inch 10 000 pounds 
 
 Pounds. 
 
 18 
 
 1 
 
 8-inch 10,000 pounds 
 
 18 
 
 2 
 
 8-inch of 63 hundred -wei ght . . ... . 
 
 18 
 
 1 
 
 8-inch of 53 hundred- wei ght . ... t 
 
 14 
 
 1 
 
 32-pounder of 61 hundred-weight 
 
 16 
 
 2 
 
 32-pounder of 57 hundred- weight . 
 
 15 
 
 2 
 
 
 
 
 Each gun to be fired twice. 
 
 If one gun in every ten failed to sustain this proof, the remainder 
 were to be fired again with the same charge and one shot, if two had 
 been used before, and with three-fourths the charge if only one shot had 
 been used before. 
 
 If one gun in nine failed to stand this proof, all that had been proved 
 were to be rejected. 
 
 The board included Morris, Warrington, Crane, Wadsworth, and 
 Shubrick. 
 
 It is presumed that this was the usage is 1850. 
 
 In 1852 a more elaborate series of ordnance instructions was promul- 
 gated by the bureau. 
 
 In these the chief of bureau "may, if lie thinks proper, have a trial 
 gun cast therefrom* which shall be subjected to such proof as he may 
 direct and specify in the contract." 
 
 The proofs were to be : 
 
 
 Powder. 
 
 Shot. 
 
 10-inch of 10 000 pounds 
 
 Pounds. 
 
 18 
 
 1 
 
 8-inch of 63 hundred-weight 
 
 16 
 
 ] 
 
 8-inch of 55 hundred- weight . . 
 
 14 
 
 1 
 
 64- pounder of 106 hundred- weight .. ... 
 
 20 
 
 2 
 
 32-pounder of 6J hundred-weight 
 
 16 
 
 2 
 
 32-pounder of 57 hundred-weight 
 
 15 
 
 2 
 
 
 
 
 Each gun to be fired twice. 
 
 First. It will be observed that it still remained discretionary with 
 the chief of bureau to order a trial gun or not. 
 
 Second. That he was restricted in kind or size as before. 
 
 Third. That the proof of the 8-inch of 6,300 pounds was reduced from 
 18 pounds to 16 pounds 5 that the 8-inch of 10,000 pounds disappeared 
 and was replaced by the heavy 64-pounder, (an 8-inch cannon,) of 10,600. 
 
 *Iron offered by contractors. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 135 
 
 It is to be supposed that this continued to be the proof in 1855. 
 
 The officers of the board were, Farragut, Dornin, Barren, Harwood, 
 Fairfax Commodore Morris, chief of bureau. 
 
 In 1860 the ordnance instructions were revised. No directions are 
 given in regard to the inspection and proof of cannon. 
 
 The 9-inch, 10-inch, and 11-inch of my design are there announced as 
 part of the regular armament. 
 
 The officers of the board were, Goldsborough, Harwood, Lee, and Fair- 
 fax Captain In graham, chief of bureau. 
 
 1864. First. The instructions of this date give discretion to the bureau 
 before contract, to order a trial gun for extreme proof with service charge. 
 This gun was to serve as a standard for metal to be used. 
 
 Second. "But whether a trial gun was made or not," the chief of 
 bureau might select "for extreme proof with service charges," one out of 
 any lot of guns offered under contract. 
 
 Third. Proof charges : Fifteen-inch, No. 1, 50 pounds, cored shot ; No. 
 10, 35 pounds, shell. 
 
 Eleven-inch, No. 1, 25 pounds, shot ; No. 10, 15 pounds, shell. 
 
 Ten-inch, No. 1, 18 pounds, shot ; No. 10, 12 pounds, shell. 
 
 Nine-inch, No. 1, 15 pounds, shot ; No. 10, 10 pounds, shell. 
 
 Eight-inch, 6,300 pounds, No. 1, 12 pounds, shot j No. 10, 10 pounds, 
 shell. 
 
 One-hundred-and-thirty-pounder of 16,000 pounds, No. 10, 30 pounds, 
 one shot. 
 
 Sixty-four-pounder of 10,600 pounds, No. 10, 20 pounds, one shot. 
 
 Thirty- two-pounder of 5,700 pounds, No. 10, 15 pounds, one shot. 
 
 If five per cent, out of any lot offered for ordinary proof under a con- 
 tract shall fail to sustain it, the whole may be rejected, as may be stipu- 
 lated in the contract. These, it is presumed, were the rules in 1865. 
 
 1866. The instructions of this year fix the proof charges as follows : 
 
 Fifteen-inch, No. 3, 35 pounds, shell ; No. 3, 45 pounds, shell ; No. 3, 
 55 pounds, cored shot. 
 
 As in 1864, the failure of five per cent, in a lot gave discretion to reject 
 all. The instructions of each date are to be accepted as a recognition of 
 the operations and practice then adopted. 
 
 The practice of proving cannon by increased charges of powder and 
 shot prevailed prior to 1827, and continued to 1845, with the addition, at 
 the latter date, of a trial gun of 9 pounds calibre, proved previously by 
 specified charges 5 and this was the only improvement on the previous 
 system $ and this was not enjoined, but was discretionary. 
 
 1852. In 1852 the trial gun was still retained as discretionary with the 
 bureau, and no calibre being assigned, that too thus became discretion- 
 ary also, so that he was empowered to have the trial gun of any calibre, 
 and to prove it in any way he thought proper. 
 
 I860. In the instructions of 1860 all mention of proof or inspection is 
 omitted. Important changes had taken place. Our new screw frigates 
 and sloops were armed, according to my own system, with Dahlgren 
 9-inch, 10-inch, and 11-inch guns, and these guns are given in the instruc- 
 tions as of regulation. In fact, with these, other views of proof had come. 
 
 I had always been opposed to the principle of proving any gun with 
 more than a service charge. The proof gun was always to be one of the 
 kind to be proved, and its proof was to be service charges till burst. 
 
 The ordinary proof for each gun might be a small number of service 
 charges, 10 or 20, but the bureau still retained a large number of guns of 
 the old system in service, and hesitated to apply my views to it ; so 
 nothing was said, which may be the explanation. 
 
136 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 1864. This year my own views are accepted. The bureau was author- 
 ized to use a trial gun to fix the standard, and also to select a gun from 
 a lot for extreme proof, with service charges. 
 
 In addition, as the question of hammering plating was presented, and 
 the guns were to use higher charges, therefore the ordinary proof added 
 one service charge of that description. 
 
 1866. The same is retained, except with 15-inch guns. 
 
 The proof to extreme, being at the discretion of the bureau, has been 
 fixed at 1,000 rounds (service) in the contracts. 
 
 Reply to query 8. 
 
 It would be impossible for me to answer this question fully and cor- 
 rectly within the very limited time which the convenience of the com- 
 mittee permits, as it would necessitate the close examination of a large 
 number of log-books, besides the numerous records of this bureau. 
 
 I will only be able to submit a few desultory and disconnected facts, 
 premising that they are insufficient to form a proper opinion. 
 
 When the first 15-inch gun was being put through a course of proof- 
 firing I was absent, or too closely occupied with other duties to be present. 
 The record is very general, noting only the principal facts. 
 
 While in command of the South Atlantic squadron I was frequently 
 on board the monitors in action, and therefore witnessed the general 
 character of the firing, but my attention was always too closely taken up 
 by passing events to time the rate of fire. The impressions on my mem- 
 ory are that it required five to six minutes for each shot from a 15-inch 
 gun, and this is all that I can say with reference to the rapidity of fire 
 that was attained in action by 15 inch guns of monitors, mounted on the 
 carriages in their turrets, the machinery of which was worked by hand. 
 
 In the spring of 1868 a 15-inch gun was tried upon a carriage worked 
 by steam, after the design of Mr. Eads. The most rapid fire was the 
 discharge of 12 shot in 16 minutes, making an average interval of one 
 minute and 20 seconds between the fires, which is certainly an excellent 
 result ; one interval was as small as 58 seconds. Still it cannot be com- 
 pared with the result of ordinary fire in action cited previously, because 
 there was a very essential difference in the circumstances. 
 
 When fired ^irom the monitor turret the 15-inch gun was not only 
 loaded, but the turret was revolved from the object, then back upon the 
 object, to which it had to be adjusted by one person who did not see the 
 object, but received direction from another who did see it, yet very imper- 
 fectly, through a tube at the side, and was also delayed by the swaying 
 of the vessel, whether at anchor or under way ; all of which, under the 
 most favorable circumstances, would occupy at least half of the five or 
 six minutes. 
 
 On the other hand, the interval of one minute and 20 seconds, accom- 
 plished by the steam apparatus and carriage, only denoted the time 
 required to load and fire ; the carriage was placed on a scow ; the gun 
 horizontal, and not pointed. 
 
 The difference between firing in service and in experiment is also con- 
 siderable, even where circumstances are otherwise similar. On one occa- 
 sion a 9-inch gun was fired from the experimental battery four times, 
 with an average interval of 53 seconds ; least, 45 seconds. On another 
 a 9 : inch gun of the experimental battery was fired six times ; average 
 interval, 38J seconds ; the least, 32 seconds. In another instance in exper- 
 iment, an 11-inch gun was worked by eight men and fired twice, the 
 interval being 61 seconds. But this rate of fire with such cannon would 
 not be possible in action. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 
 
 137 
 
 On the whole, I have no doubt the 15-inch gun can be fired more 
 rapidly on the steam carriage than on one worked by hand, but what 
 that difference is, how far to be relied on with certainty, and at what 
 cost in other advantages, experiment alone will show, and should be made 
 to show. 
 
 Reply to query 9. 
 
 The navy has never used a Parrott 10-inch rifle. I have no informa- 
 tion as to the rapidity of fire with Parrott 8-inch rifles. In general, more 
 time is required to load a rifle-cannon of large calibre than a smooth-bore, 
 the weights of shot and charge being alike. 
 
 Reply to query 10. 
 
 All the information upon this subject that can be reached within the 
 time admissible to prepare this paper has been given in the reply to 
 query 8. 
 
 Reply to query 11. 
 
 THE NAVY 15-INCH GUN. 
 
 There being two classes of the navy 15-inch gun the short and the 
 long and a large proportion of the original cannon made after my 
 draught having been altered, the question of the committee will be best 
 answered perhaps in the following way: 
 
 The navy 15-inch guns may be classed thus : 1. The original 15-inch 
 designed by myself. 2. Guns of the same class, subsequently altered by 
 order of the bureau. 3. The new model 15-inch, got up by direction 
 of the bureau. 
 
 The original navy 15-inch was designed by myself, and, conformably to 
 the wishes of Captain Ericsson, was restricted to such length as would 
 permit it to be fired inside the turret. 
 
 Thirty-four guns were made in accordance with this design, one-half 
 of which were subsequently increased in the chamber and decreased 
 outside at the chase by order of the bureau. 
 
 Of the 16 15-inch which were not altered but remained as designed 
 by me, the service of two is only known to have been very good, one 
 having been lost in the Weehawken, and the other sold from the Lehigh. 
 
 The remaining 14, with the proof gun, endured 3,152 fires, averaging 
 210 rounds, the greatest being (No. 1) 622, and the next 529. 
 
 Of the 17 15-inch guns, made after my design and not altered therefrom, 
 the proof gun was burst by 868 charges, and three were injured prema- 
 turely by service firing, viz : 
 
 ORIGINAL 15-INCH, (SHORT.) 
 
 No. 
 
 Rounds fired. 
 
 On board. 
 
 'Condition 
 
 . 
 
 19 
 
 132 
 
 Onondasra - ...... .... 
 
 Cracks at vent. 
 
 
 13 
 
 Unknown 
 
 Lehigrh . 
 
 Muzzle cracked, 
 
 (sold.) 
 
 14 
 
 96 
 
 Onondaga 
 
 Cracks at vent. 
 
 
 
 
 
 
 
 Seventeen other 15-inch guns of my model were altered by the bureau 
 by reaming out the chamber and reducing the chase. They have been 
 fired in all 2,266 times, averaging 135 fires, the greatest being (No. 34) 
 363 fires, and the next (No. 23) 358 ; both are reported to be in doubtful 
 condition. 
 
138 
 
 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 Of the whole number, eight have been more or less injured by firing, 
 as follows, viz : 
 
 No. 
 
 No. of fires. 
 
 On board. 
 
 Condition. 
 
 19 
 
 351 
 
 
 Reports contradictory. 
 
 0^ 
 
 358 
 
 Cauonicus 
 
 Reports contradictory. 
 
 *M 
 
 168 
 
 Monadnock 
 
 Excessive wear (sold ) 
 
 05 
 
 9 
 
 Sold at auction 
 
 Cracks at vent 
 
 k >6 
 
 9 
 
 Sold at auction ................. .... 
 
 Cavities in chamber. 
 
 07 
 
 161 
 
 Monadnock . ..... . ... 
 
 Condemned, (sold.) 
 
 oq 
 
 243 
 
 Sauo*us 
 
 Burst at chase Fort Fisher. 
 
 31 
 
 363 
 
 
 Doubtful 
 
 
 
 
 
 As a memorandum before your committee has given the reasons for 
 altering my design of the navy 15-inch gun, I presume it is admissible 
 for me to examine how far these reasons are sustained by the evidence 
 given. 
 
 The memorandum says, (Heavy Ordnance, page 129,) that 
 
 It was found necessary to reduce the opening of the ports in the turrets as much as possi- 
 ble, and to permit the muz/le of the gun to protrude through them, thus doing 1 away with 
 the troublesome smoke-box hitherto used, and which was indispensable with the shortened 
 15-inch gun originally designed. 
 
 During this dilemma it also became apparent, from repeated results with the " teat cham- 
 ber," that it was not only most inconvenient in service, but it really hastened the rupture of 
 the gun instead of preventing it. 
 
 It thus became necessary to act, and promptly too. 
 
 Therefore the present Chief of the Ordnance Bureau ad interim directed the first 15-inch 
 cast for the navy, and which was then undergoing a series of experimental firing at the ord- 
 nance yard, in this city, to be placed upon the lathe, the teat chamber reamed out, so as to 
 leave a chamber nearly parabolic in form, and to reduce the diameter of the chase and muz- 
 zle to correspond with that of the model of the 13-inch gun. 
 
 The result was most satisfactory; the gun enduring heavy charges of 50, 60, and two of 
 70 pounds of ordinary cannon powder, with shells and shot, the latter weighing 440 pounds, 
 and did not give way until it had reached nearly 900 rounds. 
 
 The order was immediately given to rechamber and turn down in the same way all the 
 original 15-ineh guns, and to cast, as soon as possible, a lot of these guns on the new pat- 
 tern. 
 
 Now the facts of the case may be summed thus : 
 
 1st. The first 15-inch gun, as I designed it, was fired 622 times, with 
 charges varying from 30 pounds of mammoth powder to 50 pounds of 
 cannon powder. 
 
 2d. After this the teat chamber and vent were reported to show only the 
 usual wear. 
 
 3d. The teat chamber was then reamed out to a parabolic form by order 
 of the bureau, and the extremity of the chase reduced in diameter to 
 that of a 13-inch gun. 
 
 4th. The firing was resumed and carried to 246 rounds, with charges 
 varying from 45 pounds of mammoth to 70 pounds of cannon. At the 
 246th fire the gun burst. (See reply to query 3.) 
 
 The Ordnance Bureau deemed this result so satisfactory that it ordered 
 all the 15-inch guns at hand to be reamed out and reduced as the proof 
 gun had been. 
 
 Was this action of the bureau in altering the 15-inch warranted by 
 the facts of the case f 
 
 The bureau makes its reasons for altering the model to rest on the 
 premise that the teat chamber hastened the rupture of the gun. 
 
 Now does this appear to have been justified when the teat chamber 
 was perfectly sound after 622 fires, and no sign was then perceived indi- 
 cating rupture, or even weakness ? 
 
EXPERIMENTS ON HEAVY ORDNANCE. 139 
 
 If either chamber is chargeable with the hastening the rupture of the 
 gun it must have been the parabolic, for with that the gun gave way 
 after 246 rounds. 
 
 The true conclusion after 622 fires was that a gun which endured so 
 well ought not to have been altered at all, but should have been tested 
 to the end in its original construction, and no "change was warranted 
 even in the other guns that had been cast, unless the extreme proof of 
 another gun of the class had shown better endurance, and there was 
 sufficient reason to believe this to be due to the alteration that had been 
 adopted, whether in chamber or elsewhere. 
 
 Is not this view fully sustained by the subsequent results with these 
 15-inch guns, altered and unaltered I Of the 17 on the original model 
 only three were unserviceable after firing 3,152 rounds. Of the 17 that 
 were altered, eight were unserviceable after firing 2,296 rounds. 
 
 To my mind there is but one conclusion possible : my original design 
 was not improved by the alteration made by order of the bureau, in the guns 
 that were cast, but was injured thereby. 
 
 Let us now consider the other question which forced itself upon the 
 consideration of the authorities. The memorandum says : 
 
 It was found necessary to reduce the opening of the m ports in the turrets as much as possible, 
 and to permit the muzzle of the gun to protrude through them, &c. 
 
 The reading of this does not seem to express what it really intends, 
 which I understand to be, the firing from the inside of the turret was 
 found to be so troublesome in service by reason of the smoke box, which 
 was indispensable to the practice, as to make it necessary to pass the 
 gun through the turret 5 but as the chase-diameter of the 15-inch 
 would require too large an aperture for this purpose, it was reduced, and 
 the original model was altered, increasing the length of the gun, and 
 reducing the diameter of the chase to that of a 13-inch gun, by which 
 improvement the thickness at muzzle was reduced from the original five 
 and three-quarter inches to three inches ; very little more than one-half 
 of what I considered necessary for the incidents of service. There were 
 66 15-inch guns cast upon this pattern. The first gun was chosen for 
 proof; it endured 131 fires, after which Commander Breese reported it 
 to be doubtful. Of the remaining 65, 42 have been fired only the proof 
 rounds, now fixed at nine. Twenty-five have been mounted in iron- 
 clads, and been subjected to such firing as the course of service required, 
 amounting to a total of 1,333 fires ; making an average of 53 fires for 
 each gun ; greatest number (No. 43) 236 fires j (No. 37) 206 fires. Of 
 these 25, four have been injured, viz : 
 
 No. 
 
 No. of 
 rounds. 
 
 Where fired. 
 
 Condition. 
 
 35 
 
 131 
 
 Proof . . 
 
 Doubtful 
 
 44 
 
 85 
 
 Mahopac . ...... ....... 
 
 Ohase split 
 
 67 
 
 102 
 
 Puritan. - 
 
 Cracks about vent, (sold.) 
 
 68 
 
 59 
 
 Trial of carriage 
 
 Cracks about vent (sold. ) 
 
 
 
 
 
 So that the original model lost only one-fifth of its number after its 
 17 guns had been fired 3,152 times. 
 
 An equal number of original guns, after being altered, lost nearly one- 
 half their number, though fired but three-fourths as often as the same 
 number of original guns. 
 
 The new model (long 15 -inch) lost one-fourth of its number, or nearly 
 an equal proportion as the original model, though only subjected to two- 
 fifths the firing, (less than one-half.) 
 
140 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 The foregoing statements show that the substitution of a new cham- 
 ber, and a reduction of the chase, in the original guns were detrimental 
 to the strength of the guns ; they also show that the new model was not 
 to be trusted in service. 
 
 All the difficulties noted in the foregoing arose from pursuing a wrong- 
 direction in the first instance. 
 
 The department was advised that under existing circumstances a 
 smaller calibre than that of 15-inch was prefer able, and that of 13-inch 
 was suggested. The 15-inch was, however, adhered to, and the first 
 consequence was to be met at the threshold; the chase diameters of the 
 15-inch were so great that it was found inadmissable to open a point in 
 the side of the turret sufficiently large to admit of the muzzle passing 
 outside. 
 
 To obviate this it was necessary to abut the muzzle on the inner sur- 
 face of the turret, and to .make an aperture in the turret only large 
 enough for the passage of the ball. 
 
 The first firing showed that the smoke would not be endurable when 
 the gun was fired in this way ; the muzzle was therefore boxed, which 
 proved effective ; but it was soon found that the box was liable to give 
 way continually before the great concussion of firing, even with the very 
 moderates charge used. 
 
 The inside firing had therefore to be abandoned, and a port opened, 
 but to make this possible the chase diameter must be reduced ; and so, 
 instead of falling back on a proper calibre, the size of which would not 
 require too large a port for firing outside, it was determined to reduce 
 the chase of the 15-inch. 
 
 This resulted in altering the guns of original model, and in the casting 
 of others upon a new model ; the consequences of which have been 
 shown to be highly injurious to the endurance of these 15-inch guns, 
 if not absolutely destructive of their reliability. 
 
 The memorandum argues against the adoption of the 13-inch gun, 
 (page 131,) from the failure of those tried, the want of time for experi- 
 ment, the necessity of firing outside, &c. 
 
 1st. Whatever were the defects of the inside firing, it was well estab- 
 lished by the long-continued service off Charleston that it could be con- 
 tinued in any further service for which the monitors might be required. 
 
 If therefore the 15-inch was to be adhered to, it was better to fire 
 inside and to take the chances of the smoke-box than to reduce the chase 
 to an untrustworthy diameter. 
 
 2d. There was quite as much time to correct errors in the founding of 
 13-inch as there was to experiment with the 15-inch, which the altera- ' 
 tions really amounted to. 
 
 These errors were obvious, and needed only correcting, not experiment. It 
 has been a primary principle in making cast-iron cannon that the larger 
 the cannon the less was the probability (I might say the certainty) of its 
 endurance. Therefore if a 15-inch gun could be made strong enough 
 for service, a smaller gun like the 13-inch would be much more so, and a 
 contrary result proved errors in the fabrication, the models being alike. 
 
 The data cited by the memorandum point to this, and even with an 
 error that exists in these data they should be conclusive ; for instance, 
 the memorandum states that one of these 13-inch " did not give way at 
 500 rounds." 
 
 Kow the entire actual service of the 15-inch shows that only one gun 
 of this kind was fired more than 360 times, and that one gun went as far 
 as 529 fires ; perhaps in no case did the charges exceed 35 pounds of 
 powder, while the 13-inch was fired with charges of 50 pounds. It is 
 
EXPERIMENTS ON HEAVY ORDNANCE. 141 
 
 further to be remarked that these 13-inch guns were made at a foundry 
 which for the first time essayed the process of hollow casting, and could 
 hardly be expected to attain entire success at the outset. 
 
 It seems to me that there was every assurance in this single result to 
 show that 13-inch guns cast with as much care and experience as the 
 15-inch, would have more endurance than the 15-inch, while the size of 
 the chase would need no greater size of port than was actually given to 
 the reduced 15-inch. This course risked far less than that pursued by 
 the bureau, which was an experiment against probabilities. 
 
 The memorandum also goes beyond the question of calibres with its 
 incidents, and enters upon the question of solid and hollow casting, 
 taking for its premises certain data, which, even correctly given, would 
 not, I think, lead to the conclusions of the memorandum, because the 
 foundry at Providence was entirely without experience in casting cannon 
 of any size, and its results were, therefore, not to be compared with those 
 of another foundry, where the experience of years had been accumulated 
 under special directions. 
 
 On the contrary, I will affirm, from my own long experience, that the 
 result at Providence was eminently successful. To make a solid casting 
 of a 13-inch gun so well the first time that it stood 178 fires, is to me an 
 assurance of entire success with more experience ; but an important error 
 is made by the memorandum in stating that the 13-inch gun cast at 
 Pittsburg was cast solid. It was cast hollow, and with all the lights of 
 a long experience, yet it gave way at 108 fires. 
 
 Shall we infer from these facts that a 13-inch gun could not be made 
 as endurable as a 15-inch, the processes and the models being alike ? 
 
 Shall we infer that the experienced founders at Pittsburg could only 
 make a hollow-cast 13-inch to stand 108 fires, when foundries inexpe- 
 rienced in hollow casting could make a 13-inch, also hollow-cast, that 
 would not burst at 500 fires ? 
 
 Shall we infer that the Pittsburg gun, cast after the hollow method so 
 highly extolled,* (page 88, Heavy Ordnance,) would only endure 108 
 fires, when another of like model cast solid, by a founder who had never 
 done such work before, would only burst at 178 fires ? Certainly not ; 
 yet these would be the inferences, from the premises given and corrected, 
 of the memorandum. 
 
 On the whole I am unable to perceive that it was advisable first, to 
 select the 15-inch for the monitors ; secondj to alter it, as was done, when 
 it had been chosen ; and I think first, that the 13-inch gun was prefer- 
 able because it could have been made more enduring than the 15-inch 
 was, not too large to permit its being fired outside, and had sufficient 
 power (50 pounds and shot of 280 pounds) to penetrate any plating 
 opposed to us by the rebel rams ; second, that when the probable incon- 
 venience of the 15-inch had been realized in service, the reasons for sub- 
 stituting the 13-inch became imperative, instead of retaining the 15-inch 
 and lessening such usefulness as it may have possessed by alteration. 
 
 * Mr. Knap said: 
 
 I would say, as my opinion as a manufacturer, and from my examination of these guns, that there is not 
 known any method of procuring the same efficiency at the same cost and the same risk to life of your own 
 men, as the heavy ordnance cabt upon the Rodman principle. You may take a cast-iron gun or wrought-iron 
 gun, or anything else of very heavy calibre, and I will be willing to haug my gun alongside of it and let them, 
 be fired, aud if mine fails before the others do I will give up. 
 
142 
 
 EXPEEIMENTS ON HEAVY ORDNANCE. 
 
 PARROTT RIFLE GUNS DISABLED. 
 
 Calibre. 
 
 Register 
 number. 
 
 Vessel. 
 
 Remarks. 
 
 100-pound er 
 
 2 
 
 Hunchback 
 
 Burst 23 inches from muzzle June 19, 
 
 Do 
 
 4 
 
 Westfield 
 
 4864. 
 Burst at breech and opened band in 
 
 Do 
 
 6 
 
 Mahaska 
 
 several places, October 31, 1862. 
 Thirty-six inches of muzzle burst off; 
 
 Do 
 
 11 
 
 Commodore Barney... 
 
 date unknown. 
 Muzzle burst off; shell exploded in 
 
 Do 
 
 18 
 
 Genesee 
 
 gun, April JO, 1862. 
 Cracked in rear of bouching May, 1864. 
 
 Do 
 
 21 
 
 Cimarron 
 
 Burst 2"<i-J inches from muzzle Feb- 
 
 Do. 
 
 24 
 
 Paul Jones ...... 
 
 ruary 15, 1864. 
 Burst, fracture from trunnion, to rear 
 
 Do 
 
 05 
 
 Sassacus 
 
 of band, July 18, 1863. 
 Cracked ; two cracks at vent Janu- 
 
 Do 
 
 29 
 
 Juniata ..... 
 
 ary, 1865. 
 Burst ; rear part flew out, December 
 
 Do 
 
 44 
 
 Commodore Perry 
 
 25, 1864. 
 Burst at breech June 17 1864 
 
 Do 
 
 135 
 
 Fort Jackson 
 
 Cracked at vent January 14, 1865. 
 
 Do 
 
 137 
 
 Quaker City 
 
 Burst two and a half feet of muzzle off, 
 
 Do 
 
 141 
 
 Mackinaw ....... 
 
 December 24, 18(54. 
 Burst ; breech blown out, December 
 
 Do 
 
 149 
 
 Commodore Read 
 
 26, 1864. 
 Cracked in top of bore and around 
 
 Do 
 
 150 
 
 Commodore Read. 
 
 breech, November 14, 1864. 
 Cracked at bouching, November 14, 
 
 
 
 Naugatuck . 
 
 1864. 
 
 Burst. 
 
 Do 
 
 162 
 
 Ticonderoga. ..... 
 
 Burst at muzzle, November 14, 1864. 
 
 Do 
 
 166 
 
 Yautic . 
 
 Burst ; breech blown out, December 
 
 Do 
 
 194 
 
 Maumee 
 
 24, 1864. 
 Cracked through vent January 1865. 
 
 Do 
 
 213 
 
 Kansas ... 
 
 Cracked at vent, December 24, 1864. 
 
 Do 
 
 233 
 
 Osceola 
 
 Cracked ; two cracks from band to 
 
 Do 
 
 238 
 
 Mendota ..... . 
 
 trunnion, January 15, 1865. 
 Cracked from trunnion to band, July 
 
 Do 
 
 262 
 
 Tallapoosa 
 
 24, 1864. 
 Muzzle blown off by premature explo- 
 
 Do 
 
 288 
 
 Mohican 
 
 sion of shell, April 5, 1865. 
 Burst, December, 1864. 
 
 Do 
 
 311 
 
 Ticonderoga 
 
 Burst into 10 pieces December 24 
 
 Do 
 
 325 
 
 Lenape 
 
 1864. 
 Cracked through vent Februarv 1865 
 
 Do 
 
 330 
 
 Lenape .... 
 
 Cracked through vent, February, 1865. 
 
 150-pounder 
 
 6 
 
 Patapsco 
 
 Slight crack at muzzle July 22, 1863 
 
 Do 
 
 28 
 
 Shenandoah 
 
 Crack in rear of vent extending around 
 
 Do... 
 
 46 
 
 Onondaga 
 
 breech, February, 1865. 
 Two cracks in bore. 
 
 Do 
 
 59 
 
 Pequot 
 
 Burst three feet ten inches from muzzle 
 
 Do 
 
 60 
 
 Colorado 
 
 September 12, 1864. 
 Seam from trunnion to band Decent- 
 
 Do 
 
 61 
 
 Onondaga 
 
 ber25, 1864. 
 Cracked at vent, April, 1865 
 
 Do 
 
 82 
 
 Susouehanna 
 
 Burst ; piece of muzzle blew out June 
 
 
 
 
 15, 1865. 
 
 TRIAL GUN AT CASTLE ISLAND, NOVEMBER, 1862. 
 
 Four hundred and twenty rounds; charges 15 pounds of powder. 
 Shot: Schenkl, 194 J pounds ; Parrott, 17?| pounds ; Hotchkiss, 199 J 
 pounds. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 143 
 
 WIARD'S 15-iNCH SMOOTH-BORE, (CAST IRON.) 
 
 The first and only gun fired of this description burst June 4, 1864, at 
 the first proof-fire ; charge 80 pounds of powder, and shot of 880 
 pounds. 
 
 ERICSSON 12-INCH SMOTH-BORE (WROUGHT IRON.) 
 
 The Ericsson (13-inch smooth-bore of wrought iron) was fired Octo- 
 ber, 1864, 40 times, viz : 
 
 Two charges of 30 pounds of powder, shot 280 pounds ; five charges 
 of 35 pounds of powder, shot 280 pounds ; five charges of 40 pounds of 
 powder, shot 280 pounds ; five charges of 35 pounds of powder, shot 280 
 pounds ; five charges of 50 pounds of powder, shot 280 pounds ; five 
 charges of 55 pounds of powder, shot 280 pounds ; five charges of 60 
 pounds of powder, shot 280 pounds ; two charges of 65 pounds of pow- 
 der, shot 280 pounds ; three charges of 70 pounds powder, shot 280 
 pounds ; three charges of 75 pounds powder, shot 280 pounds. Gun 
 unserviceable. 
 
 12-INCH RIFLES. 
 
 These were castings on the exterior form of 15-inch guns ; bored to 
 12-inch and rifled. The order was given August 31, 1863, by Captain 
 Wise, then chief of bureau. One of these was rifled on Mr. Parrottfs 
 plan, 'one on Atwater's, and one on Rodman's. 
 
 The 12-inch rifled on Mr. Parrott's method burst at the 27th fire, viz : 
 
 Five charges of 35 pounds of mammoth powder ; five charges of 40 
 pounds of mammoth powder ; five charges of 45 pounds of mammoth 
 powder ; five charges of 50 pounds of mammoth powder ; five charges 
 of 35 pounds of No. 7 cannon powder ; one charge of 40 pounds of No. 7 
 cannon powder ; three charges of 45 pounds of No. 7 cannon powder. 
 
 The 12-irich gun, rifled on General Rodman's method, was badly 
 cracked by 16 fires, viz : 
 
 Three charges of mammoth powder, 35 pounds; three charges of 
 mammoth powder, 40 pounds; four charges of mammoth powder, 45 
 pounds; four charges of mammoth powder, 50 pounds; one charge of 
 mammoth powder, 35 pounds; one charge of mammoth powder, 40 
 pounds. 
 
 Shot, 618 to 619 pounds. Gun cracked ; firing stopped. 
 
 The third 12-inch rifled, on Atwater's plan, burst at the 30th fire ; 
 generally 55-pound charges ; and shot varying from 416 to 535 pounds. 
 
 The practice was conducted at Fort Monroe by the army ordnance, 
 (1867.) 
 
 DAHLGREN 150-POUNDERS. 
 
 Only three of these were tested, and their accuracy was excellent, 
 but the iron was not of sufficient endurance, therefore never put into 
 service. One was burst in proof at the 27th fire ; one was fired 20 rounds ; 
 one was fired 75 rounds ; one was fired 60 rounds. 
 
 They remained unbroken ; but as I was not satisfied with the iron, 
 they were never put into service, and the pressing events of the war cut 
 short my connection with the subject. 
 
144 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 Reply to query 12. 
 
 The following 150-pounder cannon, and larger smooth-bore and rifled 
 guns, have been the subject of proof or experiment in the navy: 
 
 1. The 150-pounder Parrott ; the Dahlgren 150-pounder; the Bureau 
 600-pounder, (42-inch bore;) the Mann breech-loader, 8-inch; the Erics- 
 son 13-inch ; the Wiard 15-inch. 
 
 2. Of these the Parrott 150-pounder was adopted for the naval ser- 
 vice, but was subsequently laid aside on the recommendation of a board. 
 The proofs to which each has been subjected will be found in the replies 
 to previous queries. 
 
 The mode of proceeding in proof or experiment with these guns has 
 not been such, owing to the pressure of circumstances, as to furnish the 
 means of replying accurately in regard to the endurance of these rifled 
 cannon. 
 
 Some of the guns of different systems have exhibited endurance under 
 fire that would satisfy any requirement of naval service; and others of 
 the same kind have proved so inferior as to destroy confidence. 
 
 It must be kept in view that a uniform endurance with service charges 
 is the chief desideratum, even though it be moderate. This cannot be 
 supplied by the excessive endurance of some pieces if others fall very 
 low. 
 
 To the last paragraph of this interrogatory, I would say, that this 
 bureau is not cognizant of any rifled cannon of heavy calibre whose 
 admitted character would warrant its being adopted for the ordnance of 
 our navy. 
 
 A glance at the accounts from abroad do not show that in this respect 
 we are worse off than other naval powers. 
 
 England has been credited more than once with being on the eve of 
 solving the problem. But Armstrong and his coadjutors have passed off 
 the stage to make place for others who in the end may prove as unlucky 
 as himself. But a few days since we learnt that one of the present 
 favorite guns gave way, prematurely, to the great detriment of the rep- 
 utation of its class, as will be seen by the following extract from the 
 Army and Navy Journal of the 23d of January, 1869 : 
 
 Our London military contemporary informs us that the admiralty are alarmed at the explo- 
 sion of a Fraser gun at Woolwich. It says they have been in communication with the war 
 office, expressing their apprehensions on the subject of the large forgings in vogue at the 
 royal gun factories, though they have not gone as far as to repudiate the Fraser gun alto- 
 gether. Indeed, eight 10-inch guns have just been put on board the Hercules. 
 ######* 
 
 We can only regret (adds the Gazette) that the idea of a good gun seems as far off as ever, 
 meaning by a ' good," one which can be relied on with perfect security. 
 
 Of course we will some day have a rifle cannon equal to any require- 
 ment, but much time may elapse and more money will be spent before 
 that will happen. 
 
 GUN-BLOCKS. 
 
 At the commencement of the year 1868, a reply was forwarded to a 
 call of the committee for information in regard to iron castings for rifle 
 cannon that were to be finished at the Washington navy yard, which will 
 not be fully understood without further explanation, and I therefore ask 
 permission to supply this now very briefly. 
 
 The whole of this operation is to be considered as part of an effort by 
 the Bureau of Ordnance to meet the deficiencies of the navy in rifle can- 
 
EXPERIMENTS ON HEAVY ORDNANCE. 145 
 
 non, under circumstances too urgent to permit of the least delay. It 
 cannot therefore be tried by any of the ordinary conditions of peaceable 
 times. 
 
 When the rebellion broke out, in April, 1861, by the attack on Fort 
 Sumter, the navy was the least prepared to exert the power which the 
 extreme need of the country demanded. Among other deficiencies it 
 was without a single rifle cannon of heavy calibre. 
 
 The Bureau of Ordnance had for several years previous retarded the 
 investigation of this question, which I desired ; and, with the exception 
 of some rifle howitzers, to complete the boat armament, and a few iron 
 cannon for experiment, we had no rifle pieces for the naval service. 
 
 In view of the great emergency, it became the imperative duty of the 
 Bureau of Ordnance to resort to every expedient that held out the least 
 prospect of meeting the immediate necessity, and reluctant as I might 
 be to venture upon results with the scanty data at hand, particularly as 
 the great difficulty of the problem had staggered the ablest ordnance 
 men in other countries, yet I felt it incumbent on me to spare no effort 
 that would contribute to the common good, even if in so doing some 
 damage might be incurred to my professional reputation. 
 
 All the foundries and workshops of the north were being filled rapidly 
 with orders for the building of steam engines and the fabrication of can- 
 non for the army and navy ; so that it became expedient to call into 
 action the mechanical resources of the navy yard here, and in this way 
 the castings intended for rifled cannon, which could not be then finished 
 chiefly at the Pittsburg foundry, were brought to Washington for that 
 purpose. 
 
 It is not to be supposed that there was the same leisure for careful 
 scrutiny when the rebel flag was flaunted in sight of the capital that 
 there had been in the recent periods of peace. 
 
 The founders proceeded to make the castings rapidly, and as fast as 
 room occurred on the lathes of the navy yard, these were put under 
 process. 
 
 With all the haste that could be used, the first of these were not com- 
 pleted until the latter end of the year 1861, when the examination of the 
 iron and the test of firing were had. 
 
 I then became aware that the tensile strength and density were by no 
 means satisfactory, and drew the attention of the bureau to the proba- 
 bility of accident if this was not rectified. A little later I was led to 
 doubt if these castings were of cold-blast iron, and I recommended the 
 chief of bureau to withdraw all of them from service that were not cold- 
 blast, and to receive none that were warm-blast. 
 
 I may here remark that some difference of opinion exists in regard to 
 the necessity of cold-blast iron for cannon. It would consume too much 
 of the time of the committee for me to state the questions in detail, but 
 with a single exception I believe it may be said that experienced ord- 
 nance officers have insisted on cold-blast iron, while the founders con- 
 sider warm-blast good enough. It is certainly easier and cheaper, at 
 first cost, to make iron by warm-blast in smelting. 
 
 My own opinion, derived from no little experience in iron, always has 
 been in favor of cold-blast, even for smooth-bores. 
 
 As the examination proceeded, the lack in quality appeared in greater 
 degree. In two 50-pounders the density fell as low as 7.121 and 7.160. 
 In stating this to the bureau (26th April, 1862,) I remarked: 
 
 It would be hazardous to send into service guns of such low density. All the difficulties 
 which have been experienced with the 80-pounders and 150-pounders are entirely owing to 
 this and to other disqualifying causes, and I have already asked that blocks affording a 
 more suitable density might be sent here, but have not yet been furnished with them. 
 
 Rep. No. 266 10 
 
146 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 In this stage of the matter, the House of Bepresentatives asked for 
 information, and was answered by myself July 8, 1862; and by Captain 
 Harwood, the chief of bureau, July 10, 1862. 
 
 From my own reply, I extract the following : 
 
 The fabrication of rifled cannon may be said to have only begun in this yard with the 
 present struggle for the Union. 
 
 Little or nothing more was done between this and the period when Fort Sumter was 
 attacked. 
 
 Then the work of armament really began, and this department, so limited in its means, 
 and so little calculated to render any great assistance in the fabrication of cannon, was called 
 upon to contribute its quota, which has, I believe, been faithfully rendered. 
 
 The work has been conducted day and night, even while the flag of rebellion was flying 
 within sight, not omitting Sunday, for which I did not escape censure. 
 
 To this the bureau added, July 10, 1862 : 
 
 The investigations on the subject of rifle cannon had hardly commenced at the breaking 
 out of the rebellion, &c., &c. See page under head of (" Rifle 150-/Hwnrfer.") 
 
 The origin of the whole trouble lay entirely in the postponement of 
 the question by former chiefs of bureau. 
 
 In 1856 Captain Ingraham, then chief of bureau, would take no action 
 on my proposition to make a heavy rifled cannon, nor in 1857, when I 
 renewed it. 
 
 In 1859 I was allowed to make some experiments on a small scale, but 
 even this was arrested in January, 1860. 
 
 Permission to continue was yielded in October, 1860, when rebellion 
 stared us in the face. But it was too late; all the millions since spent 
 by the country would not buy back the years that had gone by unim- 
 proved, and we went into the conflict like a man picking up the first 
 weapon at hand. 
 
 The report of progress which I made in December, 1860, (already 
 given,) should have been possible four years previously, w^hen one cast- 
 ing after another, in due succession, would have afforded the means of 
 correction economically, instead of the wholesale trials of 1861, when 
 success was worth any cost, and which cannot therefore be tried by the 
 standard of peaceable times, but only by the desperate necessities of the 
 Union striving for existence. In view of which it became not the Bureau 
 of Ordnance nor myself to hesitate because some personal sacrifice was 
 demanded. 
 
 In conclusion, the material then procured is by no means useless, even 
 if it be unfit for rifled cannon ; the best of the castings may be made into 
 smooth-bores, and the balance used for other purposes. 
 
 CONCLUSION. 
 
 The queries of the committee were received by me on the 25th Decem- 
 ber, and it was my desire to reply to them in the fullest manner; the 
 brief period that remained of the session would not permit me, however, 
 to do more than is presented in the foregoing. 
 
 I trust it will have the consideration of the committee that my direct 
 connection with the Bureau of Ordnance ceased some five years ago, and 
 was only resumed a few months since ; that I was absent from the United 
 States during the greater part of this period, in command, successively, 
 of two of our squadrons. My knowledge, therefore, of much of the matter 
 that forms the subject of the committee's inquiry was unavoidably to be 
 derived or renewed from a scrutiny of the records of this office accumu- 
 lating since 1861, amounting (as reported to me) to more than 700 file- 
 books of letters, correspondence, reports, inspections, &c. 
 
 The committee may conceive that it was impossible for me to do this 
 myself or to have it done with entire exactness in the time at niy dis- 
 
EXPERIMENTS ON HEAVY ORDNANCE. 147 
 
 posal. I hope, however, that the purposes of the committee may be suffi- 
 ciently met by further explanation in any respect that the committee 
 may indicate. 
 
 With the permission of the committee, I beg leave to note in conclu- 
 sion 
 
 1. That when the rebellion began in 1861, the experimental investiga- 
 tion of the rifled cannon problem had gone no further than the rifled 
 howitzer for boats, (entirely successful,) and some of lighter iron calibres 
 the progress having been delayed previously (1856 and 1857) by the 
 decision of the chief of the bureau. 
 
 2. As a consequence the navy was destitute of any system of heavy 
 rifled cannon that was entitled to reliance when the rebellion broke out, 
 and it became necessary to meet the incessant and general demand for 
 these guns by supplying for immediate use whatever was procurable and 
 offered the prospect of even temporary usefulness; and thus it was that 
 the course of investigation which belonged to the experimental ground 
 was unavoidably transferred to actual service, with the certainty of 
 increased cost and at the risk of life; there was no help for it. It does 
 not appear that any other course was open to the naval bureau. It was 
 well, indeed, that under such trying circumstances the navy had a sure reli- 
 ance on the most powerful smooth-bores then ~known. 
 
 The results are before the committee; unsatisfactory, it is true, but 
 not more so than those of foreign navies, attained in peaceable times, 
 with every advantage of careful and costly experiment. 
 
 The attention of the committee has already been drawn (reply to query 
 12) to the reported failure of one of the successors of the Armstrong 
 system, which had swept away the long established ordnance of Eng- 
 land, and was in its turn put aside as unreliable. This later favorite 
 seemed to fulfil the promise of hopes long deferred, and now comes its 
 probable condemnation. 
 
 An armament of new breech-loading, heavy rifled cannon, which I 
 recently saw on board one of the latest French iron-clads, has, I am told 
 by a naval officer just returned from Europe, lately disappointed expec- 
 tation by the bursting of one of the kind in a ship of the squadron of 
 evolution. 
 
 We have now the opportunity of guarding the future against a recur- 
 rence of the losses and failures experienced in the late struggle by resort- 
 ing to careful experiment, the most sure of success at the least cost. 
 
 The difficulty of the question has been much ameliorated by the changes 
 of views which have occurred in regard to the uses of rifled cannon since 
 the opening of the rebellion. 
 
 Then all opinion, professional or public, placed no dependence on cannon 
 that were not rifled; the utmost anxiety was manifested to displace the 
 smooth-bores and substitute rifled cannon. Had it been possible nothing 
 else would have appeared in our ships, so extravagant were the expec- 
 tations that prevailed of their power. 
 
 Yery different are the views now entertained. The experience of battle 
 in the use of both kinds of ordnance has restored the confidence in smooth- 
 bores, not only for their certain and safe endurance, but for their power 
 and their accuracy within any range that earnest men are likely to try 
 issues on the ocean. It has been shown that the true role of rifled 
 cannon afloat is very limited, and that its numbers on shipboard will 
 therefore be proportionally few. 
 
 I can offer no bette revidence in this respect than the views of Vice- 
 
148 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 Admiral Porter, whose great experience in severe action will not fail to 
 receive due weight. He says : 
 
 The gun which I deem best adapted to the general use in the navy is the 11 -inch gun, 
 which can be carried on board even our smallest vessels, worked in a sea-way if the vessels 
 are properly constructed, and almost as rapidly as a 32-pounder ; at all events rapidly enough 
 for all practical purposes. 
 
 I consider its accuracy much greater than any rifle gun or any gun of a smaller calibre. 
 That, I believe, has been tested to the satisfaction of most navy officers. 1 am no advocate 
 for a large number of heavy rifled guns on board ship, although I think it does very well to 
 have a few combined with smooth-bores. I have no confidence in their accuracy at sea ; on 
 shore, where they are mounted on a good level platform, and where allowances can be made 
 for wind and weather, they will do very well, but on shipboard, where there is the least 
 motion, they fire very inaccurately. 
 
 If they should strike the w?.ter before reaching the object they are deflected at an angle of 
 45 and go wide of the mark. 
 
 That most important power, " ricochet firing," is entirely lost in the rifle guns, and in a 
 sea-way a vessel armed with ] 1-inch guns is, in my opinion, a match for a vessel with twice 
 the number of rifle guns. 
 
 I am not prejudiced against rifle guns from the fact that I have had a good many of them 
 burst, as I believe that most of those that burst were badly constructed, which I think is the 
 case with all banded guns. 
 
 I regret to say that I have seen many men killed and wounded by the bursting of 100- 
 pounder rifles, and many vessels injured. 
 
 The result of these accidents has been to impair the confidence of sailors in that class of 
 guns, and were I going to sea I would not have one on board. 
 
 I have never, to my knowledge, known an accident happen to the 9, 10, or 11-inch guns, 
 three of the best guns we have ever had in our navy ; and in battle men stand behind these 
 guns in perfect security, knowing that the chance of their bursting is very small. 
 
 I do not want you to suppose that I am an advocate for the abolition of rifle guns, for I 
 believe that excellent cannon of that kind can be made of cast-iron without banding. 
 
 What we need is a course of well-conducted experiment, carefully, 
 logically pursued by officers whose experience renders them cognizant of 
 all views of the question. 
 
 My report of 1862, as chief of bureau, shows that I then attained 
 results which should have led the way to further experiment and per- 
 haps to useful conclusions. It is to be regretted that these were not 
 pursued to that end. 
 
 The ample building at the navy yard, where I had hoped to examine 
 fully into the quality of different American iron, the modes of treatment 
 likely to insure the best metal, and to test the various models, has been 
 converted into a receptacle for unused and obsolete ordnance stores of 
 all kinds. 
 
 I feel that the committee can restore the operations of this bureau to 
 their true course, by recommending some moderate sum for experimental 
 purposes, and by separating the practical ordnance duties from the 
 merely administrative ; which is the more needed in the navy because 
 we have no distinct ordnance corps like the army, but trust to details of 
 officers from the line of service for carrying on every branch of naval 
 ordnance duty, from the inspection of cannon to fitting of ships at the 
 navy. yard. 
 
 For the convenient reference of the committee I annex a list of the 
 most recent chiefs of Ordnance Bureau : Captain Ingraham, March 10, 
 1856, to September, 23, 1860 ; Captain Magruder, September 24, 1860, 
 to April 23, 1861 ; Captain Harwood, April 24, 1861, to July 22, 1862 ; 
 Captain Dahlgren, July 22, 1862, to June 24, 1863 ; Captain Wise, June 
 27, 1863, to June 1, 1868; Rear- Admiral Dahlgren, July 22, 1868, to the 
 present date. 
 
 I have the honor to be, very respectfully, your obedient servant, 
 
 J. S. DAHLGKEN, 
 Rear-Admiral and Chief 'of Bureau. 
 
 FEBRUARY 11, 1869. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 149 
 
 APPENDIX C. 
 
 OFFICIAL REPORTS. 
 
 From the report of the Chief of Ordnance, Wavy Department, for 1861. 
 
 With reference to rifled cannon, for which there has been an unceasing 
 demand, the bureau, after mature consideration, decided that it would 
 be injudicious to rifle the old navy models, on account of their form not 
 being adapted to the severe strain to which rifled ordnance is subjected. 
 Another consideration which added force to this decision was, that in 
 the guns formerly made for the navy the treatment of the iron was dif- 
 ferent from that pursued in more recent years, and which is now deemed 
 to be a matter of paramount importance. 
 
 But to meet as near as was practicable pressing emergencies, the 
 bureau, after due investigation into the best description of this kind of 
 ordnance, selected that which was available, and which has been pro- 
 duced by the enterprise of private establishments. 
 
 Meanwhile the genius of Commander Dahlgren designed new models 
 for rifled cannon, which have been put in hand ; and now, with every 
 possible appliance of foundries and machine shops that are found avail- 
 able throughout the country, as well in the public works as in private 
 establishments, there is every reason to believe that, under any probable 
 contingency which may arise, the demand for ordnance will be promptly 
 supplied with cannon fully equal, if not superior, to any known to exist 
 at home or abroad. 
 
 From the report of the Chief of Ordnance, Navy Department, for 1862. 
 
 The constant and very natural solicitude manifested by the public in 
 the changes which have been and continue to be made in the construc- 
 tion and armament of our ships-of-war may warrant a more extended 
 notice of technical detail than might otherwise find place in a document 
 of this nature. 
 
 And yet no definite conclusion has been reached in regard to either of 
 these important problems. 
 
 Indeed, the most casual observer of current events can hardly fail to 
 
 perceive that neither of them has advanced beyond the first proposition. 
 
 * # * * * * * 
 
 The advantage of which is now apparent from the fact that our 9- 
 inch and 11-inch guns are found to be, in a measure, available against 
 iron-plating, because they will endure solid shot fired with one-half 
 greater,. and even double, the original charges. 
 
 So that we have the leisure to consider and devise any other species 
 of ordnance that may be better adapted to the purpose, and are not pre- 
 cipitated into hasty or questionable measures. 
 
 ******* 
 
 The ordnance expert can by no means rejoice in being free from diffi- 
 culties that puzzle his ingenuity. 
 
 The number of cannon being reduced to a third of the number he is 
 accustomed to rely upon, how shall he supply the loss of force by the 
 weight and kind of those which remain I 
 
 If he acquires power by greater weight, he loses by loss of time in 
 manipulation of gun and projectile ; hence some reduction by slowness of 
 repetition. Then, again, shall he use our smooth-bore, breech or muzzle- 
 loaders? Shall he pierce or crush and break bolts and strip off the 
 armor, or shall he even attempt to enter the interior with shells ? 
 
150 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 How economize the open space of the ports when the gun is out, or 
 close it when in ? 
 
 Leaving these queries to be answered by the parties most concerned, 
 it will suffice here to say that, just now, the offence has decidedly the 
 advantage, and no sea- going ship is considered to be so armored as to 
 be impregnable to artillery. Of the French results and inferences touch- 
 ing the several points we know nothing beyond what is necessarily dis- 
 closed to the observer in the construction of ships. 
 
 The British government have practiced less reticence ; and if we are 
 not permitted to become acquainted with the reasoning of their officials, 
 the results from which they do reason are so far public that one cannot 
 err very widely as to their general bearing. 
 
 A large number of witnesses have usually been present at the trials, 
 including officers, engineers, ship-builders, and others, civil and official. 
 The press is also well represented, and in a few days afterwards all the 
 proceedings are detailed minutely to the public, discussed in Parliament, 
 and in meetings where the ablest professional men are assembled for 
 the purpose. 
 
 So far as an opinion can be formed from such sources, one is led to 
 conclude that those who, from their distinguished abilities and oppor- 
 tunities of investigation, should be best qualified to judge, have arrived 
 at no final decision in regard to any of the essential points of the prob- 
 lem above stated, which is, indeed, reasonable, when it is noticed to 
 what extent these differ and even conflict. 
 
 About a year since (October 21, 1861) a number of eminent dignita- 
 ries, military, naval, and civil, met, in order to witness the trial of a 
 target representing the Warrior's sides. It was supposed that all the 
 power which ordnance could exert for such a purpose was brought into 
 play ; and after this had been done it seemed as if the witnesses were 
 generally favorably impressed with the endurance of the target, and 
 therefore of the Warrior. 
 
 But not long after (April 8, 1862) Sir William Armstrong placed in 
 front of this, or a similar target, a gun which he had just completed ; it 
 threw a round shot of 156 pounds, which, with 50 pounds of powder, 
 most unexpectedly changed the whole aspect of the question by its treat- 
 ment of the target, which was said to have been completely pierced. 
 
 The revulsion in common opinion went so far as to discredit the 
 Warrior entirely, and the fallibility of that vessel was pronounced certain. 
 
 But during a discussion in Parliament a member maintained that the 
 facts had not been accurately stated even by official authority, and the 
 deductions were consequently more unfavorable to the target than was 
 correct. He even affirmed that the target had not been fatally injured, 
 but would in fact have kept out the shot from entering a vessel. 
 
 Whether for this reason or not, the trial was repeated, and very fully 
 disposed of all doubts in favor of the target j but it settled the gun also, 
 which burst at the fourth round. 
 
 Thus demonstrating that if the target were penetrable by the fire of 
 such a piece of ordnance, it was only by an effort that destroyed the 
 gun also a risk not to be thought of on shipboard. 
 
 And hence it was inferred that the Warrior was impregnable to the 
 effort of any ordnance that could be then used safely against her. 
 
 The triumph of the defence was, however, of short duration ; for the 
 rupture of the Armstrong gun left the way open to other competitors, 
 and a long-neglected piece that had lain remote from view for several 
 years was suggested as deserving of an opportunity to try its powers. 
 
 This was the Horsfall 13-inch, of wrought iron. Its first blow, with a 
 
EXPERIMENTS ON HEAVY ORDNANCE. 151 
 
 shot of 280 pounds, was decisive. The plate was pierced and badly 
 injured, while the endurance of the gun was untouched. 
 
 As if to complete the entire failure of the defence, and to puzzle its 
 advocates, Mr. Whitworth undertook to drive a shell through a stout 
 iron-plated target, which he accomplished. 
 
 So that the system of armor that had been relied on was proven to be 
 vulnerable by shells, as well as by shot, which was an unhoped-for advan- 
 tage on the side of the attack. 
 
 Here it will probably rest for the while, until the defence shall be able 
 to devise some plan of greater efficacy. 
 
 It would be unwise, however, to rush to the conclusion that armor is 
 needless, because the most powerful ordnance should, under skilful 
 guidance, be able to pierce it. 
 
 For, even against such cannon, a ship may delay the final disaster 
 long enough to make its own guns of avail ; and when opposed to any 
 but these heaviest pieces, will still be in effect impregnable. 
 
 The case of the Monitor and Merrimack affords an illustration. 
 
 No one supposes that either of these vessels could have escaped serious 
 injury if subjected to a course of target-firing from the most recent and 
 powerful descriptions of ordnance, yet they sustained for four hours the 
 utmost effort of each other's batteries. 
 
 The Monitor was hardly more than scarred by the fire of the very 
 guns Avhich, on the preceding day, had in a fourth of the time acted most 
 destructively on the hulls and crews of two fine wooden frigates. 
 
 A very high official authority (Duke of Somerset, First Lord of the 
 Admiralty, House of Lords, April 3, 1862) has, to be sure, imputed the 
 default of injury to life or limb in this combat to a lack of power in the 
 artillery which the two vessels carried ; which is no doubt true ; but it 
 is equally true that no guns of like weight and kind now used in the 
 
 British navy would have effected as much under like circumstances. 
 
 * ***** 
 
 The operations that have been conducted here with reference to the 
 power of different cannon and projectiles, as well as the resistance of 
 iron plating, have been so far satisfactory that the results derived have 
 
 been consistent. 
 
 ******* 
 
 There must be, however, a material reduction in the celerity of fire 
 with guns and projectiles so large as the 15-inch, whatever may be the 
 mechanical appliances which may be brought to assist. 
 
 An 11-inch gun, with a well-disciplined crew, can be fired once a 
 minute ; but there must be much improvement in any mode now sug- 
 gested before a 15-inch gun can be fired once in thrice that time. 
 
 As a certain capacity for repetition is essential to the general power 
 of a battery, there is thus involved a disadvantage which can only be 
 compensated to any extent by the great concentration of effect in the 
 individual projectiles. For it may be conceived that the effects of shells 
 of 330 pounds, and shot of 450 pounds, will be damaging beyond any 
 experience in former battles. What may be the power of such ordnance 
 against iron-cased ships comparative or absolute remains to be ascer- 
 tained. This, as well as the piece itself, is yet but an experiment. 
 ****** 
 
 On another occasion an 11-inch gun was fired 500 times, of which 
 170 fires per day were made in two successive days, which so heated 
 the gun that it was found to be warm 18 hours afterwards. No sign 
 of weakness was detected. 
 
152 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 From the report of the Chief of Ordnance, N~avy Department, for 1863. 
 
 The only establishments in the country which were prepared for the 
 work of founding heavy cannon, when the rebellion took place, were the 
 South Boston, Fort Pitt, and West Point; the Tredegar Works at Eich- 
 mond, Virginia, having passed into the hands of the rebels. No govern- 
 ment establishment of the kind existed, and consequently the sole reli- 
 ance of both army and navy, at the commencement of our difficulties, 
 was upon these three foundries. 
 
 Eight nobly, however, did they come to the rescue in the hour of need, 
 and thus afforded time for the bureau to seek other manufacturers 
 who might be willing to undertake the work of supplying the navy with 
 cannon. 
 
 Although such operations are always attended with great risk to those 
 who were unaccustomed to the casting of heavy guns, it was not long 
 before several other establishments were ready to co-operate, and the 
 work of producing the guns of various calibres required was commenced, 
 
 and, I am happy to say, been most successfully prosecuted. 
 
 ****** 
 
 In procuring cannon for the navy the same conditions have been 
 exacted from all these foundries, as regards the character of metal and 
 every other element necessary to constitute good and reliable guns. 
 No gun has been accepted, as a standard, which has not been subjected 
 to the ordeal of 1,000 rounds of service charges. With this standard 
 thus established, all the guns of a contract must coincide in their com- 
 posite elements. 
 
 The only exception to this rule has been in the case of the 15-inch 
 guns cast upon the plan of Major Eodman, of the United States army. 
 Time did not permit of this proof being applied, and the guns were 
 necessarily accepted and put into service, after having endured, how- 
 ever, somewhat more than the tests prescribed by the army regulations. 
 
 It is most gratifying to know that the judgment of the Navy Depart- 
 ment has been sustained by the result of the further test which has been 
 applied to the first gun of this class made for the navy, and which is still 
 undergoing a series of experimental firing after being modified in form. 
 All doubt is thus removed of the ability of the Fort Pitt foundry to pro- 
 duce guns of this great size which can safely be relied upon ; and the 
 power thereby added to the fire of our monitors has been most fully 
 exemplified in the capture of the Atlanta. 
 
 Before dismissing this branch of its report, it is just that the bureau 
 should bear special testimony to the prompt and efficient manner in 
 which the West Point foundry has also done its share in supplying the 
 need of the service for a new style of ordnance. 
 
 The introduction of a few rifled guns of heavy calibre into the bat- 
 teries of ships had already taken place in foreign navies prior to the 
 date of our present rebellion ; and in our own service experiments were 
 being conducted at the Washington navy yard, under the direction of 
 Eear- Admiral Dahlgren, for the purpose of devising a system of rifled 
 ordnance. Nothing decisive, however, has been accomplished, except 
 with the rifled howitzer, and the experiments were rudely interrupted 
 in the spring of 1861. 
 
 At the same time Mr. Parrott was engaged in perfecting his present 
 system, and the results obtained by him were so satisfactory that in the 
 summer of 1862 the bureau, in conjunction with the army ordnance, 
 directed a 100-pounder to be subjected to a series of 1,000 service rounds. 
 
 The gun stood the test without bursting, and its accuracy and range 
 
EXPERIMENTS ON HEAVY ORDNANCE. 153 
 
 were considered sufficiently good to warrant the adoption of these rifled 
 guns as a permanent part of our naval armament. Since then the demand 
 for the several calibres has been unceasing ; and, as before stated, they 
 are to be found on board nearly every vessel now in service, and will 
 continue to be supplied until some better system is established. 
 
 Finally, from personal inspection, and witnessing the firing of over 100 
 rounds from these guns at the West Point foundry recently, the bureau 
 is satisfied that whenever attention is paid to details and even moderate 
 skill in the manner of loading and firing is attained, they will prove the 
 most serviceable rifled guns that have ever been introduced into any 
 service. 
 
 From the report of the Chief of Ordnance, War Department, for 1864. 
 
 The heavy gun of 20-inch calibre, for sea-coast fortifications, has been 
 successfully cast and finished, and a suitable carriage to mount it has 
 been prepared. It is now ready for experimental trials at Fort Hamil- 
 ton, in New York harbor, and the proper targets and other preparations 
 for testing its efficiency against the strongest war vessels, and ascertain- 
 ing the best manner of handling it in service, have been ordered to be 
 made. The results of these trials will demonstrate whether the expecta- 
 tions which theory warrants, of the destructive effects of this gun and 
 its value for defensive works covering narrow passes, are realized, and 
 whether such guns should be multiplied ; and if so, to what extent. If 
 they should establish the affirmative of this question, the cost of these 
 trials will be far outweighed by the advantages obtained from them ; 
 if otherwise, the loss will be insignificant in itself, and will probably be 
 a gain eventually, by preventing future experiments in the same line, 
 and settling the question of the largest effective calibre for sea-coast 
 cannon. 
 
 From the report of the Chief of Ordnance of the Navy Department for 1864. 
 
 COMPOSITION OF BATTERIES. 
 
 The governing rule in arming our ships of war has been to place on 
 board of them the very heaviest and most effective gun they can bear 
 with safety. 
 
 In general it may be stated, that the 9-inch are used for broadside; 
 the 10-inch, 11-inch, and the Parrott rifles in pivot ; the 15-inch for the mon- 
 itor turrets, and the bronze howitzers and rifles for boat and deck service 
 in shore. A few of our ships continue to be armed with the 32-pounder 
 and 8-inch guns of the old system 5 but these will probably give way to 
 the modified guns of similar classes above alluded to. 
 
 As no special changes have been made in the general arrangement of 
 batteries since my last report, the same vessels, mentioned therein as 
 types of their rates, may be again taken to illustrate the system of arma- 
 ment still in vogue. 
 
 Thus the battery of a first-rate is represented by the Minnesota 
 carrying 
 
 One 150-pounder rifled, ) . . , . 
 
 One 11-inch smooth, } m plvot > 
 
 Forty-two 9-inch smooth, ) . broadside 
 
 Four 100-pounders, rifled, } u le > 
 
 and four howitzers. 
 
154 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 Of a second-rate by the Brooklyn, carrying 
 Two 100-pounder rifled, in pivot; 
 Twenty 9-ineh smooth, ) . , /! 
 Two 60-pounder rifledj } ln broadside ' 
 and two howitzers. 
 
 Of a third-rate by the Eutaw, carrying 
 Two 100-pounder rifled, in pivot ; 
 Four 9-iuch smooth, } 
 
 Two 24-pounders, smooth, > in broadside. 
 Two 20-pounders, rifled, ) 
 
 Of the fourth-rate by the Owasco, carrying 
 
 One 11-inch smooth, ) . . , 
 
 One 20-pounder rifled, f u 
 
 Two 24-pounders, howitzers, in broadside. 
 And by the Nipsic, carrying 
 
 One 150-pounder rifle, ) . 
 
 One 30-pounder rifle, } m pivot 5 
 
 Two 9-inch smooth, in broadside, and four howitzers. 
 
 Of the monitors, by 
 
 The Tonawanda, four 15-inch; 
 The Onondaga, two 15-inch and two 150-pounders ; 
 And Montauk, one 15-inch and one 1 50-pounder. 
 Of the iron-plated gunboat of the western rivers, by the Carondelet, 
 carrying three 9-inch, four 8-inch, two 100-pounder rifles, one 50-pounder 
 rifle, one 30-pounder rifle. 
 
 The development of the power of each individual ship named as repre- 
 sentatives of the several rates is 
 
 In shot. In shells. 
 
 First rate 2,606 Ibs. 2,123 Ibs. 
 
 Second rate 1,220 990 
 
 Third rate 424 343 
 
 Fourth rate 210 183 
 
 And 294 255 
 
 In the monitors 
 
 Tonawanda 1,704 1,320 
 
 Onondaga 1,180 930 
 
 Montauk 606 465 
 
 In the western gunboat 
 
 Carondelet 588 - 480 
 
 It will be noticed that in each of the four rates of vessels above men- 
 tioned pivot guns are associated with those of broadside, so as to meet 
 more fully the necessity for long range at high elevations in chasing or 
 bombardment, and at the same time to maintain a direct fire without 
 materially altering the course of the vessel. The mechanical arrange- 
 ment of the pivot carriage also enables the mounting and working with 
 ease a much heavier gun than could possibly be handled on an ordinary 
 broadside carriage. 
 
 These pivot guns are always placed near the ends of the vessel, and 
 therefore do not interfere in the least with the working of the broadside. 
 The rapidity of fire from them is, of course, not so great as from an indi- 
 vidual gun of broadside, but is fully sufficient for the purpose of accuracy 
 at ranges beyond the reach of the lesser calibres. No ship can, there- 
 fore, be considered properly armed that has not a pivot gun of greater 
 
EXPERIMENTS ON HEAVY ORDNANCE. 155 
 
 power and range than the guns of broadside. But whether a battery, 
 consisting entirely of heavy pivot guns, would be more formidable than 
 one of broadside alone the aggregate weights being equal has not yet 
 been tried, the only effort of the kind being that of the Niagara, which 
 has a battery of twelve 150-pounder rifles mounted in pivot, and no regu- 
 lar broadside guns. 
 
 THE FOUNDRIES. 
 
 The number of these establishments engaged in the fabrication of can- 
 non for the navy has been reduced by one since the date of my last report, 
 the Portland Company having withdrawn from their contract. The 
 others have been fully employed in the work of keeping the navy sup- 
 plied with guns of unequalled strength and beauty of finish, from the 
 ponderous 15-inch to the light 32-pounder. No delay or embarrassment 
 has occurred in the delivery of the cannon contracted for, and the bureau 
 is more than ever assured of the reliability of the firms engaged in this 
 important business. 
 
 The Fort Pitt foundry, with its immense facilities and very great expe- 
 rience in the art of founding cannon, was at first the only establishment 
 able and willing to undertake the task of making the 15-inch guns. But 
 during the past year two other foundries the South Boston and the 
 Scott foundries, at Beading, Pennsylvania, having completed all the 
 arrangements necessary for the process of hollow casting have now 
 each a contract for this class of gun. No difficulty whatever is antici- 
 pated in the fabrication of these very large cannon, for the irons now 
 used by the respective foundries are known to be of the very best quality 
 for the purpose. The primary and most important element being thus 
 assured, the remainder of the task is entirely within the mechanical 
 ability of the foundries. 
 
 It is, therefore, no idle boast, that the cannon of the United States 
 navy, made exclusively from American irons, are unsurpassed by those 
 of any other nation ; and this will continue to be the case so long as the 
 enterprise of our citizens is left untrammelled, and full opportunities are 
 afforded for the exercise of their skill in this most important art. 
 
 Besides the 15-inch guns, the Fort Pitt, South Boston, and Reading 
 foundries are all engaged in making the other classes in use, including 
 also the new models of 8-inch and 32-pounders elsewhere alluded to. The 
 Builders' Iron Foundry, at Providence, Ehode Island, has just completed 
 a contract for 11-inch guns, and is now engaged on a new one for the 
 8-inch and 32-pounders; while the firm of Hinkley, Williams & Co. are 
 still engaged upon their contract for 11-inch guns. Thus the work has 
 been steadily prosecuted during the past year, and will be continued by 
 these foundries as fast as the demand for the smooth-bores increases. 
 
 The cast-iron banded rifles of Mr. Parrott, made at the West Point 
 foundry, are still the only kind used in the navy, except the bronze 12 
 and 20-pounders of Bear- Admiral Dahlgren. Since November of last 
 year there have been added to the stock of these rifles on hand at the 
 depots and in service 385 of the different calibres, including 20 new 60- 
 pounders, making a total at present available of 1,005 guns, after deduct- 
 ing 23 lost or disabled by the accidents of battle. Of these thus lost or 
 disabled, six gave way at the breech, four were broken by the explosion 
 of shells near the muzzle, three were cracked in the bodies, two were 
 condemned for excessive enlargement of vent, seven were lost by wreck, 
 and three captured by the rebels. The percentage of loss by rupture and 
 enlargement is therefore very small. 
 
 It may be remarked that no rifled gun has yet been devised which can 
 
156 EXPERIMENTS ON HEAVY OEDNANCE. 
 
 be considered perfect, and the bureau has sought in vain among the sys- 
 tems of European nations and the improvements of our own country for 
 a better gun, taken as a whole, than the Parrott rifle. Its lifetime, as 
 fixed by the inventor, is 750 rounds, but the navy guns have in many 
 instances shown a greater endurance. 
 
 It is true that reports are occasionally received of failures with the 
 Parrott projectiles, (also prepared at the West Point foundry,) but these 
 are again counterbalanced by the most favorable reports ; and it is cer- 
 tain that, whenever a close attention is paid to details in loading and 
 firing, these guns may be relied upon for range and accuracy. But if 
 these details from any cause are not sufficiently attended to, the firing 
 of no rifled gun can be considered safe or certain. At all events, what- 
 ever may be the defects of the Parrott system of rifled ordnance, no other 
 has yet been produced which commends itself so strongly to the service ; 
 and until another and a better one is devised and subjected to the same 
 ordeal, the bureau will continue to place its guns in the batteries of ships 
 as important auxiliaries to the smooth-bore pivots. 
 
 The condition of endurance is undoubtedly the first to be secured in 
 all guns, and no one expects to find this in as great a degree in the rifle 
 as in the smooth-bore. Hence the cast-iron gun of Mr. Parrott, although 
 strengthened by a spiral coil of wrought-iron around the locality of great- 
 est strain, is by no means to be expected to last as long under protracted 
 firing as a smooth-bore of the same calibre. But its probable strength 
 when carefully used, as all ordnance should be, is sufficiently ascertained 
 to avoid accidental rupture by attempting too much. 
 
 Propositions have been made to supersede cast-iron for rifles (and in 
 fact for smooth-bores also) by wrought-iron ; and a heavy wrought-irou 
 rifled gun of 7-inch bore, forged in a peculiar manner, is even now under 
 process of trial, as well as one of smooth-bore, designed and constructed 
 by our distinguished citizen, Mr. John Ericsson. But the experiments 
 have not been sufficiently advanced with either of these guns to form a 
 reliable judgment as to the probable result, for there are many grave 
 questions involved besides the ability to resist rupture, and these will 
 inevitably be developed under the strain of excessive charges. 
 
 For a long time the question of casting guns in a solid mass, and cool- 
 ing them from the exterior, or casting them hollow, and cooling from the 
 interior, upon the comprehensive plan of Major Eodman, has occupied 
 the attention of the bureau ; and in a paper presented to the department 
 on the subject, under date of May 17, 1864, an opinion was expressed 
 decidedly in favor of the latter for all the heavy guns of the navy. 
 
 As these views were subsequently fully sustained by the recorded 
 opinions of the best authorities of the army and navy, and of the founders 
 to whom the question was submitted, the official sanction of the depart- 
 ment is only needed to enable the bureau to adopt this plan of founding 
 in future all the cannon for the navy above an 8-inch calibre, after it shall 
 have been submitted to Admiral Dahlgren. It may be remarked, that 
 Mr. Parrott has recently determined to manufacture his heavy rifles in 
 this way, being convinced that he thereby obtains a more solid gun, of 
 greater uniform strength, and a surface of bore better suited to resist the 
 action of the rifled projectiles. 
 
 It would no doubt be interesting to describe fully the process of found- 
 ing cannon by both methods ; but the limits of a general official report 
 on various other subjects render this inexpedient. It is sufficient to know, 
 however, that they are each perfectly understood by the men engaged in 
 the business ; and since the casting of the enormous 20-inch cannon at 
 Fort Pitt foundry for the army and navy, there really would seem to be 
 
EXPERIMENTS ON HEAVY ORDNANCE. 157 
 
 no limit to the ambition and daring of OUT artisans. These huge masses 
 of iron were cast without the slightest difficulty, the time elapsing from 
 the moment of tapping the furnaces to the complete tilling of the monld 
 of the army gun being only 22 minutes. To produce this casting no less 
 than 105 tons of iron were melted. 
 
 This huge cannon having been bored and finished and the test speci- 
 mens confirming the opinion formed of the soundness of the metal in 
 working under the tools, it has been recently placed in battery at Fort 
 Hamilton, where it will be subjected to proof at an early day. 
 
 From the report of the Chief of Ordnance, War Department, for 1865. 
 
 The importance to the country of having the armaments placed in the 
 forts as rapidly as they can be prepared to receive them is so evident, 
 that I have caused the manufacture of sea-coast gun-carriages to be con- 
 tinued as rapidly as practicable at the two arsenals which possess the 
 proper facilities for making them ; and orders have been given to the 
 several founders, who have been engaged in making heavy guns for this 
 department, for as many guns as carriages can be made for. 
 
 I have been informed by the Chief Engineer that he will be prepared to 
 receive guns in the forts faster than carriages can now be made, and it 
 is in contemplation to increase the capacity for manufacturing sea-coast 
 carriages. 
 
 Experimental wrought-iron field and siege gun-carriages have also 
 been made and tested, with results so satisfactory as to render it certain 
 that these carriages may be advantageously substituted for the wooden 
 carriages, and it is proposed to make no more gun-carriages of wood. 
 
 The smooth-bore cannon of large calibre which have been used during 
 the war have given satisfaction, and are regarded as perfectly reliable. 
 The great importance of having reliable rifled guns of large calibre is 
 universally admitted, and the attention of this government, and of the 
 nations of Europe, has been directed to that object ; but so far, it is 
 believed, without entire success in its accomplishment. 
 
 The many failures, by bursting, of the celebrated Parrott guns in the 
 land and naval service have weakened confidence in them, and make it 
 the imperative duty of this department to seek elsewhere for a more reli- 
 able rifle gun. 
 
 Mr. Horatio Ames, of Falls Village, Connecticut, invented a plan of 
 making wrought-iron guns, which many believe would possess those 
 qualities which are so very desirable for guns of heavy calibre, and 
 although the cost of these guns was necessarily very great in comparison 
 with the cost of cast-iron guns, a conditional order was given to Mr. 
 Ames to manufacture 15 of them for the government, the condition 
 being that the guns should be superior to any rifled guns in the service. 
 One of these guns was fired under the direction of a board of officers, 
 who unanimously expressed the opinion that the "Ames wrought-iron 
 guns possess, to a degree never before equalled by any cannon of equal 
 weight offered to our service, the essential qualities of great lateral and 
 longitudinal strength, and great powers of endurance under heavy 
 charges ; that they are not liable to burst explosively and without warn- 
 ing, even when fired under very high charges ; and that they are well 
 adapted to the wants of the service generally, but especially whenever 
 long ranges and high velocities are required." The board also expressed 
 the opinion that the 15 Ames 7 -inch guns possessed sufficient weight 
 and strength to receive an 8-inch bore, and recommended that the gun 
 which had been fired under their direction should be reamed up to eight 
 inches and subjected to further trial. 
 
158 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 They further decidecUthat Mr. Ames had fulfilled the obligation incur- 
 red by him in his contract to furnish the gun, and that so many of the 
 guns as should endure a proof of 10 rounds with the service charge, and 
 pass the proper inspection, should be accepted and paid for. 
 
 Two of the 14 guns burst in proof, exhibiting serious defects in 
 their manufacture defects in welding which I had been apprehensive 
 could not be avoided. The guns which endured the proof of 10 rounds 
 were accepted and paid for by this department. 
 
 The gun which was fired under the direction of the board was bored 
 
 up to eight inches and fired 24 times with service charges, when it burst. 
 
 ###*##*# 
 
 Believing that, with our present knowledge of the properties pf metals 
 and our skill in working them, reliable rifle guns of large calibre can be 
 made of cast iron, I have, with your sanction, caused a pair of 8-inch rifle 
 guns of the supposed proper model and weight to be made. These guns 
 are now at Fort Monroe undergoing extreme proof, and should their 
 endurance be satisfactory it is proposed to have other guns like them 
 made. 
 
 From the report of tlie Chief of Ordnance, Navy Department, 1865. 
 
 THE FOUNDRIES. 
 
 The presumption is that the number of serviceable cannon which will 
 be found by survey, together with those now being received from the 
 contractors, will be amply sufficient to meet the wants of the navy for 
 several years, and therefore the bureau does not contemplate entering 
 into any new contracts for guns. The experience of the war has demon- 
 strated that we can rely upon the private enterprise of our citizens to 
 produce good cannon, and as rapidly as they are wanted. Therefore no 
 apprehension need be entertained of any difficulty arising from the 
 suspension of this work for the navy, and the return of these large work- 
 shops to producing machinery and tools for commerce and the arts ; on 
 the contrary, they will be better prepared with their acquired knowledge 
 to enter at once upon the work, and to manufacture either such guns as 
 are now in use, or upon any other models which future experiments may 
 prove to be better adapted for naval use. I of course have now especial 
 reference to cast-iron cannon, both smooth-bored and rifled, and to the 
 manufacture of bronze howitzers ; for the art of fabricating wrought-iroii 
 or steel cannon is yet in its infancy here, and remains an unsettled ques- 
 tion abroad, only to be solved by a well-conducted series of careful experi- 
 ments. So far, the results obtained by private enterprise in this country 
 are very doubtful, and by no means to be relied upon. In fact, the difficul- 
 ties of the problem are very much increased by the persistent efforts of 
 inventors to produce wrought-iron or steel rifled ordnance of large calibre, 
 instead of confining the preliminary trials to smooth-bore guns of the 
 ordinary size. 
 
 It should be remembered also that the advantages claimed for rifled 
 cannon over smooth-bores are in many respects visionary, and do not 
 bear the test of actual conflict, much less the more elaborate and quietly 
 pursued experiments of the practice ground j and that whatever of extra- 
 ordinary power or range may be obtained with them, is generally quali- 
 fied in a great degree by the danger of premature rupture, under the 
 strain of excessive charges and heavy projectiles necessary to produce 
 such effects, and this whether the rifles are made of cast iron, wrought 
 iron, or steel. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 159 
 
 During the recent rebellion the cast-iron smooth-bore guns of the navy 
 endured all of the severe service to which they were subjected, and proved 
 their excellence everywhere and under all the conditions of actual war. 
 Not a single gun of the Dahlgren system has burst "prematurely; and 
 none of the 15-inch guns, even when fired with their heaviest charges, 
 have ever failed except in the case of two or three which had their muzzles 
 ruptured by the premature explosions of shells, the body of the gun even 
 then remaining uninjured. For the ordinary warfare of wooden ships 
 against each other, or against forts, these smooth-bore guns are undoubt- 
 edly the best of their kind; while the practice at the test battery against 
 armor plating shows that even the 11 -inch at close quarters is capable 
 of piercing any thickness of iron or steel with which the sides of an ordi- 
 nary cruiser intended to keep the seas could be covered with safety, and 
 this without any danger of rupture from the use of increased charges, 
 unless the gun has been very much weakened by previous service. 
 
 The cast-iron rifled ordnance, manufactured by Mr. Parrott, of the 
 West Point foundry, for the navy, did also good service within their 
 sphere, and justly merited all the confidence placed in them, until it was 
 rudely shaken by the disastrous rupture of several 100 and 150-pounders 
 during the naval bombardment of Fort Fisher. 
 
 Prompt measures were immediately taken to ascertain, if possible, the 
 cause of these failures, and a board of ordnance officers, convened by 
 order of the bureau, investigated the subject in all its bearings. Their 
 final report is hereto appended. . 
 
 Without waiting, however, for the decision of this board, the bureau 
 directed the removal of the 150-pounders from service entirely, and re- 
 duced the charge of the 100-pounders to 8 pounds of powder and a shell 
 of 80 pounds. This reduction, and the gun confined to the work for 
 which it was intended, and not used for every occasion, especially where 
 the smooth-bores are more available, will,, it is believed, prevent the 
 occurrence of premature rupture in future, provided, however, that the 
 express and oft-repeated injunctions in relation to the use of rifled guns are 
 strictly observed. 
 
 The settled policy of the bureau is, at present, to arm our vessels with 
 a mixed battery of pivot and broadside smooth-bore guns, governed with 
 reference to calibre by the capacity and deck accommodation of individ- 
 ual ships. The rifled guns are exceptional, and are intended simply as 
 chase guns where long range is required, or to be used at great distances 
 in repelling the attack of smaller and swifter opponents armed with 
 similar pieces. 
 
 The idea of a broadside armament composed exclusively of rifled guns 
 is by no means warranted by the experience of the past war, and with 
 the gathered strength and prestige of our navy we can aiford to await 
 the results of the trials now going on in England and elsewhere, to bring 
 forward a rifled gun of large calibre which can be trusted and used as a 
 substitute for the smooth-bores in broadside or pivot.* Time, and a pro- 
 digious expenditure, with corresponding successful results, are needed 
 to satisfy ordnance men that the progress of science in the fabrication 
 of "built-up" guns, whether composed wholly of wrought-iron, or of steel 
 and wrought-iron combined, can produce either a rifled or smooth-bored 
 cannon which will take the place of our present comparatively inexpen- 
 sive cast-iron ordnance so far as endurance even is concerned. And 
 when this, the first essential, is determined conclusively, there remain 
 the other important questions between the smooth-bore and rifle of accu- 
 
 * Breech-loading cannon made of steel, by Krupp, are now being tried in Prussia and 
 Russia, but they find no favor in England. 
 
160 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 racy at all available ranges, penetration, shock, and the certainty of 
 ricochet fire. And in illustration of the advantage of this latter condi- 
 tion of licochet fire, as being peculiarly the property of smooth-bore, I 
 may refer to the published report of the army operations against Charles- 
 ton, in which the commanding general bears testimony to the magnificent 
 practice made by the iron-clad frigate New Ironsides with her 11-iuch 
 guns against Fort Wagner. He says, in speaking of the final operations 
 against that work: a Thirteen of our heavy Parrott rifles, 100, 200, and 
 300-pounders, pounded away at short though regular intervals at the 
 southwest angle of the boomb-proof, while, during the day-time, the New 
 Ironsides, with remarkable regularity and precision, kept an almost 
 incessant stream of 11-inch shells from her eight-gun broadside ricochet- 
 ing over the water against the sloping parapet of Wagner, whence, de- 
 flected upwards with a low remaining velocity, they dropped vertically, 
 exploding within or over the work, and rigorously searching every part 
 of it except the subterranean shelters." 
 
 A ricochet fire of this kind is simply impossible from rifled guns with 
 elongated projectiles, whatever may be said of their superior powers of 
 penetration. 
 
 But the first essential of endurance in these " built-up" guns is by no 
 means an accomplished fact, and in the development of any great power 
 which they ought to possess by using heavy charges, they have hitherto 
 developed also an inherent weakness which the greatest care in the pre- 
 paration and fabrication of the materials of which they are composed is 
 unable to overcome. A single gun may now and then be made which 
 will show remarkable endurance under protracted firing; but a second 
 or third, fabricated apparently like the first, yields prematurely, and dis- 
 appoints the inventor when he least expects it With cast-iron ordnance, 
 however, uniformity of endurance can be obtained even with rifles, as is 
 exemplified by the trials of the three 100 pounders by the board on rifled 
 ordnance, at Cold Spring, New York. 
 
 We may, therefore, content ourselves with the possession, at least, of 
 a system of smooth-bore and rifled ordnance which has stood the test of 
 no ordinary conflict; and that we have every reason to expect that ample 
 leisure will be afforded us in the future for the examination and trial of 
 any new theories which may be presented for investigation. 
 
 For this state of things we are mainly indebted to the enterprise of 
 our citizens who own and have so ably conducted the cannon foundries 
 of the north. 
 
 From tlie Report of the Chief of Ordnance, War Department, for 1866. 
 
 The experiments which have been carried on at Fort Monroe arsenal 
 to test the power and endurance of the 8-inch and 12-inch rifle guns, 
 made of cast iron, by this department, are highly satisfactory, and war- 
 rant the belief that cast-iron rifle guns, of these calibres, may be intro- 
 duced into the military service with safety and advantage. The 12-inch 
 rifle, throwing a projectile of 600 pounds, and with 55 pounds of powder, 
 has been fired 390 times. It is believed that no rifle gun of this calibre 
 has ever given so great endurance. The further trial of these guns will 
 be continued. 
 
 #*#**## 
 
 The armament of our fortifications now includes 3,546 serviceable 
 cannon, of which 1,334 are of heavy calibres, (20, 15, 10 and 8-inch bores) 
 and 653 are rifled cannon. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 161 
 
 From the Report of the Chief of Ordnance, Navy Department, for 1866. 
 
 The founding of cannon by either of the methods of solid or hollow 
 casting has been fully tried in this country, and the results have been 
 highly satisfactory. Nothing has yet transpired abroad in the efforts 
 which have been made to produce better guns than ours, of steel alone, 
 or built up of steel and wrought iron, to induce the fear that cast-iron 
 ordnance will be surpassed in any essential of endurance, either as 
 smooth-bores or rifles. As a notable instance in this connection, it may 
 be stated that an army cast-iron Eodman 12-inch rifle has been fired at 
 Fortress Monroe nearly 400 times, with charges of powder varying from 
 45 to 55 pounds, and shot weighing from 450 to 620 pounds. The gun 
 still endures this service without yielding. The bureau therefore hesi- 
 tates to recommend any expenditure in trials with built-up guns. 
 
 From the Report of the Chief of Ordnance, War Department, for 1867. 
 
 I stated in my last annual report that the work of arming the perma- 
 nent fortifications, and of increasing their efficiency by providing guns 
 of large calibre and replacing the perishable wooden carriages by dura- 
 ble wrought-iron carriages, had progressed rapidly, and would be con- 
 tinued as fast as the available means would admit until all the light 
 guns, which are ineffective against iron-clad vessels, and all wooden car- 
 riages, should have been superseded by the most durable and effective 
 articles of their respective kinds. 
 
 I am decidedly of opinion that this should be done, and that proper 
 armaments should be provided and placed in the permanent forts as fast 
 as they are prepared to receive them. 
 
 Heavy guns and gun-carriages cannot be provided and mounted in 
 the forts in a few days or in a few weeks, and if this government should 
 become suddenly involved in war with a maritime power, or if war 
 should be imminent, the country would not be satisfied if the important 
 forts were unprovided with their proper armaments, and would demand 
 the reason why they have not been provided, when Congress had furn- 
 ished the necessary means, and it would hold the War Department 
 responsible for the failure. 
 
 Entertaining these views, I have felt it to be my imperative duty to 
 provide guns and gun-carriages for the permanent forts as rapidly as the 
 engineer department was prepared to have them mounted, and as the 
 means provided by Congress would admit. 
 
 On the 30th of June, 1866, the armaments of the forts included 3,546 
 serviceable cannon, of which 1,334 were of heavy calibre, (20, 15, 10. and 
 8 inches,) and 6^3 rifled, a majority of the guns being of smaller calibre 
 than eight inches. 
 
 It is known that smooth-bore guns of less calibre than eight inches 
 are entirely ineffective against iron-clad war vessels, and should not 
 constitute a part of the armament of any of our important forts. 
 
 In December, 1866, this bureau was informed by the engineer depart- 
 ment that 2,152 guns of heavy calibre (20, 15, and 13-inch smooth-bores 
 and 10 and 12-inch rifles) would be required during the year 1867, or as 
 soon as they could be furnished. As some of the guns which were asked 
 for were of calibres and kinds which had not been adopted for our ser- 
 vice, I requested that a board of officers might be instituted to deter- 
 mine the calibres, the number of each calibre, and the proportion of 
 rifle guns to smooth-bores, required to arm the permanent forts. 
 
 The board, which was composed of engineer, ordnance, and artillery 
 Eep. No. 266 11 
 
162 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 officers, were unanimously of the opinion that u there would probably be 
 required for the permanent fortifications, in addition to the ordnance 
 now on hand, 805 smooth-bore guns of 20, 15, and 13 inches calibre, 810 
 rifles of 12 and 10 inches calibre, and 300 mortars of 15 and 13 inches 
 calibre, to be provided from time to time, as the readiness of the forts 
 to receive armament, the capacity of the foundries for its manufacture, 
 and the appropriations applicable to its procurement, may warrant." 
 
 This recommendation received the approval of the Secretary of War 
 ad interim. 
 
 None of these guns have yet been provided, and there are no existing 
 orders or contracts for heavy cannon. 
 
 Some of the forts are ready to receive guns of 13 inches calibre, and 
 none have yet been provided. It is worthy of consideration whether 
 some should not be provided at once and placed in the forts which are 
 ready to receive them. 
 
 This department recognizes the great importance of providing the very 
 best and most reliable heavy guns for arming the forts, and has used all 
 means within its control to obtain them. 
 
 The founders have not been allowed to use any but the best gun iron 
 known to the department, and it has been required that the metal in 
 every gun shall fulfil certain established conditions with respect to ten- 
 sile strength, density, and initial strain. A large number of guns have 
 been condemned before reception because the metal did not fulfil all of 
 the prescribed conditions. These requirements have produced excellent 
 results. 
 
 Persistent efforts have been made for some time past by ignorant or 
 designing persons to destroy public confidence in the heavy guns which 
 have been provided by the ordnance departments of the army and navy. 
 
 Iron castings, placarded as representing the condition of the metal in 
 our heavy guns, have been placed in conspicuous public places, and 
 publications have appeared from time to time in prominent journals 
 asserting that these guns were worthless; that they could only be fired 
 with very light charges of powder, and that they would burst if fired a 
 few times rapidly. 
 
 These attempts to injure the character of our heavy ordnance undoubt- 
 edly produced some effect on the public, and increased the responsibili- 
 ties of this bureau. 
 
 From the report of the Chief of Ordnance, Navy Department, for 1867. 
 
 Since the date of my last annual report, all existing contracts for 
 naval cannon have been completed and the guns delivered. With the 
 exception of the 15-inch guns, it is believed that the stock on hand will 
 meet the existing wants of the service. There is also a superabundant 
 supply of serviceable projectiles of all kinds, together with a sufficiency 
 of gunpowder, to meet the current demands of our cruisers. 
 
 Kecent trials in England of a 15-inch gun of navy pattern, cast on 
 Rodman's method, have fully vindicated the wisdom of the measure of 
 introducing this calibre of cast-iron ordnance into our service. 
 
 From the report of the Chief of Ordnance, War Department, for 1868. 
 
 In the last annual report from this office the unanimous opinion of the 
 board on the armament of fortifications, composed of engineer, ordnance, 
 and artillery officers, was quoted, showing the necessity of a large num- 
 ber of smooth-bore and rifle cannon for such armament. 
 
 In pursuance of this opinion, approved by the War Department, and 
 
EXPERIMENTS ON HEAVY ORDNANCE. 163 
 
 at the request of the Chief of Engineers, a few of these cannon have been 
 ordered, and are now nearly finished and ready for trial to test their 
 power and endurance. It will be necessary to have a considerable num- 
 ber of cannon manufactured of the kinds and calibre suitable for arming 
 permanent fortifications, and proportionate to the numbers they are now 
 in need of to make them effective against the most formidable attacks. 
 As the preparation and completion of such armaments require much 
 time, it is strongly recommended that the manufacture of the smooth- 
 bore cannon, whose power and endurance are well established, be car- 
 ried on, and that of the rifle cannon also, as soon as the results of the 
 practical tests will authorize it, as fast as the means applicable thereto 
 will admif. 
 
 My attention having been called by the Chief of Engineers to an error 
 in my annual report of last year, in which I say, " In December, 1866, 
 this bureau was informed by the engineer department that 2,152 guns of 
 heavy calibre (20, 15, and 13 -inch smooth-bores, and 10 and 12 -inch 
 rifles) would be required during the year 1867, or as soon as they can be 
 furnished." I take occasion to say that the letter of the Chief of Engi- 
 neers of December 13, 1866, which was before me when the paragraph in 
 my report was written, and from whictt the number was intended to be 
 taken, called for 2,202, and that a subsequent letter from the Chief of 
 Engineers, dated January 25, 1867, modified and reduced the number of 
 guns called for from 2,202 to 1,915, agreeing with the number recom- 
 mended by the armament board, as stated by me in my annual report 
 for 1867, and approved by the War Department. The letter of the Chief 
 of Engineers of January 25, 1867, was accidentally overlooked by me, 
 and hence the error in my report as to the number of guns required by 
 the engineer department, and which I beg leave to correct. 
 
 I believed that our heavy cast-iron guns were the cheapest and most 
 effective guns that were possessed by any nation, and experiments made 
 to test their power and endurance have shown that it is so. 
 
 The 20-inch gun has been fired with a charge of 200 pounds of powder 
 and a shot weighing 1,100 pounds, and I have no hesitation in saying 
 that this may be the regular charge for this gun. The range at 25 
 degrees elevation was more than 4 miles. 
 
 A 15-inch gun has been fired as follows, viz : 
 
 7 times with 40 pounds of powder and a shell weighing 350 pounds, 
 
 5 times with 50 pounds of powder and a shell weighing 350 pounds. 
 
 70 times with 50 pounds of powder and a shot weighing 434 pounds. 
 
 59 times with 55 pounds of powder and a shot weighing 435 pounds. 
 
 1 time with 60 pounds of powder and a shot weighing 434 pounds. 
 
 1 time with 75 pounds of powder and a shot weighing 434 pounds. 
 
 1 time with 80 pounds of powder and a shot weighing 434 pounds. 
 
 1 time with 90 pounds of powder and a shot weighing 434 pounds. 
 
 125 times with 100 pounds of powder and a shot weighing 434 pounds. 
 
 The mean range obtained with 100 pounds of powder and an elevation 
 of 32 degrees was 7,732 yards. 
 
 The mean initial velocity of the shot with the same charge was 1,510 
 feet per second. 
 
 The rounds were fired in 35 minutes, which was as rapidly as the gun 
 could be fired with 100 pounds of powder and a solid shot. 
 
 There is no enlargement of the bore from firing and the metal has not 
 been cut away by the powder. 
 
 The gun appears to be perfectly serviceable in every respect. 
 
 A 15-inch navy gun has been fired 12 times in 16 minutes with 40 and 
 55 pounds of powder and solid shot, without injury. 
 
164 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 A number of 15-inch navy guns were fired in action several hundred 
 times, and some of them with 60 pounds of powder and solid shot. The 
 muzzles of two of them were blown off in consequence of the premature 
 explosion of shells in the bores. No other injury was sustained by any 
 of the guns. 
 
 A 10-inch gun, the metal of which had a greater strain than the maxi- 
 mum limit which had been established, was fired as follows, and without 
 injury to the gun, viz : 
 
 18 times with 18 pounds of powder and a shot weighing 127 pounds. 
 
 17 times with 20 pounds of powder and a shot weighing 127 pounds. 
 
 2 times with 22 pounds of powder and a shot weighing 127 pounds. 
 
 453 times with 25 pounds of powder and a shot weighing 127 pounds. 
 
 120 times with 26 pounds of powder and a shot weighing 127 pounds. 
 4 times with 27 pounds of powder and a shot weighing 127 pounds. 
 1 time with 30 pounds of powder and a shot weighing 127 pounds. 
 
 Only one 12-inch rifle gun has been made for this department. It has 
 been fired as follows, and appears to be entirely serviceable, viz : 
 
 107 times with charges of powder varying between 35 and 85 pounds 
 and a shell weighing 477 pounds. t 
 
 341 times with charges of powder varying between 35 and 80 pounds 
 and a solid shot weighing 620 pounds. 
 
 With 50 pounds of powder the mean initial velocity of 75 shot was 
 1,139 feet per second. 
 
 These guns were cast hollow and cooled from the interior. 
 
 Their cost is less than one-seventh that of steel or wrought-iron guns 
 per pound, and they are believed to be more uniform in the quality of 
 the metal and more reliable than either steel or wrought-iron guns. 
 
 No other heavy guns have endured such proof or performed so much 
 work as these guns have done, and it is confidently claimed that they 
 are the cheapest, most reliable, and most effective heavy guns that have 
 yet been produced. It is known that several foreign powers have pur- 
 chased some of the 15-inch smooth-bores and 12-inch rifles in this country, 
 and that at least two nations of Europe are manufacturing 15-inch cast- 
 iron guns upon the plan which has been adopted by this department. 
 
 While the results of actual trial have satisfactorily demonstrated the 
 strength, efficiency, and reliability of our smooth-bore cast-iron cannon 
 of large calibres, and similar trials have warranted the same expectations 
 in regard to rifled cannon of cast iron, these latter have not as yet been 
 tested to a sufficient extent to authorize their adoption for the service in 
 preference to heavy rifled cannon of any other material. I should not, 
 therefore, feel justified in procuring any large number of these rifled 
 cannon at present, but would prefer to make further trials with such 
 number only of them as may be necessary for that purpose, and to await 
 the results before proceeding to procure the cannon of this kind which 
 our permanent fortifications will require. So important is it, in my 
 opinion, that these trials should be made, that I earnestly recommend 
 that two 10-inch and two 12-inch rifle guns be made at once and fired to 
 extremity, to test their power and endurance. 
 
 From the report of the Chief of Ordnance, Navy Department, for 1868. 
 
 Opinions differ quite as widely in regard to the preferable mode of 
 developing ordnance power; whether it shall be by smooth or rifled 
 bores by loading at breech or muzzle made from iron cast, or wrought, 
 or 'from steel solid or in connected parts; the relation of mass to velo- 
 city is also unsettled. In fact, the question involves the necessity of 
 
EXPERIMENTS ON HEAVY ORDNANCE. 165 
 
 going back to fundamental principles, and starting thence by well-con- 
 ducted experiments. 
 
 In England the government seems to have been satisfied, at first, to 
 abide by the views and the skill of the distinguished engineer Armstrong ; 
 but after a large experience and a heavy expenditure, another direction 
 has been taken. 
 
 In one of the recent French iron-clads, (the Belliqueuse,) I observed 
 very heavy rifled cannon were mounted loading at the breech a 
 system that has now lost favor with the English. 
 
 *" There is also a greater inclination to rifle cannon in England and 
 France than with us at the present time the experiences of battle 
 having largely corrected that tendency in our navy. 
 
 It is of national importance that these questions should be investigated 
 in the only way that their nature permits that is, by experiment. 
 
 We cannot take the conclusions of foreign powers, even if it were pos- 
 sible to know what they agree upon ; but we must search for ourselves 
 and be able, as well at) others, to carry the experience of the practice 
 ground into battle. 
 
 It is true that no pressing occasion seems to demand an immediate 
 exertion. We are at peace, and there is no sign of a war to which we 
 need be, or are likely to be, a party. But the great European family of 
 nations is alive with the apprehension of approaching war, and no one 
 can say at what instant its vast armies may be precipitated into deadly 
 conflict. When this comes it cannot be art internal struggle, but will 
 extend wherever the commerce or the distant possessions of civilization 
 are to be found. 
 
 Even so great a nation as the United States may be denied the priv- 
 ilege of neutrality. Orders in council and imperial decrees will again, as 
 of old, revive no peaceful discussion of the rights of belligerent and 
 neutral which are involved in the practice of search, of blockade, and 
 of contraband of war. How then shall our flag protect its neutral rights 
 against the strong hand of the aggressor in every sea, if not by its 
 ability to resist injustice when committed? 
 
 Even the ordinary intercourse of peace frequently requires the inter- 
 vention of our naval representative which, judiciously afforded, prevents 
 accidental misunderstanding from acquiring importance by delay. 
 
 The policy of the country always has been, and should be adhered to, 
 that however small our naval force in peace, every vessel of it shall com- 
 bine in itself the highest known qualities of a ship of war in armament, 
 speed, and personnel. Then, in case of an emergency, it will not be diffi- 
 cult to multiply these types to any extent. 
 
 As ordnance is the distinguishing feature in this question, I hope that 
 Congress will bestow the means which are now necessary to determine 
 what it shall be when iron-clads become the objects of fire. 
 
 From the report of Rear-Admiral Porter of the first attack on Fort Fisher. 
 
 One or two leading vessels having made the mistake of anchoring too 
 far off, caused those coming after them to commit a like error $ but when 
 they all got in to place and commenced work in earnest, the shower of shell 
 (115 per minute) was irresistible. So quickly were the enemy's guns 
 silenced that not an officer or man was injured. I regret, however, to 
 have to report some severe casualties by the bursting of 100-pounder 
 Parrott cannon. 
 
 One burst on board the Ticonderoga, killing six of the crew and 
 wounding seven others. Another burst on board the Yantic, killing one 
 officer and two men. Another on the Juniata, killing two officers, and 
 
166 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 wounding and killing ten others. Another on the Mackinaw, killing one 
 officer and wounding five others (men.) Another on the Quaker City, 
 wounding, I believe, two or three. Another ontheSusquehamia, killing 
 and wounding seven, I think. 
 
 The bursting of the guns (six in all) much disconcerted the crews of 
 the vessels when the accident happened, and gave one and all a great 
 distrust of theParrottlOO-pounders, and (as subsequent events proved) 
 they were unfit for serviceman d calculated to kill more of our men than 
 those of the enemy. 
 
 From the report of Rear-Admiral Porter of the second attack on Fort Fisher. 
 
 I believe we have burst all the rifled guns left in the fleet one on the 
 Susquehanna, one on the Pequot, and one on the Osceola and I think 
 the reputation of these guns is now about ruined. 
 
 WASHINGTON, D. C., February 6, 1867. 
 
 SIR: I have the honor to transmit herewith the "Proceedings of a 
 board of officers convened by virtue of Special Orders No. 29, War Depart- 
 ment, Adjutant Generals 7 office, Washington, January 18, 1867." 
 Yery respectfully, vour obedient servant, 
 
 T. G. BAYLOR, 
 Captain of Ordnance and Bvt. Col. U. 8. A., Recorder. 
 
 Brevet Major General L. THOMAS, 
 
 Adjutant General U. $. A., Washington, D. C. 
 
 Proceedings of a board of officers convened in virtue of Special Orders No. 
 29, War Department, Adjutant General's office, Washington, January 18, 
 1867. 
 
 Proceedings of a board of officers assembled at Washington, D. C., in 
 pursuance of the following order, viz : 
 
 [Special Orders No. 29 Extract.] 
 
 WAR DEPARTMENT, ADJUTANT GENERAL'S OFFICE, 
 
 Washington, January 18, 1867. 
 
 # * # * # # * 
 
 15. A board of officers is hereby instituted for the purpose of determining the calibres, the 
 number of each calibre, and the proportion of rifled guns which will probably be required 
 for the armament of fortifications. 
 
 Brevet Brigadier General William Maynadier, ordnance department; Brevet Major Gen- 
 eral W. F. Barry, colonel 2d U. S. artillery; Brevet Major General J. G. Barnard, corps 
 of engineers; Brevet Major General H. J. Hunt, lieutenant colonel 3d U. S. artillery; 
 Brevet Major General H. G. Wright, corps of engineers ; Brevet Colonel T. G. Baylor, 
 ordnance department. The board will meet at such time and place in this city as may be 
 designated by the senior member. The junior member will record the proceedings. 
 
 * * , * * * * * 
 
 By order of the Secretary of War : 
 
 E. D. TOWNSEND, 
 Assistant Adjutant General. 
 
 WASHINGTON, January 24, 1867. 
 
 The board met in pursuance of the above order, and on the call of the 
 senior member, at room No. 47 in the Ordnance Bureau, at 11 o'clock a. in. 
 
 Present: 1. Brevet Brigadier General Win. Mayuadier; 2. Brevet 
 Major General H. J. Hunt 5 3. Brevet Major General H. G. Wright. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 167 
 
 Absent: 1. Brevet Major General W.F.Barry; 2. Brevet Major Gene- 
 ralJ. G. Barnard; 3. Brevet Colonel T. G. Baylor. (Reasons not known.) 
 After some discussion in relation to the information which should be 
 procured for the use of the board from the Engineer and Ordnance 
 Bureaus, the board, in consequence of the absence of the three remaining 
 members, adjourned at 11.50 a. m., to meet at 11 a. m. to-morrow. 
 
 H. G. WEIGHT, 
 Brevet Major General, Recorder. 
 
 WASHINGTON, January 25, 1867. 
 
 The board met pursuant to adjournment. 
 
 Present: 1. Brevet Brigadier General Wm. Maynadier; 2. Brevet 
 Major General J. G. Barnard; 3. Brevet Major General H. J. Hunt; 4. 
 Brevet Major General H. G. Wright; 5. Brevet Colonel T. G. Baylor. 
 
 Absent: 1. Brevet Major General W. F. Barry. (Eeason not known.) 
 
 Brevet Major General J. G. Barnard and Brevet Colonel T. G. Baylor 
 reported themselves as having been detained by interruption of travel. 
 
 The proceedings of the previous day having been read, some discus- 
 sion was had with regard to the meaning of the order assembling the 
 board, as to whether other than rifled guns were to be considered. It 
 was, however, ascertained by reference to the letters of the Chief of 
 Engineers and Chief of Ordnance, which brought forth the order conven- 
 ing the board, that both smooth-bore and rifled guns were contemplated. 
 
 The communication marked A, accompanying these proceedings, was 
 read, having been referred to the board by the Chief of Ordnance. 
 
 The board then adjourned till Monday, January 28, at 11 a. m., to 
 await information from the engineer department with reference to the 
 present armament of fortifications, and also the arrival of Brevet Major 
 General W. F. Barry. 
 
 WASHINGTON, January 28, 1867. 
 
 The board met pursuant to adjournment, and the proceedings of the 
 previous day were read, all the members being present. 
 
 Brevet Major General W. F. Barry reported that he did not receive 
 the order convening the board in time to reach here sooner. 
 
 The board, after examining into and discussing the question of the 
 calibres of guns required for our permanent works, adjourned at 2 p. m. 
 until 12 in. to-morrow, to await further information from the engineer 
 department. 
 
 WASHINGTON, January 29, 1867. 
 
 The board met pursuant to adjournment. 
 
 Present all the members. The board, after some discussion, unani- 
 mously recommend that the calibres of the heavy ordnance hereafter to 
 be provided for the armament of permanent fortifications shall be: for 
 smooth-bore, 20-inch, 15-inch, and 13-inch guns, and 13-inch and 15-inch 
 sea-coast mortars; for rifled guns, 12-inch and 10-inch; and that guns of 
 other than the above calibres now on hand be used in the positions for 
 which they may be most suitable ; or in their present positions until they 
 can be replaced by guns of the calibres above specified. 
 
 Major General J. G. Barnard offered the folio wing 'resolution, which 
 was adopted by the board, viz : 
 
 Resolved, That, in the opinion of* the board, mortars may be made to 
 play an important part in the defence of channels, as well as in prevent- 
 ing anchorage ; and that, to ascertain what conditions are necessary to 
 
168 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 their efficiency, experimental firings should be made to determine what 
 force of iinpcct is necessary to break through the best protected decks 
 of iron-clad*. 
 
 The above resolution was amended by Brigadier General William May- 
 nadier, and the amendment adopted by the board, as follows : Resolved, 
 further, That, in the opinion of the board, it is of the highest importance 
 that experiments should be made to ascertain the absolute relative power 
 and efficiency of the 20-inch and 15-inch smooth-bore guns, and of the 
 12-inch and 10-inch rifled guns, against monitors and iron-clad vessels. 
 
 At 3.15 p. m. the board adjourned till 12 m. to-morrow, and directed 
 the recorder to procure a copy of the report of the board on armament 
 of fortifications, made February 14, 1862, and approved by the honor- 
 able Secretary of War March 27, 1862. 
 
 WASHINGTON, January 30, 1867. 
 
 The board met pursuant to adjournment ; all the members present. 
 The proceedings of the previous day were read. Major General Barnard 
 then offered the following resolution, which was adopted, viz: 
 
 Resolved, That it is not expedient for this board to recommend the 
 construction of any more 20-inch guns for service until their endurance 
 and capabilities have been experimentally demonstrated. On motion it 
 was resolved that in the opinion of the board, the Gatling gun, or a gun 
 of similar character, may be advantageously adopted in place of the 
 present flank defence howitzer. 
 
 The board resolved to take up the plans of the fortifications in New 
 York harbor for minute examination, in order to determine the general 
 principles which shall govern in fixing the proper positions for rifle 
 cannon, and thus enable them to arrive at the proper proportion of such 
 guns. 
 
 The board then adjourned till 12 m. to-morrow to wait for these plans. 
 
 WASHINGTON, January 31, 1867. 
 
 The board met pursuant to adjournment, and the proceedings of the 
 previous day read. On motion it was resolved that a committee of three, 
 to consist of one ordnance, one engineer, and one artillery officer, be 
 appointed by the senior officer of the board to examine into such details 
 of the plans of fortifications, and of the character of the approaches 
 thereto, as may indicate the proper kind of guns, whether rifled or smooth- 
 bore, to be placed in position, and to report the result of their examina- 
 tion to the board as soon as practicable. The following named officers 
 were appointed the committee by the senior officer of the board, viz : 
 
 1. Brevet Major General H. J. Hunt. 
 
 2. Brevet Major General H. G. Wright. 
 
 3. Brevet Colonel T. G. Baylor. 
 
 The board then adjourned, at 1 o'clock p. m., until the committee were 
 ready to report. 
 
 WASHINGTON, January 31, 1867. 
 
 The committee met in room No. 9 of the Engineer Bureau, at 1.30 p. 
 m., and proceeded to examine the maps and plans of the forts designed 
 for the defence of New York harbor. The armament for which pro- 
 visions are already made or will soon be finished, for the forts at Sandy 
 Hook and the battery near Fort Hamilton, was then fixed as follows: 
 
 Sandy Hook. Sixty-nine 10-inch rifles, thirty- six 13-inch smooth-bore 
 guns. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 169 
 
 Battery near Fort Hamilton. Fifteen 12-inch rifles, two 10-inch rifles, 
 fourteen 15-inch smooth-bore guns. 
 
 The committee, at 4.15 p. m., adjourned to meet at the same place at 
 11 a. m. to-morrow. 
 
 WASHINGTON, February 1, 1867. 
 
 The committee met pursuant to adjournment, all the members present, 
 and resumed the consideration of the armament of the forts for the 
 defence of New York harbor. The following armament was agreed 
 upon : 
 
 Fort Wadsworth. Seventy-eight 10 -inch rifles, forty- three 13-inch 
 smooth-bore guns, one 10-inch smooth-bore gun. 
 
 South Cliff battery. Eleven 12-inch rifles, eight 15-inch smooth-bore 
 guns. 
 
 Battery Hudson. Ten 12-inch rifles, twelve 15-inch smooth-bore guns, 
 two 10-inch smooth-bore guns. 
 
 North Cliff battery. Twenty 15-inch smooth-bore guns. 
 
 Castle Williams. Five 15-inch smooth-bore guns. 
 
 Fort Columbus. Six 12-inch rifles, four 10-inch rifles, seven 15-inch 
 smooth-bore guns, four 13-inch smooth-bore guns. 
 
 South battery. Four 10-inch rifles, three 13-inch smooth-bore guns. 
 
 Fort Wood. Seventeen 10-inch rifles, eleven 15-inch smooth-bore guns. 
 
 Fort Gibson. Four 12-inch rifles. 
 
 Fort Schuyler. Eight 12-inch rifles, fifty -three 10-inch rifles, four 15-, 
 inch smooth-bore guns, seven 13-inch smooth-bore guns. 
 
 The committee, at 2.30 p. m., adjourned till 11 a. m. to-morrow. 
 
 WASHINGTON, February 2, 1857. 
 
 The committee met pursuant to adjournment, all the members present, 
 and after the proceeedings of the previous day were read, fixed upon 
 the armament of the fort at Willet's Point as follows : 
 
 Fort at Willet's Point. Eighteen 12-inch rifles, nineteen 15-inch smooth- 
 bore guns. 
 
 This completed the examination of the forts for the defence of New 
 York harbor. 
 
 The committee find, upon examination, that the x>roportion of rifled to 
 smooth-bore guns thus determined upon is 15 to 13 ; but they would 
 deem an equal division to be about the best distribution that could be 
 made from their present knowledge of the capabilities of the two kinds of 
 guns. 
 
 The committee having finished the business before it, notified the 
 senior member of the board that they would be, ready to submit their 
 report to the board in full, session on Monday next, February 4, 1867. 
 The committee then adjourned at 12.15 p. m. 
 
 WASHINGTON, February 5, 1867. 
 
 The board met at the call of the senior member at room No. 47 in the 
 Ordnance Bureau at 12 m., all the members present. The proceedings 
 and report of the committee having been read, the senior member pro- 
 posed the question, shall the report of the committee be adopted"? The 
 vote being taken, the report was adopted unanimously. 
 
 The following remarks were then presented to the board by Brevet 
 Major General J. G. Barnard: 
 
 The board have investigated attentively the subject submitted to 
 them and would respectfully state that the problem at the present 
 
170 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 moment, " What shall be the probable absolute number of different cali- 
 bres, and what shall be the proportion of rifled guns required for our 
 fortifications," is peculiarly indeterminate. This will be apparent from 
 the following considerations: 
 
 Whenever armament boards have been heretofore convened, their 
 duties have been, taking as fixed the number and emplacement of guns 
 in the forts and batteries as prepared by the engineer department, to 
 determine simply what guns shall be placed in them. In the case of the 
 present board, however, it has first to deal with an entire new class of 
 guns, of far greater power than those existing when the number of exist- 
 ing "emplacements" was fixed by the engineer department. Second, 
 with casemates and platforms not intended for such guns and generally 
 illy applicable or inapplicable to them. Third, the modifications required 
 in the works themselves, to enable them to receive our new guns and to 
 resist modern artillery, are not yet determined upon by the engineer 
 department, though in course of experimental investigation. A board 
 of engineers, convened by the honorable Secretary of War in 1864, (and 
 whose proceedings were approved by him,) to investigate the modifications 
 required in our permanent works, recommended very important changes 
 in the disposition of guns in our barbette batteries, suppressing plat- 
 forms, introducing traverses, &c. ; while they at the same time emitted 
 the opinion that the substitution of such guns as the 15 inch smooth- 
 bore and corresponding rifle would justify a reduction in the total num- 
 ber required. At the same time we believe that the relative capabilities 
 of the smooth bore and heavy rifle (of heavy ordnance) have not been 
 sufficiently investigated, experimentally, to enable an intelligent decision 
 to be made as to the best proportion to be adopted. These remarks will, 
 we think, show conclusively that any determination of the "number of 
 each calibre an/1 proportion of rifled guns that will probably be required 
 for our fortifications" would be at the present moment very illusory. 
 The board have therefore contented thenisejves with reviewing the dif- 
 ferent ports and harbors to be defended, and giving such a judgment as 
 they best may, attaching no value to it as an ultimate determination, 
 but merely as one which will enable the ordnance department to con- 
 tinue in the best probable way its construction of guns. 
 
 The vote having been taken as to the adoption of the foregoing 
 remarks, resulted as follows: 
 
 Ayes Brevet Major General W. F. Barry, Brevet Major General J. 
 G. Barnard, Brevet Major General H. J. Hunt, Brevet Major General 
 H. G. Wright, Brevet Colonel T. G. Baylor 5. 
 
 Noes Brevet Brigadier General William Maynadier 1. 
 
 The board is unanimously of opinion that for the permanent fortifica- 
 tions there will probably be required, in addition to tiie ordnance now on 
 hand: 
 
 15 20-inch guns, 190 15-inch gnus, 600 13-inch guns, smooth bores'; 200 
 12-inch guns, 610 10-inch guns, rifles ; 50 15-inch mortars, and 250 13-inch 
 mortars; to be provided from time to time as the readiness of the forts to 
 receive armament, the capacity of the foundries for its manufacture, and 
 the appropriations applicable to its procurement may warrant. The 
 board, at 1.45 p. m., adjourned till 12 m. to-morrow, to allow the recorder 
 time to write up the proceedings. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 171 
 
 WASHINGTON, February 6, 1867. 
 
 The board met pursuant to adjournment; all the members present. 
 The proceedings having been read to the board, they were signed. 
 The board, at 12.30 p. m., adjourned sine die. 
 
 WM. MAYNADIEE, 
 Brevet Brigadier General U. 8. Army. 
 
 WILLIAM F. BAEEY, 
 Colonel 2d Artillery, Brevet Major General. 
 
 J. G. BAENAED, 
 Colonel of Engineers, Brevet Major General. 
 
 HENEY J. HUNT, 
 Brevet Major General. Lieutenant Colonel 2d Artillery. 
 
 H. G. WEIGHT, 
 Lieutenant Colonel of Engineers and Brevet Major General. 
 
 T. G. BAYLOE, 
 Captain of Ordnance and Brevet Colonel U. 8. A. 
 
 A. 
 
 BALTIMORE, MARYLAND, 
 
 January 18, 1867. 
 
 Whereas the duties prescribed to this board involve experimental 
 tiring to determine how our existing works are to be modified, and 
 whereas such modifications depend upon the character of the guns to be 
 used ; and whereas a considerable number of our best sea-coast fortifica- 
 tions are already constructed, having casemates in which it is impossible 
 by any modification to introduce a 15-inch gun without diminishing 
 much its traverse and leaving sections without casemate fire; and 
 whereas, the English experiments show that the Palliser chilled iron 
 shot is the most formidable projectile against iron defences, and that our 
 own iron defences will be attacked by such or by steel projectiles : 
 
 Resolved, That it be represented to the ordnance department that it is 
 very desirable to have for such works, and perhaps for some others, a 
 gun of nine or ten inches calibre, which, like the Woolwich 9-inch gun, 
 will burn 40 or more pounds of powder, and throw at least a 250-pound 
 projectile. Further, 
 
 Resolved, That it be suggested to the ordnance department that pro- 
 jectiles of this character be furnished for the 12 and 15-inch guns at 
 
 Fort Monroe for our experimental firing. 
 
 '"* * * * 
 
 C. B. EEESE, 
 Bvt. Brig. Gen., Captain of Engineers, Recorder. 
 
 ENGINEER DEPARTMENT, 
 
 January 22, 1867. 
 
 Copy respectfully furnished to the Chief of Ordnance and recommended 
 for favorable consideration. 
 
 A. A. HUMPHEEYS, 
 
 Chief of Engineers. 
 
172 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 ORDNANCE OFFICE, 
 
 January 25, 1867. 
 
 Respectfully referred to the board on the armament of fortifications. 
 
 A. B. DYER, 
 
 Brevet Major General, Chief of Ordnance. 
 A true copy : 
 
 T. G. BAYLOR, 
 Captain of Ordnance and Brevet Colonel U. S*A. 
 
 [Endorsements. ] 
 
 WASHINGTON, D. 0., February 6, 1867. 
 
 T. G. Baylor, captain of ordnance, recorder, transmits proceedings of 
 a board of officers, of which Brevet Brigadier General William Maynadier 
 was president, convened to determine the number and calibre of guns 
 which will be required for the armament of fortifications. 
 Respectfully submitted to General Grant. 
 
 E. D. TOWNSEND, 
 
 Assistant Adjutant General. 
 ADJUTANT GENERAL'S OFFICE, 
 
 February 7, 1867. 
 
 HEADQUARTERS ARMY, 
 
 February 20, 1867. 
 
 Respectfully forwarded. Approved. 
 
 U. S. GRANT, General. 
 
 AUGUST 28, 1867. 
 Approved by the Acting Secretary of War. 
 
 ED. SCHRIYER, 
 
 Inspector General. 
 
 ADJUTANT GENERAL'S OFFICE, 
 
 Washington, September 4, 1867. 
 
 Respectfully referred to Brevet Major General A. B. Dyer, Chief of 
 Ordnance, with reference to the approval of the Secretary of War en- 
 dorsed hereon. 
 
 E. D. TOWNSEND, 
 
 Assistant Adjutant General. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 
 
 173 
 
 SCO 1C CO 00 ~^ 00 SO 1 
 ?. 55 1> O 50 8> 35 i 
 
 ^3* t* Ci OS ti O5 O <^ 
 
 38 
 
 n f- 
 
 
 o I > 
 
 spnnoj 
 
 ill 
 
 11 
 
 II 
 
 1! 
 
 S^ooooooo 
 ig <5 n3 n? *5 <5 *S*tr 
 
 P40 
 
 1 IO O 1C J 
 
 > CO O CC ' 
 ) 00 00 GO r 
 
 t^n n oo" c? t^"-*" r 
 
 ||||g 
 
 lO'0'fff )." 
 
 
 21 
 
 
 
 ,0000000000000000000000000 
 
 : :i i i ; i : -as i i ; i i i ; is i 
 
 i :S i i 
 
 I ill 
 
 Mo 
 
 
 la*."- 
 
 il^'ll 
 
 l 
 
 ooc] 
 .2"H.a 0.0. 
 
 65355 
 
 -aod 
 
174 
 
 EXPERIMENTS ON HEAVY ORDNANCE. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 175 
 
 % 
 
 APPENDIX D. 
 
 TECHNICAL AND MISCELLANEOUS EXTRACTS. INITIAL TENSIONS. 
 
 Extracts from u experiments on metals for cannon and cannon poivderj 7 
 * Rodman, page 96. 
 
 The solid gun, cooling from the exterior in an open pit, and being of 
 iron that contracted very much in cooling, was doubtless thrown upon a 
 very heavy strain, the exterior being compressed and the interior elon- 
 gated $ while the hollow gun, being rapidly cooled from the interior and 
 prevented from cooling from the exterior, was thrown upon a strain just 
 the reverse of the solid one. And I have no doubt that the interior of 
 the solid gun was broken before the exterior was relieved from the pres- 
 sure to which it had been subjected in cooling; while in the hollow gun 
 the great object of my improvement was in part, if not fully, attained, 
 viz., to throw the gun upon a strain, such, that under the action of the 
 law of strain, as stated above, each one of the infinitely thin cylinders 
 composing the thickness of the gun shall be brought to the breaking- 
 strain at the same instant. This condition would give us for the effective 
 resistance to rupture in a gun one .(1) calibre thick, 2#, instead of fa 
 which has been shown to be all that could be obtained from a gun free 
 from strain by cooling and is, doubtless, much more than can possibly 
 be attained in practice. The higher the metal, and the greater its con- 
 traction in cooling, and the more rapidly the gun is cooled, the further 
 will the solid one fall below a, and the more nearly will the hollow one 
 approach 2a, provided the cooling be effected from the interior ; also, the 
 greater the diameter of the solid gun, the greater will be the strain from 
 cooling. It is not considered practicable to cool a gun so rapidly from 
 the interior as to cause rupture to commence on the exterior. 
 
 Extract from the report of the Joint Committee on the Conduct of the War. 
 
 The Dahlgren gun is the invention of Eear- Admiral John A. Dahlgren, 
 and is distinguished by its exterior form. The plan adopted to avoid the 
 strain consequent upon cooling a solid casting of large size from the out- 
 side is to make the casting considerably larger than would otherwise be 
 needed to produce a gun of the required size, anneal it after cooling, and 
 then turn it down to the proper size and form. But the Dahlgren guns 
 of the largest calibre are now being manufactured upon the Eodman 
 principle. 
 
 The Rodman gun, while having to some extent its peculiarity of form, 
 is principally distinguished by the mode adopted in its manufacture, 
 which is an invention of Major T. J. Eodman. The casting is made 
 around a hollow core, or core-barrel, as it is termed, into which is intro- 
 duced a stream of cold water, the outside of the casting being kept heated 
 until the cooling from the interior reaches the outer portion of the mass 
 of metal forming the casting. This mode of manufacture, it is claimed,, 
 insures two important advantages over the old method of casting the 
 gun solid and then boring it out. The strain upon the metal produced 
 by cooling in large masses is reversed, rendering the gun less liable to 
 burst from the explosion of the powder in it ; and a much greater degree 
 of hardness is given to the interior surface, rendering the gun less liable 
 to abrasion in the bore by the passage of the projectile along it and the 
 action of the gases ^of the powder upon the metal. It is generally held 
 by the witnesses ,that no effective gun of large calibre can be made of 
 cast iron except upon the Eodman principle, or the principle of cooling 
 from the interior. 
 
176 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 Extracts from Mallet on Artillery. 
 
 SEC. 32. A certain amount of contraction on becoming solid from the 
 liquid state occurs in all castings. It is well known to practical found- 
 ers that for cast iron this is variable, and depends upon the mass of the 
 casting, being greatest for small and least for large castings of the same 
 "make" of iron; but it is obvious, and it follows from Mr. Bolley's 
 researches, that the contraction also will be greater in proportion as the 
 metal' is poured into the mould at a higher temperature, although, from 
 the expansion in the act of crystallizing, the specific gravity of the solid 
 mass maybe less at the higher than at the lower temperature of" pouring. 7 " 
 
 SEC. 33. As, therefore, there are two conditions that principally affect 
 the degree of contraction the total change of volume between the liquid 
 metal and its solid casting, namely, the extent to which the fluid metal 
 as entering the mould has been expanded by elevation of temperature 
 and the state of final aggregation of the crystalline particles, which we 
 have seen depends much upon the former so there will be a determinate 
 amount of contraction due to a determinate thickness or mass of casting, 
 irrespective of, though "also related to, the co-efficient of contraction for 
 any particular "make" of iron; for there is no doubt that different 
 makes, cceteris paribusj contract somewhat differently. From whenc.e it 
 follows that different parts of the same casting, if differing materially 
 in scantling or mass, will have different amounts of final contraction. 
 
 SEC. 34. Sudden changes of form or of dimensions in the parts of 
 cast-iron guns, besides the injury they do to the crystalline structure of 
 the mass, introduce violent strains, due to the unequal contraction of 
 the adjoining parts, whose final contraction has been different. 
 
 How desirable is it, therefore^ to introduce such alterations of the 
 forms of our ordnance as shall avoid those sudden and enormous (and 
 often useless) changes of adjacent mass, that we observe; as for example, 
 in the sea and land service 13-inch mortars, where at the chamber (where 
 the strain being as D is least) the thickness of metal suddenly approaches 
 twice that of the chase a malconstruction the full evils of which we 
 have yet to consider. 
 
 SEC. 35. The amount of lineal contraction due to solidification of cast- 
 iron, appears to vary with metal and circumstances of casting, from T i s 
 up to gL of the dimensions of the cold mass. Its contraction in volume, 
 therefore, (more than three times this,) and probably not equal in the 
 directions of three rectangular axes, owing to the christalline struc- 
 ture, is so great, and the difference such, between its measure for large 
 and small parts of the same casting, that the latter never should be 
 neglected. 
 
 SEC. 43. Besides the effects already referred to, due to the contrac- 
 tion of cast-iron in becoming solid, another class of abnormal strains 
 introduced by the consolidation of one portion of a casting before another 
 must not be passed over, as often producing results of the most import- 
 ant character in artillery. This will be more readily understood by 
 immediate reference to example. When a large gun, or, still more, a 
 large mortar, is cast solid, and the metal cools in the ordinary way, the 
 external portions solidify long before the interior has ceased to be liquid, 
 and the process of solidification is propagated, as it were, in parallel 
 "couches" from the outside to the centre of the mass. The lineal con- 
 traction of any one couch assumed of indefinite thickness is in the 
 direction of its circumference directly proportionate to that circumfer- 
 
EXPERIMENTS ON HEAVY ORDNANCE. 177 
 
 ence; and so it would seem (at first) that the contraction of the whole 
 assemblage should be at every point proportionate to its distance from 
 the centre, and that so the solid when all cold, should be left in a state 
 of molecular equilibrium. This is not the case, however, for no sooner 
 has the first couch or thickness of solid crust formed on the exterior, 
 than it forms a complete arch all around, so that the contraction between 
 fluidity and solidification of each subsequent couch is accommodated 
 (the continuity of the mass remaining unbroken throughout) by portions 
 of matter withdrawn radially from the interior toward the still cooling 
 exterior; that is to say, from a smaller towards a larger circumference. 
 SEC. 53. Unequal cooling, especially if very rapid, involves all the 
 injury that violent internal wrenching and straining can do to strength, 
 strains of the very same character as those under which it is part of the 
 purpose of this paper to show, that guns burst, and which often, in 
 the every day practice of the iron-founder, result in actual fracture. 
 
 Extract from the testimony of Brigadier General George D.Ramsey Before 
 the Joint Committee on the Conduct of tlie War. 
 
 Q. In what does the patent consist in this Eodman gun for which this 
 royalty is paid by the government to Mr. Knap ; and in what does the 
 difference consist between that gun and guns cast in the common or 
 ordinary mode ? 
 
 A. Heretofore all cannon were cast solid and allowed to cool in the 
 casting pit. In this way the cooling of the fluid metal from the exterior 
 extended gradually towards the inside, which was the last part that 
 solidified. The shrinkage by this mode of cooling tended to separate 
 the interior layers of metal from the exterior. In Hodman's plan, the 
 patent consists of cooling from the interior and keeping the outside hot; 
 the shrinkage begins on the inside of the mass, and each layer of metal 
 as it cools shrinks upon the nearest interior layer, thus binding all the 
 successive layers together. 
 
 Extract from Ordnance and Armor, " Holly? p. 234. 
 
 278. I. Increasing the thickness of the walls. The most obvious means, 
 of enabling any vessel to sustain a greater elastic pressure, such as the 
 gas of exploded gunpowder, is to simply thicken its sides, thus increasing 
 the area of substance to be torn asunder. This rule is founded upon the 
 practical facts of every-day engineering, which usually deal with com- 
 paratively low pressures and thin walls. Even in case of guns of small 
 calibre it has proved tolerably safe. But when these conditions are 
 greatly changed when the problem is, for instance, to throw projectiles 
 of 13 to 15 inches diameter at the rate of 1,500 to 1,800 feet per second, 
 and the gun is proportionally thickened to stand the excessive strain due 
 to both the increased pressure per square inch and the increased num- 
 ber of square inches pressed upon, another law, unobserved in ordinary 
 practice, assumes a very serious importance. This law is thus clearly 
 explained by Captain Blakely : * 
 
 279. To obtain much greater strength by casting guns heavier is 
 impossible, because in cast guns (whether of iron, brass, or other 
 metal,) the outside helps but very little in restraining the explosive 
 force of the powder tending to burst the gun, the strain not being com- 
 municated to it by the that intervening metal. The consequence is in 
 large guns the inside is split, while the outside is scarcely strained. 
 This split rapidly increases, and the gun ultimately bursts. 
 
 This will be more easily understood by considering the case of a 
 much more elastic tube; for instance, an India-rubber cylinder, 10 
 inches in internal diameter and 10 inches thick, therefore 30 inches 
 in external diameter. Such a cylinder might be strained by pressure 
 
 * A Cheap and Simple Method of Manufacturing Cannon,. 1858. 
 
 Eep. No. 266 12 
 
178 
 
 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 Fig. 131. 
 
 Fig. 132. 
 
 from within till the inside stretched to double its original circumference. The diameter 
 would, of course, also be doubled, and would be 20 inches instead of 10. 
 
 Now it is evident that the outside circumference and diameter cannot be doubled at the 
 Fig. 130. same time, or else the latter must become twice 30 or 60 inches 
 
 which would give a thickness of 20 inches, quadrupling the mass 
 of material, which is impossible. A moment's reflection shows 
 that the thickness must diminish as the circumference is increased 
 by pressure from within, for if the thickness remain 10 inches 
 when the internal diameter has become 20, the external diameter 
 must be 20 plus twice 10, or 40 inches. This could not be unless 
 we imagine w r hat seems impossible, viz, that the bulks of the 
 material is considerably enlarged, as each inch in length of the 
 cylinder would now contain 1,200 cylindrical inches, (the differ- 
 ence between the squares of 40 and 20, the external and internal 
 diameters,) whereas, originally, it only contained 800 inches, the 
 difference between the squares of 30 and 10. 
 
 Yet, even if the thickness could remain the same, notwithstand- 
 ing the increase of circumference, the outside layer could only be 
 strained one-third as much as the inside one, because three times as 
 long. The same elongation, which w r ould cause a strain of one 
 ounce or one pound in the longer circumference, would cause a 
 strain of three ounces or three pounds in the shorter one, and the 
 elongation which would but moderately strain the one would break 
 the other. This reasoning is equally applicable to the minute 
 extension of iron ; the increase of one-tenth of an inch in the outer 
 circumference of a 10-inch gun being possible without fracturing 
 that part, being an elongation of but one in 940 ; whereas the same 
 extension must crack the inside, as no iron could stand an elon- 
 gation of one-tenth in 31^, or one in 314. 
 
 Even on this showing, then, the outside of a thick tube cannot 
 do its share of work ; a closer examination, however, must con- 
 vince us that this is an over-estimate of it, for the thickness of mate- 
 rial must diminish as the circumference is increased. When the inner 
 diameter of the 10-inch cylinder becomes 20 inches, the thickness must 
 diminish from 10 to 7.32 inches, the cross-section of the cylinder 
 remaining the same. This cross-section was originally 800 circular 
 inches, 800 being the difference between the squares of 30 inches, 
 the inner, or 900 minus 100. When stretched the area of the cross- 
 section must continue to be 800 round inches. Now a thickness of 
 7.32 inches gives us an external diameter of twice 7.32 or 14.64 
 added to 20, the internal diameter, in all 34.64 inches, the square 
 of which is 1,200. Subtracting 400, the square of 20 leaves 800 
 round inches as before. In this case the outside of the cylinder is 
 stretched but 4.64 in 30, about one in seven, when the inside is 
 stretched to double its original size. If the inner diameter be only 
 stretched to 11 inches the thickness must be diminished from 10 
 to 9.674 inches, the outer diameter becoming 30.348 inches, the 
 cross-section remaining 800 round inches, as before, the difference 
 between the squares 30.348 and 11. Here the outer layer is elon- 
 gated .348 in 30, or 1 in 86; whereas the inner is extended 1 in 10, 
 showing a strain or an exertion of power 8 times greater. 
 
 In the minute extension of metals the disproportion is still more 
 striking. Thus in cast-iron the 10-inch inner diameter may become 
 1 OTCRJ? which wou ld extend the outer diameter only from 30 to 30^^, 
 the cross-section remaining 800 inches, and the thickness dimin- 
 ishing from 10 inches to 9|t)o. Here the outside would only be 
 stretched ^^ in 30, or 1 in 9,000, the inside being stretched yjj^ 
 in 10, or 1 in 1,000, exerting, therefore, nine times as much power 
 a? the outside. It is evident that a slight increase of pressure 
 from within would break the inside, while the outside could help but 
 little in restraining the disruptive force. 
 
 280. If we make equidistant circular marks on the end of an 
 India-rubber cylinder, (Fig. 134,) and stretch it, we can see 
 plainly how much more the inside is strained than the outside 
 India-rubber cylinder, with or cven the intermediate parts. The spaces between the marks 
 equidistant concentric marks, will become thinner, each space becoming less thin than that inside 
 
 Fig. 133. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 
 
 179 
 
 The same cylinder stretched by 
 
 Fig. 136. 
 
 Cylinder burst by internal pres- 
 
 of it, but the inner space much thinner than the other?, (see Fig. 135. 
 
 Fig 135,) showing that when the inside is strained almost to 
 breaking, the intermediate parts are doing much less work, 
 and those far removed almost none. 
 
 281. Law of strength of cylinders. In the first volume of the 
 "Transactions" of the Institute of Civil Engineers, p. 133, 
 there is a naper by Professor Peter Barlow, F. R. S., on the 
 Strength of Cylinders. The law he deduces is, that "in 
 cylinders of metal the power exerted by different parts varies 
 inversely as the squares of the distances of the parts from the axis." 
 Thus, in a 10-inch gun, when the inside, which is five inches 
 from the axis, is fully strained, the metal two inches from the 
 inside, or seven inches from the axis, can only exert a force f f , 
 or little more than half as much ; three inches further, ten inches^ 
 from the axis, the force exerted diminishes to &, or but a 
 Barter of that exerted by the inside ; and if the gu be twelve 
 
 inches thick, the outside, which is seventeen inches from the of the exterior. 
 
 axis, can exert but ^ 9 , or about ^ as much power as the 
 
 inside. Of course, casting the gun still thicker would add but 
 
 very little to its strength ; we cannot, therefore, be astonished 
 
 that it has been found in practice that cylinders for hydraulic 
 
 presses, with a thickness equal to about one-half the diameter 
 
 of the piston, are very nearly as strong as if ten times as thick. 
 
 282. In 1855, Dr. Hart, of Trinity College, Dublin, investi- 
 gated the problem. His calculations (see note W, p. 259, of 
 Mr. R. Mallet's work on the Construction of Artillery) give 
 greater strength to the inner parts, but still less to the outer, than 
 those of Professor Barlow. Both these gentlemen, as well as 
 General Morin, and Dr. Robinson, the astronomer, who have 
 also studied the question, agree that no possible thickness can 
 enable a cylinder to bear a pressure from within greater on each 
 square inch than the tensile strength of a square inch bar of the 
 materiul; that is to say, if the tensile strength of cast-iron be sure. 
 six tons per inch, a cylinder of that metal, however thick, cannot 
 bear a pressure from within of six tons per inch. 
 
 283. The report of experiments made by the United States govern- 
 ment in bursting hollow cylinders by internal pressure states that "the 
 general range of the results appears to sustain Mr. Barlow's hypothesis. 7 '* 
 
 284. In further proof of the foregoing facts. Captain Blakely cites the 
 actual fracture of some cylinders (Fig. 136) made by Mr. Longridge, of 
 iron wound with wire. The cracks were u much more open at the inside, 
 and some not extending to the outside." 
 
 285. The law of diminution in the power of resistance is also illustrated 
 by Professor Treadwell, who states it as follows :t 
 
 Suppose such a cylinder to be made up of a great number of thin rings or hoops, placed 
 one within another. Then the resistance of these rings, compared one with another, to any 
 distending force, will be inversely as the squares of their diameters. If we make a cylin- 
 der of 4 1 concentric hoops of equal thickness, disposed one within another, and exactly fitting, 
 so that the particles of each hoop shall be in equilibrium with each other, the diameter of the 
 largest being five times that of the smallest, then the force of each, beginning with the inner- 
 most, to resist distension, will be represented by the following numbers : 
 
 1000 ........ 444 ........ 250 ........ 160 ......... Ill ......... 82 ......... 62 ......... 49 
 
 826 ........ 391 ........ 225 ........ 148 ......... 104 ......... 77 ......... 59 ......... 47 
 
 694 ........ 346 ........ 207 ........ 137 ......... 98 ......... 73 ......... 56 ......... 45 
 
 591 ........ 309 ........ 189 ........ 128 ......... 92 ......... 69 ......... 54 ......... 43 
 
 510 ........ 277 ........ 174 ........ 119 ........ . 87 ......... 65 ......... 51 ......... 41 
 
 ......... 40 
 
 An inspection of these numbers must, I think, impress any one with the fact that it is 
 impossible to increase essentially the strength of cannon by a simple increase of thickness. 
 
 286. The weakness of a homogeneous cylinder, and the remedy, (which 
 will be considered in the following article,) have been mathematically 
 investigated, with great care, by Dr. Hart, of Trinity College, Dublin, 
 
 * Reports of Experiments on Metals for Cannon ; 1856. 
 
 t "The Practicability of Constructing Cannon of Great Calibre,' 
 
 &c. ; 1856. 
 
180 
 
 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 and Mr. C. H. Brooks, from whose calculations it has been illustrated and 
 made the subject of a paper by Mr. James Atkinson Longridge, followed 
 by an important discussion before the Institution of Civil Engineers. 
 Mr. Longridge says:* 
 
 If, in Fig. 137, A B C D represent a portion of a section of an 8-inch gun, of which A G B 
 is the inner, and D F C the outer circumference, the state of tension of any particle between 
 G and F may be denoted by ordinates drawn at the points in question, those above G F 
 representing tension, and those below compression. 
 
 If now the gun be of any homogeneous material, such as cast-iron, the state of tension at 
 the time of explosion, and when the gun is about to burst, will be denoted by a curve H I. 
 
 Fig. 137. 
 
 Hlustrating a strain on a homogeneous gun. 
 
 or II i, the former calculated according to Professor Hart, and the latter according to Pro- 
 fessor Barlow's formula. Then, supposing the tensile force of the material to be 12 tons per 
 square inch, and the thickness of the gun 64- inches, when the strain at G is G H, or 12 tons, 
 at F it is F 1 = 3 tons, or F i== If tons, according as the one or other formula is adopted. 
 The areas of these curves give the total strengths of the gun at the bursting point, and are 
 found to be 36.72 tons and 30.871 tons respectively, instead of 78 tons, which it would have 
 been if uniformly strained at 12 tons per square inch. 
 
 287. II. Hoops with initial tension to resist elastic pressure. This sys- 
 tem consists in making a gun of concentric tubes by putting on each 
 successive layer, proceeding outward from the centre, with an initial 
 tension exceeding that of those below it, or so that each hoop or tube 
 shall compress what is within it. The inner layer is thus, in its normal 
 state, in compression, while the outer layer is in the highest tension. 
 
 Then, by the law illustrated in the foregoing paragraph, the inner 
 layer being in compression is able to sustain the first and greatest 
 stretch, and the outer layer, although stretched less by the explosion of 
 the powder, has already been stretched into high tension, and thus has 
 to do an equal amount of work. The intermediate layers bear the same 
 relations to the initial strain and the strain of the powder, so that, in 
 short, all the layers contribute equally of their tensile strength to resist 
 the strain of the explosion. 
 
 * "Construction of Artillery," Inst. C. E , 1860. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 181 
 
 ON LARGE CAST-IRON GUNS. 
 
 From tJie Army and Navy Journal. 
 
 The interest awakened by the previous extracts we have made from 
 the advance sheets of General Gillmore's report induces us to continue 
 them this week. We select the generaPs remarks on cast guns of large 
 size: 
 
 A safe and advantageous arrangement and distribution of the materials 
 of a large cast gun particularly of a rifle-gun to enable them to sustain 
 the successive strains and shocks to which they will be subject in firing, 
 is incompatible with the condition that the gun shall be composed of a 
 single piece of homogeneous nietal. With forged guns of good wrought 
 iron, like that from Salisbury, Connecticut, the case is somewhat different, 
 particularly if the workmanship be such that the piece will not first give 
 way at the welds. The greatest tensile strength and ductility of the 
 metal are both brought into action. In firing, the bore of the gun rap- 
 idly receives a permanent enlargement, within the limit of rupture. The 
 surrounding metal is thus placed under tension, and the piece strength- 
 ened to a certain extent. The further stretching of the bore, beyond 
 the power of the metal to bear, is thereby prevented. In a wrought-iron 
 gun there is very little enlargement of the bore after the first fifty rounds, 
 if fired with heavy charges. Such guns should first be bored a little 
 smaller about two-tenths of an inch than they are required to be, and 
 should then be fired with a few large charges, and re-bored to the proper 
 calibre. 
 
 The forces which act upon a gun, tending to destroy it, are due prin- 
 cipally to the explosive force of the powder, and the expansion of the 
 gun by heat. 
 
 In smooth-bore guns, the maximum force of the powder or, in other 
 words, the maximum pressure blowing out in front of the reinforce was 
 in consequence of the inadequate length of the latter. 
 
 It is known, from repeated experiments, that the distending strain 
 upoD the metal of a gun, at points equally distant from the muzzle 
 that is, within the same transverse circular section varies inversely 
 with the squares of the distances of those points from the axis of the 
 bore. Thus, at five inches from the axis, the strain upon the metal would 
 be about double what it would be at the distance of seven inches, or in 
 the ratio of 49 to 25. 
 
 If we suppose a cylinder to be made up of a great number of very thin 
 concentric cylinders, in a condition of initial molecular repose, then the 
 strain upon these several cylinders, due to any distending force equally 
 distributed over the inner surface of the inner one, would vary inversely 
 with the squares of their diameters. 
 
 Professor Treadwell illustrates this law of diminution in the following 
 manner: 
 
 "If we make a cylinder of 41 concentric hoops of equal thickness, 
 disposed one within "another, and exactly fitting, so that the particles of 
 each hoop shall be in equilibrium with each other, the diameter of the 
 largest being five times that of the smallest, then the force of each, 
 beginning with the innermost, to resist distension, will be represented 
 by the following numbers : 
 
 1000 444 250 160 Ill 82. 62 49 
 
 826 391 225 148 104 77 59 47 
 
 694 346 207 137 98 73 56 43 
 
 591 309 189 128 92 69 54 45 
 
 510 277 174 119 87 65 51 41 
 
 ...40 
 
182 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 There is another important fact deduced by mathematical calculation, 
 and sustained by experiments in both this country and Europe, viz: 
 that no increase of thickness, however great, can enable a homogeneous 
 cylinder to sustain a distending pressure from within, on each square inch, 
 exceeding the tensile strength of a bar of the material one inch square. 
 
 Hence it is useless to attempt to augment the strength of a gun by 
 increasing its thickness beyond a certain point, " because," as Captain 
 Blakely remarks, "in cast guns (whether of iron, brass, or other metal) 
 the outside helps very little in restraining the explosive force of the 
 powder tending to burst the gun, the strain not being communicated to 
 it by the intervening metal. The consequence is that, in large guns, 
 the inside is split ivhile the outside is scarcely strained. This split rapidly 
 increases, and the gun ultimately bursts." 
 
 In other words, the exterior part of a homogeneous gun gives way to 
 forces applied by wedging and leverage, and not to a transmitted tensile 
 strain. 
 
 We see, therefore, how inadequately the hooping of old and nearly 
 expended guns accomplishes the object in view, of conferring upon 
 them additional powers of endurance, since the exterior hoop simply 
 reinforces metal that has not only never had its strength impaired by 
 use, but is not liable to be brought under any strain exceeding that 
 which it is well able to bear, except a splitting from the inside, which a 
 hoop can but feebly if at all restrain. 
 
 The only apparently effective way to utilize the strength of the exterior, 
 unimpaired metal of a cast gun in which cracks have already appeared 
 on the inside, is to replace a portion of the inside metal, throughout the 
 entire length of the bore, by a tube of tough and elastic material, placed 
 under slight compression by cooling the gun upon it. 
 
 Initial tension. We would conclude from the foregoing that if a gun 
 be compounded of several thin concentric hoops, or cylinders, those on 
 the exterior being under suitable initial tension, increasing according to 
 a fixed law with their several distances from the common axis, so that 
 the aggregate of the initial tension and transmitted strain, per square 
 inch on each cylinder, would be just equal to the tensile strength per 
 square inch bar of the metal, we would obtain a combination satisfying 
 the requisite conditions of maximum strength against statical pressure ; 
 for a distending force which would rupture the inner cylinder would 
 rupture all the others at the same moment. The greater the number of 
 cylinders, their aggregate thickness remaining constant, the greater 
 would be the strength of the combination. 
 
 Varying elasticity. Let us take another view of the case. If the 
 several thin cylinders be composed of metal possessing different degrees 
 of elasticity, decreasing according to a fixed law from the interior toward 
 the exterior, so that those on the inside would, by their greater elastic 
 expansion, transmit externally a distending strain of such intensity that 
 the metal of the several cylinders would reach the limit of elasticity at 
 the same moment, we would then have a combination of maximum stat- 
 ical strength, so long as the strain was not great enough to give the 
 metal a permanent set; that is, so long as the elastic limit was not 
 exceeded. When that point is reached, the advantages of varying elas- 
 ticity partially disappeared, and are replaced, in a measure, by those 
 of varying tension. 
 
 A cannon compounded of many concentric cylinders, combined on 
 either of the foregoing principles of initial tension or varying elasticity, 
 although possessing great theoretical strength, and although capable in 
 practice of sustaining great statical pressure from within, (great, indeed, 
 
EXPERIMENTS ON HEAVY ORDNANCE. . 183 
 
 in proportion to the number of cylinders used for a given aggregate 
 thickness,) does not possess sufficient unity of form to withstand the 
 repeated shocks of firing. While there must be, in some degree, a 
 division of parts, in order that the conditions necessary to resist statical 
 pressure may be imposed to a certain extent, there must also exist in 
 cannon the requisite continuity of mass and structure to resist the 
 instantaneous wave of force and other vibrations created in firing. 
 Cannon are seldom constructed of as many as four cylinders ; generally of 
 not more than two of three. 
 
 Captain Blakely has attempted to combine the distinct advantages 
 of varying elasticity and initial tension by using three tubes. The two 
 inner tubes are of steel, that possessing the greatest elasticity forming 
 the bore, while the outer tube is of cast iron, on which the trunnions are 
 cast. The tubes are shrank together, so that the outer one is under 
 slight initial tension. The elastic limit of the inner steel is thus favored 
 by bringing it under slight compression. Even should the steel tubes 
 become permanently strained, the gun, if properly constructed, would 
 not be weakened thereby, as the effect would be simply to increase the 
 tension upon the cast-iron jacket. Captain Palliser makes use of this 
 principlejin bringing his large guns under suitable tension on the exterior. 
 He makes the inner tubes of soft metal, the most ductile one containing 
 the bore, and then fires the gun with a charge that will permanently 
 stretch the inside. The gun is then finished by re-boring to the proper 
 calibre. Of course the exterior cylinder is thus placed under initial 
 tension. 
 
 Major Eodman, of the ordnance department, United States army, 
 recommends a method, now extensively followed, for placing the metal 
 of cast-iron guns under the proper conditions of initial tension, by cast- 
 ing them hollow and cooling them from the inside ; a process which is 
 inapplicable to steel guns, which have to undergo annealing. 
 
 In 1856 Professor Treadwell proposed a method of "constructing can- 
 non of a large calibre," of several tubes, the inner one, containing the 
 breech, being of cast iron about half a calibre in thickness. Upon this 
 he placed "rings or hoops of wrought iron, in one, two, or more layers," 
 by screwing them on. For that purpose a screw or thread was cut upon 
 the exterior of the inner or cast-iron tube, and upon the interior and 
 exterior of the other tubeSj except the outside of the outer one. The 
 hoops are about one-thousandth part of their diameter less than the 
 parts they envelop, and are screwed to their places while hot, to secure 
 the proper tension. 
 
 Whether the tubes of a compound gun should be put together on 
 Professor Treadwell's plan, with screws, or whether a more simple and 
 less expensive method of combination will .give the requisite unity of 
 form, is still a question of discussion. For reasons which will not be 
 given here, it is believed that screws are unnecessary, especially if the 
 trunnions are placed upon the outer tube, as in the Blakely and Whit- 
 worth guns. 
 
 Uffects of heat. The heat generated by the burning charge induces 
 or increases compression on the inside and tension on the outside of a 
 gun; and therefore, within certain undefined limits, strengthens the 
 piece against a distending strain. Another kind of strain is brought 
 upon the exterior of the gun by the expansion of the bore longitudinally. 
 Against this, a gun composed of two or more tubes can accommodate 
 itself with less danger of injury to the exterior than if made from a single 
 piece of metal, for the interior tube, instead of forcing the exterior to 
 elongate with it, or yield to rupture, slips through it. 
 
184 EXPERIMENTS ON HEAVY QRDNANCE. 
 
 The composition of the armament of land batteries for channel defence, 
 in the present condition of the great question of ships against forts, 
 should, of course, have special reference to the defence against armored 
 vessels. The best proportion for the two kinds, rifles and smooth-bores, 
 the most advantageous calibre for smooth-bores, whether large or medium 
 size, or a mixture of both, are questions upon which a diversity of opinions 
 exist among military and naval men. The invention of a large gun of 
 12 or 15 inch calibre sufficiently strong to be used effectively as a rifle, 
 and rifled in such a manner as would not impair its qualities as a smooth- 
 bore, would be a great advance in artillery. With such a gun heavy 
 elongated projectiles would be used with comparatively low velocities, 
 at either long or short range, for their smashing effect upon armor, while 
 solid steel or cast-iron spheres, and bolts and long percussion shells at 
 high velocities, would be very destructive in cutting and punching 
 through armor, and also upon the men and guns and machinery inside. 
 
 Batteries for channel and harbor defence should contain some but 
 in what proportion I am not prepared to suggest of the largest calibres 
 that can be manoBuvred with ease and rapidity. For cutting through 
 unimpaired armor at short range, in order to reach vital parts within as 
 quickly as possible, smaller calibres are better, as they will stand greater 
 relative charges and yield higher velocities safely. 
 
 EFFECT OF SIZE OF MASS ON STRENGTH AND TEXTURE OF CAST-IRON. 
 
 Extract from Mallett on Artillery. 
 
 SECTION 24. It is known to every practical iron-founder upon a large 
 scale that generally the larger the mass of casting he makes with any 
 given quality of cast iron the " coarser is the grain? that is, the larger are 
 the crystals that develop themselves in the mass. 
 
 SEC. 30. That the lower the temperature at which the fluid cast iron 
 is poured into the mould, and the more rapidly the mass can be cooled 
 down to solidification, the closer will be the grain of the metal; the 
 smaller its crystals the fewer and least injurious the " planes of weakness," 
 and the greater the specific gravity of the casting cceteris paribus. 
 
 SEC. 50. Slow cooling develops a coarse, uneven grain, with large but 
 thoroughly irregular and confused crystallization. Cast iron with such 
 a grain is never strong or cohesive, though, perhaps soft and extensible. 
 The more rapidly a casting once consolidated can be cooled, without 
 introducing injurious effects, the finer, closer, and more even will be its 
 grain on fracture, and with any given metal the greater will be its 
 strength. The rate of cooling cannot be accelerated beyond a moderate 
 limit. If this limit be exceeded, as by casting in a cold, thick, highly 
 conducting metallic mould, the iron is "chilled," its chemical or at least 
 its mixed constitution changed, and the uncombined graphite is exuded, 
 the combined carbon only remaining in the white chilled metal. It can- 
 not be so fast as to endanger unequal contraction, nor must it be so fast 
 in large castings, such as guns, requiring to be a fed" from a " feeding 
 head" with fresh portions of hot fluid metal during consolidation to fill 
 up the internal cavities or porosity due to contraction and crystallization, 
 as already explained, that this feeding cannot be accomplished. The 
 prevalent notion, however, that the soundest and strongest castings are 
 obtained by letting them cool slowly in the moulds is founded on a radi- 
 cal error. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 185 
 
 RELATION OF SIZE OF MASS TO STRENGTH AND TEXTURE OF WROUGHT 
 
 IRON. 
 
 Extract from Mallett on Artillery. 
 
 SECTION 213. We have found that the effect of large increase in the 
 mass of wrought iron, in connection with its necessary or exisitiug modes 
 of manufacture, is to prevent by process any regular or uniform arrange- 
 ment of its integral crystals; that as such masses are necessarily 
 continued long heated while forging, occupy long in cooling, and con- 
 tract considerably in all their dimensions in cooling, so the crystals are 
 developed to a large size and become arranged to a greater or less 
 extent in directions transverse to the surfaces of external contour of 
 the mass. 
 
 The results are irregular " planes of weakness," reduction of ultimate 
 strength to resist a quietly and steadily applied tensile force of from 20 
 to 17, or in very large masses of from 5 to 4 in round numbers, and reduc- 
 tion of resisting power to such impulsive forces as are concerned with 
 artillery in the ratio of from 7J to 1, or probably even more; for a train 
 of difficulties are introduced in the manufacture, and of injuries done to 
 the chemical qualities of the material, in proportion as we continue to 
 increase the magnitude of the mass to be forged. 
 
 SEC. 214. When the mass exceeds a very moderate bulk (in breadth 
 and thickness) the processes of rolling, &c., are at an end; those of forg- 
 ing by the tilt or steam-hammer alone are available. Skilled labor and 
 all the mishaps to which the results of the most adroit workmanship are 
 exposed in dealing with the heating and hammering of vast and scarce 
 manageable masses are inevitable. The mass must be gradually built 
 up and aggrandized in size by continual welding on to it of small pieces, 
 involving reiterated heating and partial cooling ; exposure for weeks, 
 perhaps, to a temperature at which the exterior of the mass gets changed 
 more or less in chemical constitution, and at each welding the risk of 
 inclusion of more or less slag, cinder, or other foreign matter. 
 
 Late experience has shown me that in very large cyliiidric masses of 
 forged wrought iron, (i. e., of three feet diameter and upwards,) amongst 
 the other abnormal circumstances involved in their production, is that 
 of their frequently* rending or tearing, internally, in planes nearly 
 parallel with and about the axis, though not always in it, presenting 
 characters similar to those described in section 217; and the cause 
 appears to be that in the progress of cooling of such a mass the exterior 
 cools first and becomes rigid, while the internal portions are still red-hot 
 and soft. The external parts would contract as they cool, but they 
 already grasp, in perfect contact, the still hot interior; the exterior, 
 therefore, cannot contract fully, but becomes solid under constraint cir- 
 cumferentially, partly itself extended in virtue of its compressing the 
 still hot and soft interior; the latter at length also becomes cold and 
 rigid, but its contraction is now resisted by the rigid arch of the exterior 
 with which it is surrounded. The contraction of the interior, therefore, 
 is limited to taking place radially outwards from the center, and thus 
 the mass rends itself asunder in some one or more planes parallel to the 
 axis of the cylinder. 
 
 In a cylindric mass of forged iron, varying from 24 to 36 inches in 
 diameter, rents of 18 inches in width across a diameter were found with 
 jagged counterpart surfaces clearly torn asunder, and about three-fourths 
 of an inch apart at the widest or central part; and the fact is most 
 instructive as to the enormous internal strains that must exist from like 
 causes in cast-iron guns and mortars of large size. 
 
186 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 It is probably from this cause that more or less hollo wness is found in 
 the centre of almost every large forging, greater in proportion as it is 
 larger. The difficulty is one not easily overcome; very slow, and, as far 
 as possible, uniform cooling of the whole mass in an annealing oven sug- 
 gests itself as one; but this has disadvantages in enlarging the crystal- 
 line development of the metal, or providing a central cylindric opening 
 so as to cool both the circumference and the center together. 
 
 EFFECT OF RE-MELTINGS ON THE STRENGTH AND TEXTURE OF CAST- 
 IRON. 
 
 Extract from Nallett on Artillery. 
 
 SECTION 25. The experiments of Mr. Fairbairn (Trans. Brit. Ass., 1853) 
 on the repeated melting of the same cast-iron, by casting into inch 
 square bars, are concluded by him to prove that the grain of the metal 
 and the physical qualities of the casting improve by some function of 
 the number of meltings, and he fixes on the 13th melting as that of 
 greatest strength. 
 
 EFFECT OF HEAT ON GUNS. 
 
 Extract from Mallett on Artillery. 
 
 SECTION 89. Applying Professor Hodgkinson's experimental results 
 as to the extensibility of cast-iron under strain to this reasoning, and 
 taking the coefficient of expansion by heat for cast and wrought-iron as 
 the same for low temperatures, (strictly as 1000893, 1000894 for tempera- 
 tures under 212,) we have the extension for cast iron for the square 
 inch of section equal about 3^0 -Q of its length for each ton of load, up to 
 seven or eight tons, at which its elasticity becomes permanently im- 
 paired ; that is to say, when it begins to lose its form. An equal change 
 of length is due to eight degrees of Fahrenheit difference in tempera- 
 ture. 
 
 SECTION 90. Let us now assume a 64 pound shot rammed home at 
 2,000 Fahrenheit, which is under a Avhite heat, and that it remains 50 
 seconds in the gun while the latter is being run out and fired; that in 
 this interval the shot transmits T ^ of its heat to an equal mass of the 
 cold gun, and that the whole of this is operative in expanding a cylin- 
 dric ring of a determinate thickness around the ball, then we have 
 
 F=^ =25 tons, 
 
 as the mean compressive strain per square inch upon this interior ring. 
 But as the ultimate cohesion of cast iron does not exceed about eight 
 tons to the square inch, the actual effect upon the strength of the gun is 
 the same, as if about three inches of its thickness were removed, or that 
 an inch in thickness of its interior metal were removed, and a total strain 
 of 17 tons were at the same time visited upon the remaining section of 
 its thickness. At such a conjuncture, with such a steady strain already 
 on its metal, the gun is fired and an additional impulsive strain, equal 
 to the work done in giving to the shot its initial velocity, is suddenly 
 brought upon its material. 
 
 This, even with the regulation reduced charge for hot shot, of J the 
 service charge for cold shot, is seldom less than 2J tons on the square 
 inch of section, producing from the impulsive nature of the force an 
 extension equal to that of a passive strain of 5 tons. The wonder, then, 
 is rather that any gun stands than that many should burst. 
 
 SECTION 93. A train of effects, quite analogous to those described, 
 
EXPERIMENTS ON HEAVY ORDNANCE. 187 
 
 are brought into operation in very quick firing, whether with hot or cold 
 shot, when the interior of the gun, continually receiving fresh accessions 
 of heat from the rapidly succeeding flashes of powder, is not given time 
 to transmit it by conduction through its metal to the exterior. The 
 limit of the heat that could be conceived communicated from one dis- 
 charge to the gun, would be the whole of that generated by the igni- 
 tion of the charge. Assuming the formula for gunpowder to be K O, 
 NO5+S-I-C3, its atomic weight will be 135, and one part by weight will 
 include 0.1333 of carbon. Now, Andrews (Keports Brit. Assoc., 1849,) 
 found that one part of carbon evolves as much heat in burning as will 
 raise an equal weight of water 7900 Cent. Hence, neglecting the sul- 
 phur as not oxidized in combustion, the heat generated by the firing of 
 any charge of powder is sufficient to raise the temperature of an equal 
 weight of water 7900 x 0.1333=1053 Cent.=1895.4 Fahrenheit, or to 
 boil about nine times its own weight of water, or to heat about nine- 
 teen times (18.945 strictly) its weight 100 Fahrenheit. 
 
 SECTION 95. In this case (that of heating by quick firing) the interior 
 expansion is not almost limited, as in the former, to a ring in the imme- 
 diate neighborhood of the shot, but extends to the whole length of the 
 chase or bore, so that the whqje gun becomes lengthened by the " end 
 on" strain of its expanded interior. 
 
 THE MECHANICAL EQUIVALENT FOB HEAT. 
 
 Extracts from u Sketch of Thermodynamics? by P. Gr. Tait, M.A. 
 
 It is very remarkable that from the series of experiments agreeing 
 well with one another, which were made with this simple apparatus, 
 Joule deduced as the dynamical equivalent of heat (that is, of the heat 
 required to raise the temperature of a pound of water 1 F.) 770 foot- 
 pounds, differing by only about a quarter per cent, from the results of 
 his subsequent and far more elaborate determinations. The close agree- 
 ment of the results of successive trials was quite sufficient to justify 
 him in publishing this, as in all probability a very close approximation 
 to the desired value of the equivalent. 
 
 (It is curious that the mean of the valves deduced from Eumford's 
 and Colding's experiments, the two legitimate ones whose publication 
 preceded that of this result of Joule's, differs from it by only about 2J 
 per cent.) 
 
 36. Before leaving this part of our subject it may be desirable to com- 
 plete the enumeration of the results of Joule's direct experiments for the 
 determination of the mechanical equivalent, as they are certainly supe- 
 rior in accuracy to those of any other experimenter. 
 
 Kepeatiug in 1845 and 1847 his experiments on the friction of water, 
 but now by means of a horizontal paddle, turned by the descent of known 
 weights, he obtained results gradually converging, as in each successive 
 set of experiments extraneous causes of error were more completely 
 avoided or allowed for. The value of the equivalent deduced in 1847 
 from a great number of experiments with water was 781.5 foot-pounds, 
 and with sperm oil, 782.1. In the paper of 1845, we find his first specu 
 lations as to the absolute zero of temperature, or the temperature of a 
 body absolutely deprived of heat. The most interesting of his results 
 are, that the absolute zero of temperature is 480 Fahr. below the freez- 
 ing point of water, arid that a pound of water at 60 Fahr. possesses, in 
 virtue of its heat, mechanical energy to the enormous amount of at least 
 415,000 foot-pounds. Changes have since been shown to be necessary in 
 
188 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 these numbers, but they are comparatively unimportant. And it must 
 be regarded as one of the most extraordinary results of physical science, 
 that a pound of water at ordinary temperatures contains heat capable 
 (if it could be applied) of raising it to a height of at least 80 miles. 
 
 37. Finally, in 1849, Joule published the results of his latest and most 
 elaborate experiments, of which, after what has been already said, the 
 results only need be given : 
 
 From friction of water 772.692 foot-pounds. 
 
 " " mercury 774.083 
 
 " cast-iron 774.987 " 
 
 The conclusion of this valuable paper, after all allowance is made for 
 slight but inevitable losses of energy, by sound and other vibrations, 
 are thus given : 
 
 1st. The quantity of heat producedby the friction of bodies, whether solid 
 or liquid, is always proportional to the quantity of icorTc expended. 
 
 2d. The quantity of heat capable of increasing the temperature of a pound 
 of water (weighed in vacuo, and taken at between 55 and 60 ) by 1 Fahr., 
 requires for its evolution the expenditure of a mechanical force represented 
 by the fall of 772 pounds through the space of one foot. 
 
 It is only necessary to observe, that the determination is for the value 
 of gravity at Manchester, and must of course be diminished for higher, 
 and increased for lower latitudes, according to the well-known law. 
 
 38. As no one has yet pretended to rival in accuracy the experiments 
 of Joule above mentioned, and as his celebrated result of 1843, so very 
 close to the truth, preceded all other recent sound attempts to determine 
 the mechanical equivalent of heat, the results of direct methods since 
 employed by other observers may be passed over with the remark, that 
 
 they agree more or less perfectly with those of Joule. 
 
 * # # # * # * 
 
 87. The unit for measurement of work usually employed by British 
 engineers is the foot-pound; and though this varies in amount from one 
 locality to another, it is in such general use and so convenient when 
 absolute accuracy is not required that it will be employed throughout. 
 It is the amount of work required to raise a pound a foot high. It is 
 evident that to raise any mass to a given height the amount of work 
 required is proportional to the number of pounds in the mass, and also 
 to the number of feet through which it is to be raised. Thus, to raise a 
 hundred weight a furlong high requires the same expenditure of work 
 (73.920 foot-pounds) as to raise a stone-weight a mile high, or a pound 
 14 miles. And the potential energy of the raised mass, or the work 
 which can be got out of it in virtue of its position, is precisely equivalent 
 to the work which has been employed in raising it. 
 
 TIME AND TENSIONS EFFECT OF TIME ON TENSIONS. 
 
 Extracts from " Experiments on Metals for Cannon and Cannon Powder." 
 Rodman, p. 28. Report of Captain Rodman, January 30, 1867. 
 
 These results appear to leave no doubt as to the superiority of the 
 hollow over the solid cast guns, while new; what effect time may have 
 upon them can only be ascertained by experiments ; but it is difficult to 
 understand how time could ever so far change their relative endurance 
 
 as to cause the solid cast guns to surpass those cast hollow in this quality. 
 
 ******* 
 
 The only effect of time is supposed to be to relieve the metal from 
 the strain to which it had been subjected in cooling, it not being sup- 
 posed to effect any change in its actual character. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 
 
 189 
 
 It would, therefore, appear to be reasonable and safe to predict that the 
 utmost effect which time could produce would be to bring their endurance 
 to an equality ; and should this be found to be the case, which is not prob- 
 able, it would still leave the hollow cast gun superior to the other 5 as it is 
 believed that it may be mounted for service as soon as finished, and relied 
 on for at least 150 rounds, for 10-inch guns ; while the solid cast gun cannot 
 be relied on for a single fire when new ; nor can any limits, below which it 
 shall be safe, be with any degree of certainty assigned to it after any 
 lapse of time. 
 
 The cause of this difference is believed to be that the hollow cast gun 
 is so far relieved from strain in cooling as to remove the possibility 
 of its ever being injured in that process ; and the more perfect this relief, 
 the more nearly will the endurance of the new gun approach that of the 
 same gun after any lapse of time. 
 
 While in the new solid cast gun it is certain that the interior is under 
 a very heavy strain, which requires time for its removal ; and there is 
 no certainty that this strain has not been sufficiently great to produce 
 either actual cracks, or such a degree of molecular separation in the 
 interior portions of the gun as no lapse of time will remedy. 
 
 That good solid cast guns may be made is not doubted, for they have 
 been made ; but that it is possible to distinguish before the trial the 
 safe from the unsafe gun is not believed. 
 
 Report on the effect of time in removing strains caused by the unequal cooling 
 
 of heavy iron castings. 
 
 PITTSBURGH October 12, 1852. 
 
 SIR : Since my report of the 24th of January last, on the manufacture 
 and extreme proof of 8-inch and 10-inch colunibiads, Major Bell has com- 
 pleted the extreme proof of two 8-inch coluuibiads, cast in 1846. The 
 extraordinary endurance of these two guns induces me to submit some 
 further considerations upon the subject. 
 
 The mechanical tests and the endurance in firing of the three 8-inch 
 columbiads are as follows : 
 
 
 Density. 
 
 Tenacity. 
 
 No. of fires 
 endured. 
 
 Cast and proved in 1851 
 
 7 287 
 
 37 811 
 
 72 
 
 Cast in 1846 and proved in 1852 
 
 7.247 
 
 29, 423 
 
 2,582 
 
 Cast and proved in 1852 .. . . 
 
 7. 220 
 
 22, 989 
 
 800 
 
 
 
 
 
 The form, dimensions, weight, method of casting and cooling, and the 
 manner of proving, were the same in all. It will be seen that the gun 
 made of the strongest iron, with a short interval of time between its 
 manufacture and proof, endured the smallest number of fires $ and that 
 those made of weaker iron, but proved long after they were cast, endured 
 the greatest number of fires. This remarkable feature in these trials 
 suggests an inquiry as to the cause of such anomalous results. 
 
 In the former report, made in January last, the character and the 
 effects of the strains which occur in the cooling of iron, when cast in large 
 masses, are stated and discussed. But now it appears, from the results 
 obtained in the trials since made, that there is another question to be 
 considered ; that is, longevity of such strains, or the length of time during 
 which a body will remain under a strain, without a renewal of the strain- 
 ing force. 
 
190 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 It is assumed that any casting, or any other solid body will, if con- 
 stantly strained for a long time, adapt itself, in part at least, to its strained 
 position, and lose its power of voluntary restoration to its original posi- 
 tion. 
 
 Suppose, for example, that a proof bar of cast iron be strained in the 
 testing machine until its deflection is about two-thirds or three-fourths 
 of that which it will endure \vithout breaking, or ulitil the deflection 
 nearly reaches the point at which incipient molecular separation occurs, 
 and that the pressure be then removed ; it will be found that the bar 
 has acquired a small measure only of permanent set. But if pressure is 
 not removed, or if removed it be again applied, and be continued a long 
 time, it will be found that the bar has acquired a permanent set, nearly 
 equal to its deflection, and that its power of restoring itself to its original 
 position has been almost entirely lost. Its particles, it would seem, have 
 adjusted themselves to their new and constrained position, and become 
 free, or nearly so. It appears that they resist constraint and retain the 
 power of self-restoration for a short time only ; but if the restraint be 
 long continued, they gradually conform themselves to it, and become 
 passive and acquiescent. 
 
 A bar which has thus been made to acquire a large permanent set, it 
 is believed, has lost but a small portion of its power to endure renewed 
 strains. It may be again pressed with a similar force, and acquire an 
 additional deflection and permanent set, nearly or quite equal to that 
 which had before been imparted to it. By repeating this process at long 
 intervals of time, the permanent set of a bar may be extended much 
 beyond the deflection which it was capable of enduring when it was first 
 strained. 
 
 Familiar examples of the facility with which bodies conform to con- 
 strained positions may be observed in the hoops of common barrels, 
 whether consisting of wood or of iron. The hoops, when first bent around 
 the barrel, lose but a small part of their power of restoration, but when 
 united at their ends, and driven firmly down upon the barrel, they soon 
 lose most of their active power of restoration, become passive, and acquire 
 a permanent set, conforming nearly to the circumference 011 which they 
 were strained. When they have thus acquired this permanent set, they 
 may be further bent upon smaller circles, until reduced to a curve which, 
 if attempted at first, would have broken them, while the strength of the 
 hoop will remain unimpaired. If solid bodies do thus relieve themselves 
 from strains produced by the application of an external force, why may 
 not a gun casting relieve itself in like manner from the strains caused by 
 unequal cooling ? 
 
 The strain produced in cannon by unequal cooling, as described in the 
 preceding reports, is one of compression on the exterior circumference, 
 and of elongation on the circumference of the bore. It may be likened 
 to the strain which would exist in a hollow cylinder, if the latter be cut 
 through its thickness in one of its elements, and the fissure be afterwards 
 enlarged by a mechanical force acting against the surfaces of the fissure. 
 A strain thus produced would obviously stretch the interior surface of 
 the cylinder, and compress its exterior surface. Now, if we suppose a 
 strain of this kind to be so far extended as to approach nearly to the 
 point at which incipient molecular separation occurs, any considerable 
 addition of a central force, of any kind, will evidently produce rupture. 
 This is, I believe, the condition of cannon when under a strain caused by 
 unequal cooling. And as the force of fired gunpowder acts in the same 
 direction, a few fires, if made soon after casting the cannon, will be suffi- 
 cient to burst it. But if the same cannon be allowed a sufficient time 
 
EXPERIMENTS ON HEAVY ORDNANCE. 
 
 191 
 
 between the casting and proving', to free itself from strain, it will endure 
 a number of fires proportioned to the tenacity of the metal from which 
 it is made. What length of time may be required to free a gun from 
 strain can be ascertained only by experiment ; but it will doubtless be 
 found to be proportioned to the hardness and tenacity of the iron, and 
 to the bulk of the gun. Hard, strong iron, contracts most, and conse- 
 quently is most strained, and will require the longest time to relieve 
 itself. 
 
 On this hypothesis, the results obtained in the extreme proofs given 
 in the preceding tables may be rationally accounted for. If we refer to 
 the 8-inch columbiads cast solid, we find that the one cast in 1851, and 
 proved in 30 days after it was cast, or say in about three weeks after it 
 had cooled, we find that with a tenacity of 37,811, it only endured 72 
 fires ; while of the two columbiads of the same model, cast in 1846 and 
 proved in 1852, more than six years afterwards, one of them, with a 
 tenacity of 22,989, endured 800 fires, and the other, with a tenacity of 
 29,423, endured 2,582 fires, and remains unbroken. 
 
 Results so remarkable cannot be accounted for in any other way, that 
 I can conceive, than on the assumed hypothesis before mentioned, viz : 
 that large iron castings, when cooled from the exterior, are unavoidably 
 strained in cooling, and that such strains, if within the limits of incipi- 
 ent rupture, are removed by time, leaving the casting free. 
 
 The method of cooling from the interior, devised by Lieutenant Eod- 
 man, tends to prevent injurious strains in cooling ; and if the method be 
 sufficiently extended on this principle, a strain in the opposite direction 
 may be produced. The strain, in this case, would be one of compression 
 on the surface of the bore, and of elongation on the circumference of the 
 gun ; and the tendency of such a strain would be to prolong the endur- 
 ance of the gun beyond the proportion of fires due to the tenacity of its 
 metal. 
 
 This theory of the effect produced by time in removing strains caused 
 by the unequal cooling of iron castings, appear to be so well sustained 
 by the facts exhibited in the experiments cited, and its bearing upon the 
 subject of casting heavy cannon appears to be so important, that I have 
 thought it my duty to state it, and to submit it to the department. 
 Eespectfully, your obedient servant, 
 
 W. WADE. 
 
 Colonel H. K. CRAIG. 
 
 THE RODMAN PRESSURE INSTRUMENT. 
 
 Extracts from " Experiments on Metals for Cannon and Cannon Powder." 
 
 Rodman, p. 197. 
 
 Table showing the velocity of shot, in feet per second, and pressure of gas per square inch, in 
 pounds, due to equal columns of powder behind equal columns of metal when fired in guns of 
 different diameter of bore, each result being a mean of lOJires. 
 
 "o 
 
 . 
 
 o 
 
 o 
 
 
 Pressure at different distances from bottom of bore. 
 
 
 
 I 
 
 ll 
 
 11 
 
 1 
 
 
 
 
 
 
 
 
 
 .5" 
 
 j9 
 
 '* 
 
 *> ** 
 
 V 
 
 At bottom. 
 
 At 14 in. 
 
 At 28 in. 
 
 At 42 in.' 
 
 At 56 in. 
 
 At 70 in. 
 
 At 84 in. 
 
 Q 
 
 ? 
 
 F 
 
 P 
 
 |> 
 
 
 
 
 
 
 
 
 In. 
 
 
 ids. 
 
 Lbs. 
 
 
 
 
 
 
 
 
 
 7 
 
 .07 
 
 5.13 
 
 74.44 
 
 904 
 
 36, 420 
 
 15, 850 
 
 8,370 
 
 6,470 
 
 6,850 
 
 8, 050 
 
 6,720 
 
 9 
 
 .09 
 
 8.48 
 
 124. 42 
 
 883 
 
 67, 100 
 
 21, 100 
 
 17, 759 
 
 14, 900 
 
 29, 475 
 
 20, 970 
 
 22, 825 
 
 11 
 
 .11 
 
 12.67 
 
 18G. 03 
 
 927 
 
 86, 750 
 
 29, 300 
 
 27, 800 
 
 22, 420 
 
 28, 400 
 
 33, 850 
 
 25, 050 
 
192 EXPERIMENTS ON HEAVY OKDNANCE. 
 
 The points most worthy of note in these results are the very marked 
 increase in pressure of gas as the diameter of bore increases ; and that 
 the indications of pressure are greater at 56 inches, 70 inches, and 84 
 inches than at 42 inches, especially in the 9-inch and 11-inch guns. 
 
 The cause of the difference in pressure developed in these guns of dif- 
 ferent diameters of bores is believed to be mainly due to the greater heat 
 developed by the combustion of the larger mass of powder in the large 
 than in the smaller calibre, and perhaps, also, to the different products 
 of combustion formed under this increased temperature and pressure, 
 and partly to the greater cooling surface in proportion to the weight of 
 charge in the small than in the larger calibre. 
 
 UNCERTAINTIES AND INCONGRUITIES CONNECTED WITH THE FABRI- 
 CATION OF GUNS. 
 
 Extracts from report of Captain J. T. Rodman experiments on metals for 
 cannon and cannon powder. 
 
 This investigation is ordered as a probable explanation of the differ- 
 ence in endurance of guns cast and cooled in the same manner, made 
 from iron of the same qualities, treated in nearly the same manner, and 
 differing but slightly in quality in the guns themselves. Probability, 
 however, is not Jcnowledge^ but it is the most that can now be offered as 
 well upon this as upon many other points of equal importance. 
 
 We do not know, for example, what qualities of iron are necessary to 
 make the best gun ; nor, if we did, do we know how, from any of its ores, 
 constantly to produce iron which shall possess those qualities. 
 
 We do not know whether guns should be cast hollow or solid, nor the 
 proper rate of cooling for either mode of casting. 
 
 We do not know the best exterior model for guns, nor whether those 
 of large calibre should be made with or without chambers. 
 
 We do not knoie the effects of time upon the endurance of guns 
 whether they are better when new, or after they have lain unused for 
 any given length of time. 
 
 We do not know the maximum statical pressure due to a given weight 
 of powder and shot, nor how much the rate of combustion of the charge, 
 or the rate of application of the force, causes the bursting tendency to 
 exceed that due to the statical pressure. 
 
 We do not know the difference in endurance due to a given difference 
 in bursting tendency at each discharge, nor what weight of projectile is 
 equivalent in bursting tendency to a given weight of powder, nor the 
 difference in endurance due to a given difference in thickness of metal. 
 
 We do not know the difference in bursting tendency due to a given 
 difference in temperature of the same charge of powder at the moment of 
 ignition. 
 
 Nor do we know the proper constitution of charge in order to produce 
 a given velocity of projectile with the minimum bursting tendency of 
 the gun. * * * * * 
 
 There is no other known cause for any considerable difference, yet we 
 cannot with certainty announce this as the only cause, for a single result 
 is not conclusive ; and differences, almost if not quite as great, in the 
 endurance of solid-cast guns, have been found to exist, without any known 
 cause. 
 
 # * * * # * 
 
 The cascabel dropped off the solid-cast gun at the 761st fire, and a 
 number of cracks were discovered in the face of the muzzle after the 
 
EXPEKIMENTS ON HEAVY ORDNANCE. 193 
 
 1209th fire, some extending back three or four inches. These cracks 
 have not since increased, and are believed to be due to some accidental 
 cause, rather than to the regular deterioration of the gun from firing. 
 
 The cascabel dropped oif the hollow-cast gun at the 1,379th fire. All 
 the trunnions of both guns are slightly cracked at the junctions of the 
 guns and rimbases, the left trunnion of the hollow gun apparently the 
 worst. 
 
 There is a very marked difference in the interior appearance of the 
 two guns, the bore of the solid-cast gun being greatly more deteriorated 
 than that of the hollow-cast gun. 
 
 There are three cracks radiating from the interior of the first, and one 
 from that of the second vent, in the solid gun. Those from the first vent 
 are from two to three inches long, running in an almost transverse 
 direction around towards the first vent. 
 
 There are no cracks perceptible in the hollow gun. 
 
 Extract from the report ofi tlie Joint Committee on the Conduct of the War. 
 
 It is, therefore, of the highest importance to obtain, if possible, some 
 kind of heavy ordnance which shall not be liable to these objections. 
 The entire efficiency of an iron-clad vessel, costing the government hun- 
 dreds of thousands of dollars, may depend almost entirely upon the 
 character of the guns with which she is armed. In the words of the 
 Assistant Secretary of the Navy, "you might lose a battle by going into 
 action with a gun around which stood 25 men entertaining the idea all 
 the, time that it might burst." Considering the great cost of our iron- 
 clad vessels, and the importance of the results to be attained, by render- 
 ing them as secure and efficacious as possible, a few thousand dollars more 
 of expense would seem to be of but little moment, if it affords the only 
 means of reaching the end desired. The disastrous results attending the 
 bursting of a gun can be, to a greater extent, guarded against upon land 
 than at sea. In the latter case the loss of the vessel, with all on board, 
 may be the consequence, while the demoralization of the crews of the 
 other vessels similarly armed may lead to results almost, if not quite, as 
 disastrous. But, upon both land and sea, it is of the utmost importance 
 to obtain heavy ordnance of the most reliable character. 
 
 '''"# * * * * 
 
 The bursting of these guns is generally attributed to the explosion of 
 shells, prematurely, within the bore of the gun. The opinion of Mr. 
 Parrott, in regard to the cause or causes of premature explosion of the 
 shells, is as follows : 
 
 It has been a matter of much concern with me, and I would rather not make a gun than 
 have any accident occur. I ascribe the difficulty to the friction of the powder in the 
 shell itself. At first it was natural enough to ascribe the difficulty to bad shells, bad 
 castings, bad fuzes, &c. ; but, upon full trial, it appears above all question that the diffi- 
 culty arises from the powder exploding in the shell within the gun by friction, caused by 
 the striking of the powder against the inside of the shell. A 300-pounder shell is 10 inches 
 in diameter; a round shell of that diameter holds about three pounds of powder. My 300- 
 pounder shell holds about 17 pounds of powder. Now, when you fire a gun, and strike the 
 butt of a shell suddenly with the immense force of the cha r ge, there is a reaction of the pow- 
 der within the shell against the bottom of the shell, and if there is any roughness so as to 
 cause friction at the bottom, the powder will be exploded in the shell while it is within the- 
 gun., Thinking that to be the case, I have for a long time been endeavoring to coat the 
 inside of the shell with varnish or lacker, and I am able to do it with entire success. A 
 great many people were skeptical about it, and precautions have not been taken, in regard 
 to it, as quickly as they might have been. I now melt together rosin, tallow and brown 
 soap, forming a thin liquid mixture, and pour it into my shells and pour it out again, leaving 
 a coating on the inside which covers over the rough iron, and when that is done I find the 
 shells can be fired without premature explosion. 
 
 Rep. No. 266 13 
 
194 EXPEKIMENTS ON HEAVY ORDNANCE. 
 
 Some two months ago Captain Temple, one of the officers of this very fleet of Porter's, 
 came to the foundry and became aware of this fact. He had two 100-pounders on board his 
 vessel ; when he got back he found that his shells had no such coating, and he immediately 
 set to work and lined them with asphaltum, &c. He fired his guns 50 or 60 times each 
 during the engagement, and not a single shell exploded prematurely in his guns ; while in 
 some of the other vessels around him shells were exploded prematurely, and thrown out of 
 the guns in fragments. 
 
 That is so stated in a letter of his which I saw yesterday. 
 
 Be the cause or causes what they may be, the fact is that these guns 
 do burst while in action, with very disastrous results. 
 
 Extract from tlie testimony of Brigadier General George D. Ramsay before 
 the Joint Committee on the Conduct of the War, p. 12. 
 
 Q. I cannot myself see why it would not be easy to take a 100-pounder 
 Parrott gun, for instance, and a 100- pounder Kodm an, and subject them 
 to certain tests of powder and ball, and ascertain which is really the 
 most energetic gun, and which will stand the most charges. 
 
 A. There would be no difficulty about it, aH things equal. Some of 
 the Parrott guns have burst before Charleston. This, however, is ascri bed 
 'to various causes, one of which is the frequent explosion of the shell in 
 the gun, and the introduction of sand into the bore. 
 
 Q. That would be no evidence of the power and strength of the gun 
 when properly fired. 
 
 A. No, sir. 
 
 RATIO OF GOOD AND BAD GUNS. 
 
 Extracts from the report of Captain J. T. Rodman. Experiments on 
 metals for cannon and cannon powder. 
 
 Out of seven solid-cast experimental columbiads, one gun only proved 
 to be good. 
 
 Out of six hollow-cast columbiads, three were good, having been fired 
 1,500, 1,600, and 2,452 rounds respectively, and neither gun broken. 
 
 It is not deemed out of place here, in order to show the necessity of 
 further investigations into the properties of cast iron in its application 
 to the manufacture of cannon, to notice some facts in the history of gun- 
 founding in the country since 1849. 
 
 The very low endurance of the first pair (8-inch) of experimental guns 
 which were cast in that year was attributed to the inferior quality of 
 the iron of which they were made. Two years were spent in searching 
 after a better quality of iron, which was undoubtedly found, and in 1851 
 another pair of 8-inch guns was cast. The iron in this pair of guns has 
 a tenacity of near 38,000 pounds, while that of the iron in the first pair 
 was only between 27,000 and 28,000 pounds. 
 
 The solid-cast gun of the first pair burst at the 85th fire, and that of 
 the second pair at the 73d fire, the superior iron giving the inferior solid- 
 cast gun. 
 
 These results did not, however, destroy confidence in strong iron for 
 solid-cast guns, and the first pair of 10-inch guns was made from the same 
 lot of iron, and, with a tenacity of iron of 37,000 pounds, the solid-cast 
 gun burst at the 20th fire. This result weakened confidence in very 
 strong iron, and the tenacity was reduced. 
 
 In 1857, after guns of good tenacity had failed at the Fort Pitt, South 
 Boston, and West Point foundries, four out of seven guns offered for 
 inspection at the last-named foundry having burst in the proof, Mr. 
 Parrott, proprietor of the West Point foundry, one of our most experienced 
 
EXPERIMENTS ON HEAVY ORDNANCE. 195 
 
 gun-founders, cast his trial contract guns of iron, having a tenacity of 
 30,000 .to 32,000 pounds. One of these guns has endured 1,000 service 
 charges of 14 pounds powder, (800 rounds with shells and 200 with shot.) 
 
 The iron selected at that foundry, and from which the last five experi- 
 mental guns have been made, was of the same quality, and in the same 
 proportions, as in the guns last above referred to. 
 
 In 1858, after the failure, at the 169th fire, of the West Point experi- 
 mental gun made from this iron, Mr. Parrott condemned it as being too 
 high for heavy guns. 
 
 From this rejected iron was made the last pair, Nos. 362 and 363, of 
 trial 10-inch guns, at the Fort Pitt foundry, which have been fired 2,452 
 rounds each, the least charges fired being 14 pounds powder and one 
 solid shot, and neither gun broke. These guns have since been fired 
 1,000 rounds each, with 18 pounds of powder, and solid shot, and neither 
 gun got broken. 
 
 It should also be borne in mind that the proprietors of the West Point 
 foundry have control of the smelting furnace at which their gun-iron is 
 made; they ought, consequently, to have a more perfect knowledge of 
 the qualities and properties of their iron than those founders who are 
 dependent upon the market for their iron. 
 
 These facts to my mind are conclusive as to the fact that we are at 
 present far from possessing a practical knowledge of the properties of 
 cast iron in its application to gun-founding; and it is too much to 
 expect of private enterprise to take up and prosecute so intricate and 
 expensive an inquiry. 
 
 Extract from the testimony of Brigadier General George D. Ramsay before 
 the Joint Committee on the Conduct of the War. 
 
 Q. You have stated the tests to which these guns were subjected. 
 What reason is there for believing that these tests are satisfactory; 
 what reason have you for placing confidence in them ? 
 
 A. The reliability of the experiments, as shown by the endurance 
 of the guns. 
 
 Q. You think they are satisfactory? 
 
 A. Yes, sir; every effort has been made to render them so. 
 ****** 
 
 Q. You consider the Eodman gun the best gun now in use? 
 
 A. Yes, so far as guns made entirely of cast iron are concerned. 
 
 Q. What tests have been applied to the Rodman gun I 
 
 A. First, there is the preliminary test of ores, which embrace all the 
 scientific investigations deemed necessary. Castings from the ores 
 selected are tested for density and tenacity. Experiments have estab- 
 lished standards below which guns are not received. Then comes the 
 powder proof. The only proof to which guns were formerly subjected 
 was by using excessive charges ; but this was found to be objectionable, 
 and not reliable, as there was no assurance that after all the trials with 
 heavy charges the gun would not, as often happened, burst with the 
 ordinary service charge. Confidence was greatly impaired, and many 
 serious accidents from bursting ensued. I refer to guns cast solid. The 
 theory of Captain Eodman being undoubtedly correct, experiments were 
 made in order to verify or refute it in a practical manner. Several sets 
 of cannon of the same form and calibre were cast, part in the ordinary 
 method of casting solid and cooling from the exterior, and the same 
 number on Rodman's plan. These were fired alternately, alongside of 
 each other, with charges of powder and ball of the same weight and 
 kind, and continued until one or the other class of cannon gave way 
 
196 EXPEKIMENTS ON HEAVY ORDNANCE. 
 
 under the repeated firing. The result of these trials on several sets of 
 cannon showed conclusively a far greater endurance for the Rodman 
 gun, more than 300 per cent, greater than those cast in the ordinary 
 way ; that is to say, we could rely on getting as much firing from one 
 Rodman gun as from three guns cast solid in the usual way. Besides 
 this greater durability, the Rodman gun possesses the greater advan- 
 tage of reliability in use ; that is to say, being served without danger to 
 the men standing by it from bursting of the piece. 
 
 Q. The powder test is the test by powder and ball the service charge ? 
 
 A. Yes, sir ; and when a new kind of gun or ore is introduced, the 
 trial is 1,000 pounds. 
 
 MODELS OF aims. 
 
 Extract from the testimony of Brigadier General George D. Ramsay before 
 the Joint Committee on the Conduct of the War, p. 10. 
 
 Q. I understand you that this Rodman gun was shaped after the 
 experiments of Colonel Boinford, to ascertain where the greatest strain 
 would come? 
 
 A. Yes, sir ; but whether Captain Rodman had these in view when 
 he investigated the subject, (which investigation will be found in a work 
 of high reputation on experiments on metals for cannon and cannon 
 powder, by Captain Rodman,) I am not prepared to say. As to the 
 shape of the gun, Commander Dahlgren, in a letter to Secretary Floyd, 
 accused Captain Rodman of plagiarism, on the completion of his (Rod- 
 man's) 15-inch, and which led to a correspondence between these officers. 
 Rodman's gun conforms more in exterior shape to the columbiad than 
 the Dahlgren. 
 
 Q. Does the advantage of the Rodman plan consist in the fact that 
 the gun cast hollow with a stream of cold water poured through the 
 inside ? 
 
 A. Yes, as regards the casting. But the Rodman gun embraces more 
 than this the exterior form. Formerly guns were in their exterior 
 form a series of sections of straight lines, called reinforce, somewhat 
 analogous to the joints of a telescope when drawn out, but the Rodman 
 gun (which the witness illustrated by a diagram on a piece of paper) 
 gives a curved section. The thickness at the seat of the charge in cast- 
 iron guns is a little more than the diameter of bore, gradually tapering 
 to the muzzle. Some twenty years ago the late Colonel Boinford insti- 
 tuted a series of interesting and original experiments to determine the 
 expansive force with which fired gunpowder acts at different points along 
 the bore of the gun and with the view of ascertaining the requisite curve 
 of resistance; that is to say, at what points the metal received the 
 greatest strain, and consequently where the greatest thickness was 
 necessary. From these experiments the columbiad a gun so called 
 originated, and to which may be traced the French Paixhan gun. The 
 columbiads were originally made with chambers, and are now used for 
 shot and shell. Colonel Bomford did not pursue his investigation beyond 
 determining the above facts. These experiments satisfactorily show that 
 the greatest force of the charge is exerted on the part of the gun which 
 is situated in rear of the centre of the ball, and the force diminishes 
 rapidly as the ball moves forward from its orignial position. 
 
 Q. When was this investigation I 
 
 A. About 1843. It is understood that a French ofiicer, General Paix- 
 han, when on a visit to this country, was made acquainted with the exper- 
 
EXPERIMENTS ON HEAVY ORDNANCE. 197 
 
 iments of Colonel Bomford, and on returning home he introduced a 
 similar gun into the French service, the Paixhan gun, as a shell gun. 
 
 Q. Then I understand you the principle is an old one ? 
 
 A. Not the principle of cooling from the interior. 
 
 Q. The shape of the gun? 
 
 A. This shape of gun is yet somewhat a matter of contention. It 
 matters not what the shape of the gun is, within certain limits, if cast 
 on correct principles. 
 
 Q. Describe the Dahlgren gun and the Bodman gun, and its advantage 
 over the Rodman gun or coluinbiad. 
 
 A. The Dahlgren gun is cast solid and cooled from the exterior. The 
 diameter of the rough casting at the chase is much greater than that of 
 the finished gun ; the surplus metal is turned off into the lathe. The 
 Eodman gun and the columbiads are cast hollow and cooled from the 
 interior. The. advantages of one form of gun over another is an open 
 question, and it matters not, within certain limits, if the gun is cast on 
 correct principles, such as Rodman's, as before stated. But as to the 
 advantages of casting very heavy guns on Rodman's plan, the Navy 
 Bureau of Ordnance has shown its confidence in the method of having 
 them so cast at the present time. 
 
 Q. Has either one of those guns any advantage over the other in actual 
 use or practice ? 
 
 A. In practice the Rodman gun cast hollow, in my opinion, must have 
 decided advantages as to endurance; as to range, this will depend upon 
 the circumstances under which they are fired. 
 
 EXPERIMENTS AT SHOEBTJRYNESS. 
 
 From the London Times. 
 v 
 
 The late trials of the 15-inch American gun and the English rifled 
 mountain gun for the Abyssinian expedition have been full of interest. 
 The heaviest smooth-bore and the lightest rifled gun in England were 
 fired side by side. The experiments with the American gun have not 
 led to any desire on the part of English artillerists to adopt the system, 
 but we hasten to admit that the huge Rodman is a magnificent gun of 
 its kind, and shows a process in the manufacture of cast iron which 
 does the gallant officer who has devoted himself to that branch of artil- 
 lery science infinite credit. It is curious that both American and Eng- 
 lish pieces of heavy ordnance are showing signs of far greater endurance 
 than was foretold by their respective backers. When first the Rodman 
 guns were issued for service, 60 pounds of their service powder, what- 
 ever it may be called, was considered the highest charge that could be 
 fired from it with safety, and that only a few rounds. The English 9-inch 
 gun in the same manner was allowed only 150 rounds, with its battering 
 charge, and 400 rounds were named as constituting its probable life if 
 the whole 150 battering charges were to be used in it. Since then the 
 Rodman has been fired at Fortress Monroe with 100 pounds of powder, 
 and a like trial at Shoeburyness has shown that the feat can be repeated, 
 but we have yet to learn how often with the same gun. One of our 
 9-inch rifled guns has stood 1,043 rounds, 680 of which were with battery 
 charges, some as high as 50 pounds, and the gun, though much eaten 
 away in the interior, is still capable of offence. Two other 9-iuch guns 
 have been fired 500 rounds each with battering charges, and are still in 
 excellent condition. We do not consider our 13-inch rifled gun a success, 
 but it was fired several times with 100 pounds of strong English powder 
 without bursting, and when two shot struck near each other the second 
 
198 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 passed through the Hercules target, which is probably the stroDgest yet 
 constructed. 
 
 It is very necessary in the comparison of different artillery systems 
 to distinguish between the many different questions involved. In the 
 present almost international competition the principal questions are: 
 1st. Backing v. punching; 2d. Comparative penetration; 3d. Killed v. 
 smooth-bore guns; 4th. The material of which the, national ordnance is 
 to be made. The difference between gunpowder is hardly a question, 
 because, though ours is stronger than the American, we do not claim 
 any advantage in that respect, but rather the contrary, because quick- 
 burning powder is too severe on the gun. The name by which the Ameri- 
 can powder used in the late experiments is known to the United States 
 authorities is hardly settled yet, for there are many gunpowders in their 
 list, and though the present sample is not the largest mammoth powder 
 such as was meant when we were told that 50 pounds of it only equalled 
 in strength 35 pounds of No. 7 cannon powder, neither does it appear 
 to correspond with the size of grain laid down for this latter. It is 
 perhaps something between the two, and its name is still uncertain. 
 "American service powder" was the name used in contracting for it, 
 and "American service powder" it is, of a strength one-sixth less than 
 English powder for heavy guns, whatever may be its exact title. 
 
 No one at all acquainted with the subject can deny, in the face of all 
 experiments made throughout the world, that elongated shot are better 
 calculated for penetration than round ones, nor did the Americans deny 
 this when they first produced their heavy guns. They said that they 
 did not wish to perforate or "punch" targets, but to smash them to 
 pieces or "rack" them. Their ships were protected with "laminated" 
 armor, by which is meant armor composed of several one-inch plates laid 
 upon each other and plated together. This is a kind of structure easily 
 shattered, and even far more vulnerable to punching guns than solid 
 plates, or a lesser number of thicker plates. English constructors saw 
 no difficulty in building ships that could not be -racked by guns of the 
 power set forth in American publications, and the result of the late 
 experiments has proved the truth of the assertion. It was only at close 
 quarters and with charges of 60 pounds too much for continued firing, 
 according to their own authorities that officers were allowed to attempt 
 to penetrate a strong iron-clad ship'. The contest between the advocates 
 of racking and punching was hot, and we were unprepared for the vexa- 
 tion exhibited throughout the Unites States when it was found that 
 their cast-iron and even our steel shot fired from their gun failed to 
 penetrate the target. If penetration and not racking merely be now 
 claimed for their guns, the only points to be assured of are these. Is 
 the average strength of a 15-inch gun sufficient to enable their naval 
 and military authorities to authorize the employment of 100-pound 
 charges, and, if so, will the projectiles which they use hold together 
 long enough to get through when they strike? A steel shot with 1,500 
 feet of velocity will penetrate the 8-inch plate and Warrior backing. A 
 cast-iron shot mayor may not, according to the excellence of its material. 
 Probably, but not certainly, it will penetrate. Certainly neither of them 
 will perforate the Hercules. 
 
 It is very instructive to look back a little and see how short a time 
 has elapsed since the object of iron-clads was supposed to be the keep- 
 ing out of, shells. Mr. Whitworth T s achievement when he fired a steel 
 shell through the Warrior target rang through Europe, and now chilled 
 shells with oval heads have a power of penetration superior to that of 
 shot. The 9-inch gun sends its shells through the 8-iuch target, and we 
 
EXPERIMENTS ON HEAVY ORDNANCE. 199 
 
 know that no round shells from the 15-inch Rodman have a chance of 
 piercing it, whatever may be the success of their shot. And then, be 
 it remembered, this 15-inch gun weighs seven tons and a quarter more 
 than the English 9 inch. 
 
 Many honest inquirers who are watching the results of the trials may 
 say, " There is something very odd about this matter. What is the virtue 
 of the English gun that it can send its lighter projectiles with lighter 
 charges through a target that resists a far greater expenditure of ammu- 
 nition on the part of the American gun? Is it quite fair not to use 
 chilled shot or shells which are so cheap and strong in both cases?" It 
 is fair, and, indeed, it would be very unfair to the American gun to put 
 chilled projectiles into it, and estimate its force by their effect. One 
 chilled, or rather white iron shot, was fired from it at the 8-inch target, 
 and did least damage of the three hurled against it on the same day, as 
 would have been predicted beforehand by all who understand this not 
 very abstruse question. White iron projectiles are very brittle, and are 
 of little use unless they have sharp points and are driven point foremost, 
 which can only be done if the gun is rifled. 
 
 The range at 32 degrees elevation and with 100 pounds charge was 
 7,680 yards, the initial velocity about 1,538 feet a second; 1,600 feet a 
 second is a common velocity for smooth-bores, and much higher speed 
 has jDeen attained in the wrought-iron guns constructed some years ago 
 for the navy. The Rodman gun is probably too short to burn all the 
 powder before the shot leaves the muzzle, and a further increase of 
 charge would not give proportionate velocity. Sixty pounds gives 1,170 
 feet per second; 100 pounds only increases it to 1,538 feet; quite enough, 
 however, to force an entrance into any of our ships at present afloat, if 
 the range is short, and if the gun is fired at right angles to the side of 
 the ship. The least angle will affect your round shot more than the 
 pointed one, because the former will glance, while the latter digs in its 
 point and then turns at right angles to the target. This was well shown 
 on Thursday last, when an 8-inch shell from a converted Palliser gun 
 pierced the Warrior target at an angle of about 26 degrees, the weight 
 of the shell being 180 pounds, that of the charge 22 pounds. We hope 
 that many interesting experiments will yet be made with the American 
 gun, and we sincerely congratulate Major Rodman on the excellence of 
 his cast-iron, while we still adhere by preference to our own material, 
 which is still stronger, especially for rifled guns, because grooves in a 
 gun cast on Rodman's method would vitally affect its strongest part, 
 the interior. Let us pay every respect to a very formidable weapon, 
 but we can do so without crying down our own lighter but even more 
 destructive ordnance. We cannot admit 100 pounds to be a service 
 charge till the American War Office gives us a right to do so, and if the 
 15 inch gun is to be compared with our 9-inch, and exceptional charges 
 are to be burnt in the former, we can hardly be denied the right to put 
 a little extra powder into the latter. The 15-inch, with its service-batter- 
 ing charge, fails to penetrate the target which is pierced by the 9-inch 
 with such a charge that several hundred rounds can be fired without 
 destroying the gun. 
 
 From the roar of the Rodman to the tiny ringing voice of the mountain 
 gun is a great downward jump, but the little steel piece is soon to do its 
 duty in actual war, unless wise and peaceful counsels prevail at last in 
 Abyssinia. Steel, while treacherous in large masses, from the difficulty 
 of casting and working it equally, is a perfect though rather expensive 
 material for small guns, and has been wisely chosen for mountain service. 
 The carriage is also of steel, except the wheels, and nothing could be 
 simpler than its general construction. It stood the force of recoil very 
 
200 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 well generally, though the wheels suffered a little from the recoil of the 
 piece when fired at high angles of elevation. This niite of a gun, which 
 a man might easily carry in his arms, for it weighs only 150 pounds, sent 
 its pretty little 7-pound projectile 2,944 yards, or more than a mile and 
 two-thirds, with a charge of 6 ounces of powder and an elevation of 32 
 degrees. Such long range work is not, however, likely to be required of 
 it, but rather shrapnel practice at ranges up to 1,000 yards or less. At 
 500, 520, and 540 yards more than half the bullets in the shrapnel shell 
 struck a target representing a column of men. With half an ounce of 
 powder and the same elevation the projectile ranged 478 yards. The 
 recoil, which was very lively when full charges were used, was brought 
 under control by hobbling the carriage, a small rope being fixed from 
 the point of the trail to one of the wheel spokes. 
 
 The so-called 64-pounder gun, converted on Palliser's principle, proved 
 its value by sending its shells through the Warrior plates, breaking once 
 out of three rounds through the skin and setting the wooden backing on 
 fire. The charge was 1C pounds, range 500 yards. The 8-inch converted 
 gun did even more work at 70 yards range, at an angle of about 26 
 degrees to the face of the target. The first round at 30 degrees angle 
 set the target on fire, the second at nearly 26 degrees passed through all, 
 bursting just as it cleared the inner skin. Here are three instances of 
 the value of rifled guns. Shell-fire either penetrates the target opposed 
 to these comparatively light pieces, or sets the backing in flames. 
 
 Let us once more put the state of the case before our readers. The 
 smooth-bored gun, with its service-battering charge, and an expensive 
 steel shot, fails to damage seriously a target which the rifled gun, less 
 than tAvo-thirds the weight of its antagonist, penetrates with shells of a 
 cheaper material. With an increased but dangerous charge the smooth- 
 bore will probably penetrate the target with shot but never with shell. 
 The rifled gun can be used in broadsides, the smooth -bore only in turrets. 
 Given the same weight of rifled gun, the effect will be much greater. If 
 the material of which the guns are made be compared, we take the actual 
 results obtained at Charleston, and fearlessly assert the superior 
 strength of our ordnance, for the federal rifled pieces were declared by 
 General Gillinore to be unable to fire 500 rounds with charges of only 
 one- tenth the weight of the projectile. Our 9-inch rifled guns outlive 
 many more than 500 rounds with charges of about one-sixth the shot's 
 or shell's weight. These are not theories but facts, and if any opposing 
 facts can be urged in contradiction they are at least out of the bounds 
 of our present experience, and we shall be glad to hear them. 
 
 Such is the comparative power of the two systems of ordnance. The 
 positive power of the Kodman with the power lately fired is as follows: 
 With 50 pounds of powder its power is very low compared with its weight. 
 With 100 pounds it can penetrate the sides of any ship afloat in the 
 English navy, and the 8-inch target at 70 yards, the shot's energy being 
 about 153 tons per inch of circumference. This supposes that the pro- 
 jectile is of steel. Cast-iron may or may not break up according to its 
 quality. At 700 yards it would pierce the Warrior, Lord Warden, or 
 Bellerophon, but probably not the 8-inch target, certainly not the Her- 
 cules or Monarch, now on the stocks. Its powers at 700 yards are much 
 inferior to the 13-inch rifled gun with 100 pounds of English powder at 
 the same range, the difference being about 56 foot tons per inch of circum- 
 ference. At no range whatever would the American gun with 100 pounds 
 charge perforate the side of the Hercules. These calculations are based 
 upon Captain Noble's formula, (which is in use in other countries besides 
 England, Prussia for instance,) and upon the known strength of the 
 
EXPERIMENTS ON HEAVY ORDNANCE. 201 
 
 English targets. To complete the interest of the late experiments it 
 would be well that the select committee should try targets on the Ameri- 
 can system and one of Krupp's heavy guns. 
 
 RIFLED GUNS. 
 
 Extracts from the report of the Joint Committee on the Conduct of the War. 
 
 The proportion of rifle guns to those with smooth-bores used in the 
 navy is much smaller than those used in the army. The difficulty of 
 obtaining accuracy of fire upon a vessel in motion renders the rifled guns 
 less efficient Avhen used at sea than when used upon land. 
 
 The projectile from a smooth-bore, except within point-blank range, is 
 fired so as to ricochet upon the water, arid it continues its flight in a 
 straight line until it stops. The projectile from a rifled gun, when it 
 strikes the water, ricochets at an angle from the direct line, sometimes 
 
 almost at right angles, and it is therefore less reliable at long range. 
 
 ******* 
 
 The rifled gun of large calibre, employed almost wholly in the army 
 and naval service, is the gun invented by Robert 0. Parrott. It is com- 
 posed of a cast-iron cylinder with a wrought-iron jacket or band shrunk 
 upon the breech of the gun in order to strengthen it about the seat of 
 discharge. The cast-iron cylinder of this gun was formerly cast solid, 
 and then bored out ; but latterly those of the largest calibre are cast 
 
 upon the Eodnian principle. 
 
 * * , * * * * * 
 
 But the bursting of the Parrott guns of large calibre, together with 
 the bursting of some of the cast-iron guns of large calibre, upon the 
 vessels engaged in operations against the defences of Charleston and 
 against Fort Fisher, has tended to weaken confidence in the durability 
 of those guns, and would seem to show the necessity of obtaining, if 
 possible, some other gun which can be more implicitly relied upon. It 
 is the testimony of our officers of the navy that the bursting of one gun 
 in a fleet tends to demoralize the crew of each vessel upon which a gun 
 of that kind is used, whether it burst or not. And it is asserted that 
 the loss sustained by the bursting of guns of large calibre on vessels 
 operating against Fort Fisher was much greater than the loss sustained 
 
 on the entire fleet from the fire of the enemy. 
 
 ******* 
 
 In view of these considerations, your committee desire to refer some- 
 what at length to a wrought-iron gun which, to them, seems to possess 
 those qualities ot strength, durability, and safety which are so very de- 
 sirable. It is the invention of Horatio Ames. But few of these have 
 yet been manufactured, yet they have successfully withstood every test 
 that has been applied to them. 
 
 Upon the 21st of August last, at the request of the inventor, the Presi- 
 dent ordered the appointment of a board to test a gun of 7-inch calibre 
 
 manufactured by Mr. Ames. 
 
 ******* 
 
 As the result of the examination the board report : 
 
 It is the unanimous opinion of the board that Ames's wrought-iron guns possess, to a 
 degree never before equalled by any cannon of equal weight offered to our service, the essen- 
 tial qualities of great lateral and longitudinal strength, and great powers of endurance under 
 heavy charges ; that they are not liable to burst explosively and without warning, even when 
 fired under very high charges; and that they are well adapted to the wants of the service 
 generally, but especially whenever long ranges and high velocities are required. It is also 
 the unanimous opinion of the board that Ames's 7-inch guns, of which he has now 15 nearly 
 finished, possess sufficient weight and strength to receive an 8-inch bore and even greater, 
 although not heavy enough for a 10-inch bore. 
 
202 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 The opinion of Mr. Fox, the Assistant Secretary of the Navy, of the Ames's gun, and of 
 the necessity for some gun of that character, is thus stated by him in his testimony : 
 
 "I think it is a fair inference, from the experience we have had with the small guns and 
 100-pounders which he (Mr. Ames) has made, that he has the correct principle of manufac- 
 ture, and that guns manufactured by his method will bear any amount of charge that can be 
 consumed in the gun. * 
 
 "My opinion is that we have got to come to wrought-iron or steel guns and abandon cast 
 iron." 
 
 ********* 
 
 Extracts from the testimony of Brigadier General George D. Ramsay before 
 the Joint Committee on the Conduct of the War. 
 
 It may be said of the rifled guns that we were called upon to intro- 
 duce the rifled system in time of war, suddenly and without the facilities 
 for practical experiment. We have no government arsenal, or conve- 
 nient place adequate to proper trials for range, penetration, &c. There 
 is no place that I am aware of, under our control, for extensive land 
 range, and for that reason my predecessor recommended, at the last 
 session of Congress, the purchase of a tract of land near New York, on 
 the New Jersey marshes, for this purpose, and which presented an 
 uninterrupted and secure range of several miles. We have had a good 
 deal of practice with field and the 4 J- inch rifle guns at the Washington 
 arsenal, but necessarily over the water, rendering the experiments 
 unsatisfactory both as to ascertaining penetration, correctness of flight, 
 &c., of the projectiles, and of many other elements necessary in judging 
 of what constitutes a good rifle gun and a good projectile. 
 
 Q. Then you do not give any preference to the Rodman gun over the 
 Parrott gun, but are getting both as fast as you can f 
 
 A. No preference in orders given for guns is shown. We have been 
 and are getting both kinds as fast as we can. Unlimited orders have 
 been given to all the founders making guns. The entire capacity of 
 the country has been called into requisition to meet the demands of the 
 service. Everything has been done on the part of the government, so 
 far as I am advised. 
 
 Q. What proportion of our sea and land armament is of rifled ordnance, 
 and when were rifled guns introduced into service I 
 
 A. I should have to refer to the records to answer the first part of 
 your question ; as to the introduction of rifled ordnance, my first recol- 
 lection of them was at the battle of Bull Run. 
 
 Q. What proportion of the land ordnance is rifled, so far as you 
 know? 
 
 Q. With regard to the old guns forming a portion of the armament of 
 the fortification, we are now rifling every gun along the seaboard. 
 We are at this very moment rifling the guns at Portland, Portsmouth, 
 and Boston. The 24 and 32-pounders are simply rifled ; but to the 42- 
 pounders we are applying the wrought-iron jacket in addition upon the 
 Parrott principle, with the Parrott increasing twist. Experiments have 
 shown that the 24 and 32-pounders have sufficient endurance without 
 going to the expense of banding. 
 
 Q. The intention is to have all the guns rifled ? 
 
 A. Yes ; the old guns, to include the 42-pounders, not the Rodmans. 
 Some of them, the 8 and 12-inch, have been rifled for experiment. 
 
 Q. Does it not weaken ordnance to some extent to rifle it ? 
 
 A. Yes; to some extent; but we are enabled to make reliable rifled 
 guns, even from those originally smooth-bore, as, for example, a third 
 class 32-pounder gun, rifled by Captain Parrott, and fired with his own 
 projectile, 64 pounds (double the weight of the 32-pound ball) and with 
 
EXPERIMENTS ON HEAVY ORDNANCE. 203 
 
 six pounds of powder, withstood 1,000 rounds. This gun was not 
 banded ; its tenacity was not more than 16,000 or 20,000, the standard 
 being about 30,000 pounds. It is doubtful whether this gun, before 
 being rifled, would have shown greater endurance with its own proper 
 service charge with round ball. We consider a gun a good gun that 
 will stand 1,000 rounds. 
 
 Q. At what time did these rifled guns come into use I 
 
 A. We had several batteries at the first battle of Bull Eun ; and have 
 since then furnished them, with all the rapidity that the foundries could 
 supply them. We have taken all the smooth-bore guns out of the field, 
 and substituted rifled guns as fast as we could get them. At the battle 
 of Bull Eun we had a 2 T 4 ^-inch, that is, a 10-pounder battery, a 20-pounder 
 battery, and one 30-pounder gun, which was lost. 
 
 Q. Can you give us any description of what is called the Whitworth 
 gun an English gun? 
 
 A. The Whitworth gun is a wrought-iron rifled breech -loading gun. 
 It has a hexagonal bore. It is a very ingenious and beautifully made 
 gun. It is liable to get out of working order in its breech arrangements 
 from the peculiar construction of the screw, which requires very perfect 
 mechanism. This screw arrangement becomes foul by escape of gas, 
 and it is sometimes difficult to close the breech. There are also muzzle- 
 loading Whitworth guns. 
 
 Q. And the heating of the gun by firing would effect it, I suppose? 
 
 A. Of course. In the models all the breech-loading guns seem to 
 work very well ; but when you apply the principle to large masses of 
 metal it becomes difficult to make the parts work easily. 
 
 Q. What about the Blakely gun ? 
 
 A. That is made a little after the manner of the Parrott gun. I think 
 it has a jacket of wrought iron shrunk on it, commencing at the trunnions 
 and embracing the entire rear of the gun. 
 
 BURSTING OF PARROTT GUNS. REPLY OF MR. WIARD TO MR. PAR- 
 ROTT. 
 
 From the New York Evening Post, February 2, 1865. 
 
 To the Editors of the Evening Post : 
 
 The letter of Mr. Parrott, in your issue of Saturday last, seems to me 
 to be an effort to resuscitate confidence in guns and theories now ex- 
 ploded. Mr. Parrott attributes the bursting of his guns to the prema- 
 ture explosion of shells within the bore. Why does he not show this to 
 be the cause by a series of experiments, by bursting shells in the bore ? 
 I assert that he cannot burst even a 30-pounder in that manner, and 
 that a 300-pounder can be so burst is even more improbable, except 
 the gun has been heated inside by a succession of discharges fired 
 as rapidly as guns must be in the excitement and hurry of hot bat- 
 tle, where the duty of the gun is quite different from the " dress parade" 
 practice of the proving ground, where the greatest deliberation is the 
 rule. When large guns are fired rapidly the inner metal along the bore 
 is expanded in all directions by the successive increments of heat from 
 the flame of powder supplied at each discharge more rapidly than it can 
 be dispersed throughout the whole mass of metal in the gun or radiated 
 away from the surface of the bore ; the interior swells with exactly the 
 force it would exhibit to resist compression, straining the outside metal 
 to the extreme verge of its power to resist fracture. When in this state, 
 the explosion of the charge, the premature explosion of the shell, the 
 effort of the gun to divert the shot or shell as it recoils backward (the 
 
204 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 gun being elevated) on a plane different from the plane of the axis of 
 the bore or the direction of the shot, having the tendency to throw the 
 shot higher than it was aimed, or to depress the muzzle of the gun, 
 sometimes breaks the muzzle off as by the blow of a heavy sledge, the 
 gun being in a state of initial strain, may cause the fracture. 
 
 Mr. Parrott cannot account for the transverse fracture under the band 
 by the explosion of shells in the .bore. A 15-inch Rodman gun, cast 
 hollow, and -cooled from the interior to get initial tension, at Pittsburg, 
 a few months since, when nearly cold and ready to be removed from the 
 pit, split from end to end. The inner metal had been cooled by water 
 passing through the bore, while the outside metal retained a higher 
 temperature. The outside metal, cooled at a later time, shrunk upon 
 the inner metal like the tire upon a wagon wheel. The cast block was 
 about 16 feet in length, and the wall about 16 inches in thickness ; con- 
 sequently, the area of cross section ruptured was equal to 3,172 inches. 
 If the tensile strength of the metal was 30,000 pounds to the square inch 
 of section, the pressure bearing upon the inner metal was about 95,000,000 
 of pounds on each side, or a whole tension of 190,000,000 of pounds. 
 
 I frequently experiment with glass models of guns, which I have sub- 
 jected to a water pressure of 800 pounds to the inch of surface in the 
 bore. These are broken in many pieces by inserting a heated rod of iron 
 smaller than the bore in such a manner as not to touch the surface. 
 
 The great Mallet mortar, made of a series of rings held together by 
 six strong bolts, was disabled by the lengthwise expansion of the rings 
 breaking the bolts. 
 
 One of Blakely's guns, made with four bolts reaching from the trun- 
 nion ring to the cascabel, broke the bolts in the same manner.* 
 
 The inner tube of the Whitworth gun, shown in General Gillmore's 
 report, increased in length by the heat communicated to xit, and closed 
 the vent, being shown projecting one inch.t If the bands had been 
 fastened by screw-threads, as proposed by Professor Treadwell, and 
 recommended by General Gillmore in his book for the bands of the Par- 
 rott gun, it would not be an improvement ; the bands would part trans- 
 versely as did the breech of a 300-pounder Armstrong gun, in which the 
 breecii-piece was inserted by screw-threads within the principal rein- 
 force band abutting against the inner tube of steel, it was burst by 
 the lengthwise expansion of the inner tube, pushing out the whole 
 breech, breaking the reinforce band transversely!. Compare this ex- 
 ample with the Whitworth gun shown in General Gillmore's report, 
 and with those Parrotts that have failed at the breech, and see the 
 analogy. 
 
 The bursting of Parrott guns has also been attributed to the fail- 
 ure of the gunners to put the shot home. Colonel Rodman shows, by a 
 series of experiments by firing charges of powder in a shell, the heaviest 
 of which only half filled the chamber, that the greater the proportion of 
 volume of space to the volume of the charge, the less the destructive 
 effect upon the walls. And even if the effect of the vis viva of the gases 
 against the shot and the wall of the gun immediately behind the shot 
 were greater than the effect of the pressure, it would not account for 
 the transverse fracture or the blowing out of the breech; neither can 
 
 *At this round the four bolts gave way the four united being equal to a solid bar the 
 size of the bore. The rest of the gun was uninjured. * * * I had this gun re-made, 
 with four bolts of the best charcoal iron, but they, too, broke without injury to the tubular 
 part. Paper read by Captain Blakelcy before the United Service Institution, England; vol. 
 Ill, Journal. 
 
 t See Plate X, Fig. 1 
 
 t See Plate X, Figs. 3 and 4. 
 
 $ See Plate VIII. 
 
EXPERIMENTS ON HEAVY OEDNANCE. 205 
 
 this particular fracture be accounted for by the sand getting into the 
 bore, as in General Gillmore's practice on Morris island. For the same 
 reason, if the shot is projected toward the muzzle its vis viva cannot be 
 expended upon the breech. If the theory of unequal expansion from the 
 heat of firing is accepted, it completely explains all the phenomena, but 
 it also has this other effect it brings us to the conclusion that all our 
 guns have been erroneously made $ for if we fabricate a gun in the best 
 manner to resist the pressure of the powder, i. e., with initial tension, it 
 is in the worst state to withstand the unequal expansion. In 1862 I 
 advanced the same views I am herein advocating, but they interfered 
 with the patented plans of ordnance officers or others in intimate rela- 
 tions with our ordnance department, charged with the duty of procur- 
 ing all the guns of government, and hence have never received the 
 attention they deserve. I foretold that our guns would fail whenever 
 they " received a fair and regular trial of their powers of resistance to 
 the proper strains of actual service," which Mr. Parrott indicates very 
 strongly they have not yet been subjected to. 
 
 For guns that would smash " British and French iron-clads into eter- 
 nal smithereens," or annihilate Charleston, our foolish and fond people, 
 the tax-payers, would be willing to pay the hundreds of millions charged 
 to them, on that account. 
 
 It should be recollected that we have, perhaps, eighty heavy guns 
 (mounted in turrets) of which the carriages " for what is a ship but a 
 gun-carriage ?" says Admiral Dahlgren have cost about one million of 
 dollars each, and these guns are ordinarily capable of being fired only 
 once in fifteen minutes each, except as at the bombardment of Fort 
 Fisher, (where two out of eight failed from rapid firing fired on that 
 occasion one shot in three minutes from each gun.) The whole fleet of 
 turret iron-clads, during a bombardment, can at this rate fire but about 
 five shots a minute. 
 
 The Minnesota, it is said, can fire a shot from her fifty-two guns in 
 every thirty seconds of time each about one hundred shots per minute, 
 equal to five whole fleets of iron dads. , 
 
 The guns of our iron-clads have been long in service, and what have 
 they done ? One shot struck the pilot house of the Atlanta, doing some 
 damage ; one struck the stern of the Tennessee, but did not penetrate. 
 Where is the record of any other service ? We know that Fort Mc- 
 Allister was bombarded eight hours, inflicting but little injury to the 
 works ; and in an attack on Fort Sumter by nine iron-clads, last- 
 ing forty minutes, five of the nine were disabled. Our forces on Morris 
 island were balked of success for a whole campaign, under the skilful 
 and brave General Gillmore, for the want of guns ; 23* of those Parrott 
 bombards burst in the action ; and who will attribute the want of success 
 to any other cause? Yet Mr. Parrott writes you, regretting that Gen- 
 eral Gillmore " should undertake to assign limit to the endurance of his 
 guns." The last paragraph of Mr. Parrott's letter is most significant. 
 He says, " I well know that nothing stands in the way of real improve 
 ment, so much as attributing failures to a wrong cause." If " consid- 
 erations far beyond the interests or feelings of an individual" influence 
 him, let him now heartily assist the good work of opening up the busi- 
 ness of inventing and fabricating guns to outsiders, and no longer be 
 connected with that close corporation, the regulars, more familiarly 
 known by the soubriquet u West Point." 
 Eespectfully, 
 
 NOEMAK WIAED. 
 
 WASHINGTON, January 30, 1865. 
 
 * It has since been found out that more than 50 of this kind of guns burst on Morris Island. 
 
206 
 
 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 RELATIVE POWER OF ENGLISH AND AMERICAN GUNS. 
 
 [From the report of Captain R. H. Noble, royal artillery, to the ordnance select committee, 
 dated Woolwich, England, 27th August, 1866.] 
 
 Table giving the remaining velocities and "work" of spherical steel solid shot 
 fired from 15-inch and 11-inch guns. 
 
 Gun. 
 
 Charge. 
 
 Projectile. 
 
 Initial velocity. 
 
 At 200 yards. 
 
 At 500 yards. 
 
 At 1,000 yards. 
 
 s 
 
 tf 
 
 I 
 
 Q 
 
 Remaining 
 velocity. 
 
 > 
 
 Remaining 
 velocity. 
 
 cs 
 >. 
 
 bo 
 
 S f^ 
 
 'a .-S 
 || 
 
 Vis viva. 
 
 
 Lbs. 
 
 Lbs. 
 
 Inches. 
 
 Feet. 
 
 Feet. 
 
 Tons. 
 
 Feet. 
 
 Tons. 
 
 Feet. 
 
 Tons. 
 
 15-inch 
 11-inch 
 
 50 
 20 
 
 484 
 189 
 
 14.85 
 10.85 
 
 1,070 
 1,080 
 
 1,028 
 1,019 
 
 3,547 
 
 1,361 
 
 969 
 936 
 
 3,152 
 1,148 
 
 880 
 818 
 
 2,599 
 
 877 
 
 
 From this table we can approximately determine the effect of 15 -inch 
 and 11-inch steel projectiles. 
 
 Thus, assuming that the penetration* varies universally as the diame- 
 ter, and that it requires 2,642 tons of "work" on impact to send a steel 
 shot of 9". 14 through the side of the Lord Warden, the penetration of a 
 steel shot from the 15-inch gun will require a force represented by the 
 following proportion : 
 
 9.14 : 2,642 :: 14.85 : x and x = 4,292 tons. 
 
 It would, therefore, require a force of 4,292 tons to send a steel shot 
 14.85 inches diameter through the Lord Warden. 
 
 A glance at the last table shows that the 15-inch gun is unable to 
 accomplish this even at a range of 200 yards, and it is further very doubt- 
 ful whether this gun, fired with 50 pounds of powder, which is as heavy 
 a charge as it will stand, and a solid steel shot of 484 pounds, w^ould pene- 
 trate the side of the iron-clad ship Lord Warden, even were the muzzle of 
 the gun touching the armor plates of the vessel. 
 
 It is needless to remark that the 11-inch gun would be much less 
 effective. These conclusions go to prove 
 
 1st. That the 7-inch muzzle-loading rifled gun of 134 hundred weight, 
 fired with a solid elongated steel shot of 100 pounds, and charge of 25 
 pounds, is not capable of piercing the Lord Warden at any range. 
 
 2d. The same remark applies to the 100-pounder smooth-bore gun with 
 a spherical steel shot of 104 pounds and 25 pounds charge. 
 
 3d. The 9.22-inch rifled gun of 12 tons, fired with an elongated steel 
 shot of 221 pounds and 44 pounds charge, is capable of piercing the Lord 
 Warden up to a range of about 1,000 yards. 
 
 4th. That the same remark applies to the 10.5-inch gun of 12 tons, fired 
 
 * Vis viva has been given in foot-tons instead of foot-poimds, in consequence of the num- 
 ber of figures required to express the latter. 
 We 2 
 
 where 
 
 W= weight of shot. 
 v = velocity on impact. 
 g =the accelerating force of gravity. 
 
 By penetration is meant actual perforation through the plate, or the power of passing 
 through the plate. In the case of penetration into iron plates, the term indent has been used. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 207 
 
 with a solid elongated shot of 301 pounds and charge of 45 pounds, and 
 to the present 9-inch service gun of 12 tons. 
 
 5th. That the American sniooth-bore guns of 15, 13, 11, and 9-inch 
 calibre, fired with solid spherical steel shot, and the highest charges 
 which they will bear with safety, are not capable of piercing the Lord 
 Warden at any range whatever. 
 
 6th. This vessel could steam past batteries armed with the above 
 smooth-bore guns without suffering except from "racking" effect. 
 
 THE BELLEROPHON. ' 
 
 The trial of this target was of such an undecided character and of such 
 a comparatively mild form that it is difficult to obtain sufficient data 
 upon which to base any comparison between this vessel and other iron- 
 clads. The most severe blow it encountered was from the 10.5-inch rifled 
 gun with a spherical steel shot of 165 pounds and charge of 35 pounds, 
 the striking "work" being 2,472 tons. This shot failed to penetrate the 
 target, but we have no evidence to prove that the 10.5-inch gun would 
 not have penetrated with a charge of 50 pounds and striking "work" of 
 2,898 tons. 
 
 The Bellerophon is undoubtedly of a stronger construction than the 
 Warrior and Minotaur class, but there is no direct evidence to prove that 
 it is as strong or stronger than the Lord Warden. 
 
 We have seen that 75.4 foot-tons per inch of shot's circumference has 
 failed to penetrate the Bellerophon, but it appears that this force is quite 
 sufficient to penetrate this target when the plates are 5.5 inches thick 
 instead of 6 inches (rounds 949 to 952). 
 
 W^e have no evidence, however, whether 75 foot-tons per inch may not 
 be too much for a Bellerophon with 5.5-inch plates. If we assume that 
 this force is only sufficient for the penetration of 5.5-inch plates on a 
 backing and skin similar to the Bellerophon, the latter with 6-inch plates 
 would require a force of 89.6 foot-tons per inch, which is about what is 
 required by the Lord Warden. 
 
 The fact, however, of the 10.5-inch gun having failed to pierce this 
 target indicates that the American smooth-bore 15 and 11-inch guns 
 fired with solid steel shot, and the highest charges they are capable of 
 bearing with safety, would not penetrate it at any distance over 100 
 yards. This vessel, therefore, could pass batteries so armed without suf- 
 fering except by " racking." 
 
 THE WARRIOR. 
 
 We see from the table* that the 7-inch rifled gun is capable of piercing 
 the side of this vessel with a 100 pounds shot and 20 pounds charge, the 
 striking "work" being 1,374 tons, (round 1,018). 
 
 The effect of the 100-pounder gun would therefore be represented by the 
 proportion 
 
 6.91 : 1,374 : : 8.87 : a?, and x == 1,764. 
 
 The force, therefore, required to send a steel shot from the 100-pounder 
 gun through the Warrior would be about 1,764 tons, and we may assume 
 that any force under this would not produce the required effect. 
 
 Thus we find, round 972, that a shot from the 100-pcuuder struck the 
 Warrior with a force of 1,573 tons, but failed to penetrate. 
 
 * Appendix, page 38. 
 
208 - EXPERIMENTS ON HEAVY ORDNANCE. 
 
 In the same manner we can approximate to the force required to send 
 a shot from the 9.22-inch gun through the Warrior 
 6.91 : 1,374 : : 9.14 : x, and x = 1,813 tons. 
 
 The 9.22-inch gun could therefore send a steel shot through the War- 
 rior, provided the striking force were 1,813 tons. 
 
 If the shot, therefore, was 221 pounds weight, the necessary velocity 
 would be 1,087 feet, and if the gun were fired with its full charge of 44 
 pounds it would send an elongated steel shot of 221 pounds through the 
 Warrior at about 2,000 yards range.* 
 
 In the same manner, in the case of the 10.5-inch gun, we have the pro- 
 portion 
 
 6.91 : 1,374 : : 10.43 : a?, and x 2,074. 
 
 The 10.5-inch gun would therefore send its shot through the Warrior, 
 provided the striking force were 2,074 tons. 
 
 From this it appears that the Warrior is of weaker construction than 
 the Lord Warden, as the 10.5-inch gun failed to penetrate the latter with 
 a striking force of 2,898 tons. 
 
 In the case of the 15-inch American guns, we have the proportion 
 6.91 : 1,374 : : 1,485 : a?, and x = 2,953 tons. 
 
 From Table XII, it appears that the 15-inch gun fired with a spherical 
 steel shot of 484 pounds, and a charge of 50 pounds, would penetrate 
 the Warrior at any distance up to 500 yards, but would not do so at 
 1,000 yards. 
 
 In the case of the 11-inch gun we have 
 
 6.91 : 1,374 : : 10.85 : x, and x = 2,157. 
 
 And from Table XII, we find that the 11-inch gun fired with a solid 
 steel shot of 189 pounds and charge of 20 pounds would not penetrate 
 the Warrior at any range, not even if the muzzle of the gun were touch- 
 ing the armor plates. 
 
 From these considerations the following effects are probable: 
 
 1. The 7-inch muzzle-loading rifle gun of 130 hundred weight, with a 
 solid shot of 100 pounds, and charge of 25 pounds, is capable of piercing 
 the side of the Warrior up to a range of about 600 yards.t 
 
 2. The 100-pounder smooth-bore gun (9-inch) of 125 hundred weight, 
 with a solid spherical steel shot of 104 pounds weight and 25 pounds 
 charge, is not capable of piercing the Warrior at any distance over 100 
 yards. 
 
 3. The 9.22-inch rifled gun of 12 tons with a solid elongated steel shot 
 of 221 pounds and charge of 44 pounds is capable of piercing the War- 
 rior up to a range of 2,000 yards. J 
 
 4. The 10.5-inch rifled gun of 12 tons with a solid elongated steel shot 
 of 301 pounds and charge of 45 pounds is capable of piercing the War- 
 rior up to a range of 2,000 yards. 
 
 5. The American 15-inch gun of 22 tons with a spherical steel shot of 
 484 pounds and charge of 50 pounds is capable of piercing the Warrior 
 up to a range of 500 yards. 
 
 6. The American smooth-bore 11-inch and 9-inch guns fired with solid 
 sperical steel shot and their maximum charges are not capable of piercing 
 the Warrior at any range. 
 
 * At this range the projectile will strike at a certain angle corresponding to the angle of 
 descent, but with rifled projectiles this angle is very small, and may practically be neglected. 
 
 t The same result would probably occur with the present service charge for this gun, viz. 
 22 pounds, and shot of 115 pounds 
 
 t The same result would occur with the service 9-inch gun of 12 tons. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 209 
 
 7. This vessel could pass batteries armed with 15-inch guns, as above, 
 at a distance of 800 yards, without suffering, except by "racking." 
 
 THE MINOTAUR. 
 
 This class differs from the Warrior in having one inch of iron armor 
 plating substituted for nine inches of wood backing. 
 
 In the trial of this target an experimental powder named 2 A 4 was 
 made use of, and this accounts for the effects observed with the 10.5-iiich 
 gun. 
 
 It appears from Table XIV that when the ordinary service powder 
 was used the result was something the same as in the case of the Warrior. 
 The actual strength of these ships may therefore, in absence of direct 
 evidence to the contrary, be assumed to be equal ; but whether the wood 
 and iron, which, combined, form the mass of resistance, have been more 
 advantageously distributed in the construction of the Warrior than in 
 that of the Minotaur, is a separate question. 
 
 On the whole, it may be assumed that the remarks which apply to the 
 Warrior are equally applicable to the Minotaur and ships of her class. 
 
 THE HERCULES. 
 
 This target was by far the strongest ever tried at Shoeburyness, and 
 accordingly it received the most severe treatment. The preliminary 
 experiments were made with the 9".22^ 10".5, and 10" rifled guns of 12 
 tons, firing solid steel shot with very high charges. 
 
 It appears that rounds 1041, 1045 penetrated the 8-inch plate, and 
 forced the pieces into the 12-inch wood backing. Both these rounds 
 struck between two ribs ; 1045, however, met with more resistance than 
 1041, as it struck just over one of the horizontal plates; the armor plate 
 was thus supported in rear of the point struck by a rigid backing. An 
 8-inch plate unbacked requires 88.5 foot-tons per inch of shot's circum- 
 ference to just penetrate it;* it was to be expected, therefore, that the 
 above rounds should do so. 
 
 Rounds 1043, 1C 44, 1040, 1042, struck the 9-inch plate, which, if 
 unbacked, would require a fore of 112.1 foot-tons per inch of shot's cir- 
 cumference to penetrate it. 
 
 Bound 1044 was therefore the only shot which had sufficient force to 
 penetrate the plate, and this round struck both on a rib, and full on one 
 of the rigid backings; 1040 almost penetrated the plate, as although the 
 absolute indent was only 4.5 inches the piece of plate struck was almost 
 dislodged; 1042 ought to have done more damage than it did; probably 
 the steel was not of the best quality. 
 
 The target was subsequently tested by firing at it with the 13-inch 
 wrought-iron gun of 22 tons, using solid steel and chilled iron shot of 
 570 pounds with 100 pounds of powder. 
 
 The gun was at 700 yards from the target. > 
 
 The results proved that the target was impenetrable when struck fair, 
 although it was penetrated by a chilled shot which struck just above a 
 previous round.f 
 
 When it is considered that this target was only 18.2 feet x 8 feet x 4 
 feet, and that it received blows amounting in all to over 70,000 foot-tons, 
 it must be confessed it did its duty. 
 
 * With a hemispherical-headed shot. 
 
 t It is probable that this target would have been penetrated had the steel projectiles been 
 ogival-headed, as suggested on minute lti,025. 
 
 Rep. Ko. 206 14 
 
210 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 THE SMALL PLATE. 
 
 This target represented a wooden ship armor-plated, such as the 
 French Flandres, &c. 
 
 It appears that this class of iron-clad is not quite as strong as that 
 represented by the Warrior or Minotaur, which are iron vessels armor- 
 plated, and of course not nearly as strong as the Lord Warden or Bell- 
 erophon. 
 
 Thus the 10.5-inch gnu, with a striking "work" of 1,657 tons, pene- 
 trated the "small plate' 7 target; and we have seen that this gun would 
 require a striking force of 2,047 tons to send the same shot through the 
 Warrior. It is hardly fair, however, to take this round (850) for the 
 basis of a comparison with other guns, as it appears that the target had 
 been previously considerably shaken. 
 
 On the whole it may be assumed that vessels of the class represented 
 by the "small plate" target are something weaker than those represented 
 by the Warrior, and that the remarks which apply to the latter are 
 applicable to the former in a greater degree.* 
 
 THE 8-INCH TARGET. 
 
 This target, as before stated, was designed for the trial of various 
 descriptions of steel and chilled iron projectiles. 
 
 The guns used in this experiment were the 8 and 9-inch muzzle-load- 
 mg Woolwich rifled guns firing service charges. 
 
 The results of this practice are fully given in table XIY, in the appen 
 dix, and may be briefly summed up as follows: 
 
 1. The target was proof against all projectiles when tired at obliquely. 
 
 2. The target was not penetrated when fired at direct, except by the 
 Falliser chilled projectile having a head struck with a radius of L5 
 diameters. This projectile was therefore clearly the victor, but whether 
 ihis is owing to its being in the form of a shell or to its bursting charge, 
 
 ve have no direct results to show. 
 
 3. It is probable that had the wood and iron which compose the target 
 been differently distributed the resistance would have been greater. As, 
 liowever, the target was built for a special purpose, this was not one of 
 the conditions to be fulfilled. 
 
 4. It is proved that a pointed projectile of 7.92 inches in diameter 
 can cut a hole in an 8-inch plate provided it strike with the necessary 
 work . 
 
 5. As a rule these experiments coincide with previous trials, with the 
 exception of the Palliser shell, which penetrated. This projectile accom- 
 plished more than calculation would lead us to expect. Some further 
 experiments will be necessary to determine the value of fc for this form 
 of head. 
 
 The following table shows the probable distance at which various 
 guns, firing solid steel shot with full service charges, would penetrate 
 iron-clad ships at present (1866) in the service. 
 
 * This target is of equal if not superior strength to the Warrior, if struck on-the 5.9-inch 
 plates. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 211 
 
 APPENDIX E. 
 
 List of guns burst and disabled in the army and navy since 1861; preparal 
 from reports and evidence before the Joint Committee on Ordnance. 
 
 Navy Parrott 100 pounder rifle gun, No. 2, burst at the muzzle on the 
 steamer Hunchback, June 19, 1864. 
 
 Navy Parrott 100-pounder rifle gun, No. 4, burst at the reinforce, and 
 through the band in several places, on the steamer Westfield, October 
 31, 1862. 
 
 Navy Parrott rifle gun 100-pounder, No. 6, burst at muzzle and chase 
 on the steamer Mahaska, 1863. 
 
 Navy Parrott 100-pounder gun. No. 11, burst at the muzzle on the 
 steamer Commodore Barney, April 10, 1862. 
 
 Navy Parrott 100-pounder rifle gun, No. 18, cracked in rear of vent or. 
 the steamer Genesee, May, 1864. 
 
 Navy Parrott 100-pounder rifle gun. No. 21, burst at muzzle on Cim- 
 arroii, February 15, 1864. 
 
 Navy Parrott 100 pounder rifle gun, No. 24, burst from trunnion to 
 rear of band on the Paul Jones, July 18, 1863. 
 
 Navy Parrott 100-pounder rifle gun, No. 25, cracked in two places ar 
 vent on Sassacus, January, 1865. 
 
 Navy Parrott 100-pounder rifle gun, No. 29, burst by blowing off breech 
 on the Juniata, December 25, 1864. 
 
 Navy Parrott 100 pounder rifle gun, No. 44, burst at breech on Com- 
 modore Perry, June 17, 1864. 
 
 Navy Parrott 100-pounder rifle gun, No. 135, cracked at the vent, Forfc 
 Jackson, June 14, 1865. 
 
 Navy Parrott gun 100-pounder ; No. 141, burst at the breech, which 
 was blown out on the Mackinaw, December 26, 1864. 
 
 Navy Parrott gun 100-pounder, No. 149, cracked at the top of the bore 
 and around the breech on the Commodore Read, November 14, 1864. 
 
 A*rrny Parrott 100-pounder gun, No. 1,* burst through the breech, 
 band, and reinforce, to forward of the trunnions, on the revenue steamer 
 Naugatuck, called the Stevens' Battery, in the James river, during the 
 attack on Fort Darling, May 15, 1862. 
 
 Navy Parrott 100-pounder Parrott gun, No. 150, cracked at the venfc 
 on Commodore Read, November 14, 1864. 
 
 Navy Parrott 100-pounder rifle gun, No. 162, burst at the muzzle on 
 the Ticonderoga, November 14, 1864. 
 
 Navy Parrott 100-pounder rifle gun, No. 166, burst by blowing oft 
 breech off Fort Fisher on the Yantic, December 24, 1864. 
 
 Navy Parrott 100-pounder, No. 194, rifle, cracked through the vent 
 on the Maumee, June, 1865. 
 
 Navy Parrott 100-pounder rifle gun, No. 213, cracked at vent on the 
 Kansas, December 24, 1864. 
 
 Navy Parrott gun, 100-pounder, No. 233, cracked on the outside from 
 trunnion to band on the Osceola, June 15, 1865. 
 
 Navy Parrott 100-pounder rifle gun, No. 238, cracked on the outside 
 from trunnion to band on the Mendota, July 24, 1864. 
 
 Navy Parrott 100-pounder rifle gun, No. 262, burst at muzzle on Talla- 
 poosa, April 5, 1865. 
 
 Navy Parrott 100-pounder rifle gun, No. 283, burst on the Mohican, 
 December, 1864. 
 
 * It appears that this gun, although the first of its class, was put in service without being- 
 subjected to extreme proof. Its failure did not deter the ordnance department from pur- 
 chasing, subsequently, a large number of similar guns. 
 
212 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 Navy Parrott 100-pounder rifle gun, No. 311, burst into 10 pieces on 
 the Ticonderoga, December 24, 1864. 
 
 Navy Parrott 100-pounder rifle gun, No. 325, cracked through vent 
 on the Lenapee, February, 1865. 
 
 Navy Parrott 100-pounder rifle gun, No. 330, cracked through vent 
 on Lenapee, February, 1865. 
 
 Army Parrott 100-pounder rifle gun, No. 104, burst on Morris island 
 a section of the reinforce thrown off in front of the band. The gun burst 
 at the 216th round. 
 
 Army Parrott 100-pounder rifle gun, No. 21, burst by throwing off a 
 large piece of the reinforce in front of the band on Morris island at the 
 1,150th round. 
 
 Army Parrott 100-pounder rifle gun, No. 158, burst on Morris island 
 at the 256th round, a large piece of reinforce thrown off in front of the 
 band. 
 
 Army Parrott 100-pounder rifle gun, No. 19, burst on Morris island at 
 the 128th round ; a large piece broken off in front of band. 
 
 Army Parrott 100-pounder rifle gun, No. 161, burst on Morris island at 
 the 377th round ; the gun burst through breech and the band, and the frac- 
 ture extended forward in front of trunnions. 
 
 Army Parrott 100-pounder rifle gun, No. 53, burst on Morris island at 
 the 152d round; burst through breech, band, and reinforce to forward 
 of trunnions. 
 
 Army Parrott 100 pounder rifle gun, No. 157, burst, throwing off a 
 large piece in front of the band, at the 219th round. 
 
 Army Parrott 100-pounder rifle gun, No. 153, burst forward of the 
 band and to the chase in front of the trunnions, at the 138th round. 
 
 Army Parrott 100-pounder rifle gun, No. 66, burst in front of the band, 
 on Morris island, at the 331st round. 
 
 Army Parrott 100-pounder rifle gun, No. 95, burst at muzzle, on Mor- 
 ris island, at the 87th round. 
 
 Army Parrott 100-pounder rifle gun, No. 736, burst through band, 
 breech, and reinforce, to forward of the trunnions, at 514th round, on 
 Morris island. 
 
 Army Parrott 100-pounder rifle gun, No. 155, burst through breech, 
 band, and reinforce, to trunnions, on Morris island, at 126th round. 
 
 Army Parrott 100-pounder rifle gun, No. 97, burst through breech, 
 band, and reinforce, forward to trunnions, on Morris island, at the 439th 
 round. 
 
 Army Parrott 100-pounder rifle gun, No. 51, burst forward of the 
 band, beyond the trunnions, nearly half the length of the chase, on 
 Morris island, at the 214th round. 
 
 Army Parrott 100-pounder rifle gun, No. 154, burst by blowing off 
 breech, on Morris island, at the 38th round. 
 
 Army Parrott 100-pounder rifle gun, No. 66, burst in front of the 
 band, forward to front of the trunnion, and breech blown out, on Morris 
 island, May 9, 1864, at the 108th round. 
 
 Army Parrott 100-pounder rifle gun, No. 99, cracked on outside from 
 band, to forward of trunnions, at 6th round fired on Charleston, May 15, 
 1864. 
 
 Army Parrott 100-pouuder rifle gun, No. 14, burst in rear of trunnions 
 into eight pieces, and band into two pieces, on Morris island, May 19, 
 1864, at 1,100th round. 
 
 Army Parrott 100-pounder rifle gun, No. 156, burst in front of band, 
 at 13th round fired upon Charleston, May 27, 1864. 
 
 Army Parrott 100-pounder rifle gun, No. 100, burst in front of band, 
 on Morris island, June 6, 1864, at 226th round. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 213 
 
 Army Parrott 100-pounder rifle gun, No. , burst in front of band, 
 on Morris island, July 15, 1864, at 491st round. 
 
 Army Parrott 100-pounder rifle gun, No. 23, cracked outside from 
 band to trunnions, at 1,480th round, September 4, 1864. 
 Army Parrott 100-pounder rifle gun, No. 187, burst through breech 
 and reinforce, at 316 rounds, September 12, 1864. 
 
 Army Parrott 100-pounder rifle gun, No. 186, burst by blowing off 
 breech, at 31st round, September 13, 1864, on Morris island. 
 
 Army Parrott 100-pounder rifle gun, No. 162, burst into a large num- 
 ber of pieces, some of which were thrown out of the battery. The shell 
 at the charge which burst the gun, was thrown 4 r OOO yards, September 
 17, 1864, Morris island. 
 
 Navy Parrott 100-pounder rifle gun, No. 81, burst at breech and re- 
 inforce into many pieces, some of which were thrown a great distance. 
 The shell at time of bursting (883d round) reached Charleston from Mor- 
 ris island. 
 
 Navy Parrott 100-pounder rifle gun, No. 128, burst in front of band, 
 in service against Charleston, at the 914th round, November 14, 1864. 
 
 Navy Parrott 100-pounder rifle gun, No. 34, burst at muzzle used 
 against Charleston by army at 1,225 rounds, November 12, 1864. 
 
 Army Parrott 100-pounder rifle gun, No. 18, burst in front of band and 
 band injured; used against Charleston; burst at 454th round, November 
 15, 1864. 
 
 Army Parrott 100-pounder rifle gun, No. 67, burst through breech and 
 band. The band was broken into three pieces. The shell reached 
 Charleston from the gun in Fort Wagner at the round at which the gun 
 burst, November 15, 1864. 
 
 Army Parrott 100-pounder rifle gun, No. 190, burst all in rear of trun- 
 nions into many pieces, at the 102d round, in Battery Gregg, November 
 28, 1864. 
 
 Army Parrott 100-pounder rifle gun, No. 189, burst in front of band, 
 196th round; mounted in Battery Gregg, November 29, 1864. 
 
 Army Parrott 100-pounder rifle gun, No. 52, burst breech and rein- 
 force into many pieces, at 1,590th round; Battery Chatfield, against 
 Charleston. 
 
 Navy Parrott rifle trial giin, No. , burst at the 420th round, 15-pound 
 charges ; its calibre was 8 inches 150-pounder. 
 
 Navy Parrott rifle gun, No. 6, (150-pouuder, calibre 8-inch,) cracked 
 in action, on the monitor Patapsco. 
 
 Navy Parrott rifle gun, No. 40, (calibre 8-inch, 150-pounder,) cracked 
 in service, on the monitor Patapsco. 
 
 Army Parrott 8-inch rifle gun, 150-pounder, No. 36, burst by blowing 
 off the breech, at the 226th round, on Morris island. 
 
 Army Parrott 8-inch rifle gun, 150-pounder, No. 25, burst by blowing 
 off breech, at 230th round, on Morris island. 
 
 Army Parrott 8-inch rifle gun, 150-pounder, No. 5, burst at breech, at 
 the 227th round, on Morris island. 
 
 Army Parrott 8-inch rifle gun, 150-pounder, No. 8, burst at breech, and 
 reinforce, at the 522d round, on Morris island. 
 
 Army Parrott 8-inch rifle gun, 150-pounder, No. 4, cracked on the out- 
 side from breech to trunnion, at the 599th round, on Morris island. 
 
 Army Parrott 8-inch rifle gun, 150-pounder, No. 6, burst at breech, at 
 the 36th round, on Morris island. 
 
 Army Parrott 8-int?h rifle gun, 200-pounder, No. 3, burst at breech, at 
 272d round. Shell reached Charleston at the round at which the gun 
 gave way fired from Battery Chatfield October 1, 1864. 
 
214 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 Army Parrott 8-inch rifle gun, 200-pounder, No. , burst in breech., 
 band, and reinforce into many pieces, at the 1,063d fire mounted in Bat : 
 tery Gregg August 15, 1864. 
 
 Army Parrott 8-inch rifle gun, 200-pounder, No. 24, at 269th round 
 crack was seen on the outside from band to trunnion, the crack ex- 
 tended from the inside ; Battery Ohatfield, August 5, 1864. 
 
 Army Parrott 8-inch rifle gun, 200-pounder, No. 25, cracked 011 side of 
 breech outside and continued under bands to trunnion 578 rounds July 
 30, 1864. 
 
 Army Parrott 8-inch rifle gun, 200-pounder, No. 20, burst at breech and 
 cracked inside, at 1,457th round, July 23, 1864. 
 
 Navy Parrott 8-inch rifle gun, 150-pounder, No. 6, cracked at muzzle, 
 on Patapsco, July 22, 1863. 
 
 Navy Parrott 8-inch rifle gun, 150-pounder, No. 28, cracked on outside 
 around breech, rear of vent, on Shenandoah, February, 1864. 
 
 Navy Parrott 8-inch rifle gun, 150-pounder, No. 46, cracked in bore, on 
 monitor Onondaga. 
 
 Navy Parrott 8-inch rifle gun, 150-pounder, No. 59, burst in chase and 
 muzzle, on the Pequot, September 12, 1864. 
 
 Navy Parrott 8-inch rifle gun, 150-pounder, No. 60, cracked on outside 
 from band to trunnion, on Colorado, December 25, 1864. 
 
 Navy Parrott 8-inch rifle gun, 150-pounder, No. 61, cracked at vent, on 
 monitor Onondaga, April, 1865. 
 
 Navy Parrott 8-inch rifle gun, 150-pounder, No. 82, burst, piece of 
 muzzle blown off, on Susquehanna, June 15, 1865. 
 
 Navy Parrott 8-inch trial rifle gun, 150-pounder, burst at Castle Island, 
 at the 420th round 15-pound charges of powder. 
 
 Army Parrott 10-inch gun, 300-pounder, No. 1, burst at muzzle, at the 
 27th round, on Morris island. This gun was repaired by chipping off the 
 broken part, and burst again at the 37th round. 
 
 Army Parrott 30-pounder rifle gun, No. 193, burst forward of the band, 
 at the 4,606th round, on Morris island. 
 
 Army Parrott 30-pounder rifle gun, No. , burst in breech and band 
 into many pieces, at the 2,900th round, in Battery Gregg, May 15, 1864. 
 
 Army Parrott 30-pouuder rifle gun, No. 18, burst at muzzle, 401st 
 round, July 7, 1864. 
 
 Army Eodman 8-inch rifle gun ? burst December 4, 1865, at the 1,047th 
 round. 
 
 Army Rodman 8-inch rifle gun, No. 1, burst at the 80th round. 
 
 Army Eodman 12-inch rifle gun, burst on the 19th of February, 1868, 
 at the 470th round ; the gun split through the breech and reinforce for- 
 ward to within four feet of the muzzle. 
 
 Army Eodman 12-inch rifle gun, No. 2, has been fired eight rounds, at 
 Fort Monroe, and is reported injured. 
 
 Army Eodmau 12-inch rifle gun, No. , has been fired two rounds, at 
 Fort Delaware, and is reported as injured. 
 
 Navy 12-inch rifle, cast hollow on the Eodman system and rifled on 
 Mr. Parrottfs plan, burst at the 27th fire. 
 
 Navy 12-inch rifle gun, cast hollow on the Eodman system and rifled 
 on the plan of General Eodman, was badly cracked at the 16th round, 
 when firing stopped. 
 
 Navy 12-inch rifle, cast hollow and on the Eodman system and rifled 
 on the Atwater plan, burst at the 30th round. 
 
 Navy 15-inch gun, in the monitor Miantonomoh, rjored four inches too 
 deep. Condemnable, and to be replaced. 
 
 Navy 15-inch gun, No. 19, on the monitor Canonicus, at 351 fires " reports 
 contradictory.' 1 
 
EXPERIMENTS ON HEAVY ORDNANCE. 215 
 
 Navy 15-inch gun, No. 25, sold at auction for cracks in the vent, 9th 
 fire. 
 
 Navy 15-inch gun, No. 26, sold at auction for cavities in the chamber, 
 9th fire. 
 
 Navy gun No. 29, 15-inch, burst the Saugus. This gun split through 
 the breech, at Fort Fisher, at the 243d fire. 
 
 Navy 15-inch gun, No. 13, cracked in service, on the monitor Lehigli. 
 
 Short 15-inch navy gun, No. 24, surveyed and condemned December, 
 1865, from monitor Monadnock, after the 168th fire. 
 
 Short 15-inch navy gun, No. 27, surveyed and condemned December, 
 1865, from monitor Monadnock, after the 161st fire. 
 
 Navy 15-inch gun, No. 12, cracked at the vent at the 132d round, on 
 t&e monitor Onandaga. 
 
 Navy 15-inch gun, No. 14, cracked at the vent, on the monitor Onan- 
 daga, at the 96th round. 
 
 Navy 15-inch gun, No. 1, (trial gun,) burst at the 868th fire. 
 
 Navy 15 -inch gun, No. 34, reported to be in a doubtful condition after 
 fche 363d fire. 
 
 NOTE. Of the first 34 numbers of 15-inch guns procured for the navy 
 for use in the turrets of the monitors, 12 are burst or disabled. The 
 whole number of rounds fired from all these guns altogether has been 
 5,448, equal to 160 rounds per gun. 
 
 Navy 15-inch gun, No. 23, at 358 fires was reported to be in doubtful 
 condition ; it was mounted in the monitor Canonicus. 
 
 Navy 15-inch gun, No. 35, fired 131 rounds for proof, reported in 
 doubtful condition. 
 
 Navy 15-inch gun, No. 44, on the monitor Mahopac, split in the chase, 
 at the 85th round. 
 
 Navy 15-inch gun, No. 67, mounted on the monitor Puritan, cracked 
 about the vent at 102 rounds, and was sold at auction for old iron. 
 
 Navy 15-inch gun, No. 68, cracked in the vent at the 59th round, and 
 was sold at auction for old iron. 
 
 NOTE. Forty-two of the 15-inch guns purchased for the navy have 
 never been fired more than nine proof rounds. 
 
 Of 25 mounted in iroii-clads, which were fired an aggregate of 1,333 
 fires, equal to an average of 53 fires for each gun, four have been burst 
 or disabled. 
 
 SPONTANEOUS RUPTURE. 
 
 Navy 11-inch Dahlgren gun found cracked at Eeadiug foundry, before 
 the turning was completed, November 10, 1862. 
 
 Navy 11-inch Dahlgren gun cracked before the turning was com- 
 pleted, November 16, 1862, at Reading foundry, Pennsylvania. 
 
 Navy 11-inch Dahlgren gun cracked previous to its completion at 
 Sheading foundry, November 16, 1862. 
 
 NOTE. The inspector gravely attributed the premature rupture of 
 these guns to the swelling of the sand of the mould by heat. 
 
 Navy gun 15 inch, (no number and no date,) burst while cooling, at the 
 Fort Pitt foundry. 
 
 Army 15-inch Eodman gun, No. 404, made at Eeadiug foundry, burst 
 open nearly the whole length while in the lathe. The explosion of this 
 great gun was attended with a loud report equal to a six-pounder gun. 
 
 Army 15-inch Eodman gun, No. 419, cast at Eeading, Pennsylvania, 
 burst in the pit after the removal of the core barrel. 
 
 Army 15-inch Eodman gun burst in the pit at the Pittsburg foundry, 
 having split the whole length. 
 
216 EXPERIMENTS ON HEAVY ORDNANCE. 
 
 Two army Rodman 10-inch guns cracked in the lathe. 
 One army Rodman 10-inch gun, cast hollow and cooled from the. 
 interior, burst in the lathe. 
 
 MISCELLANEOUS. 
 
 Naval wrought-iron gun, 80-pounder, made at Reading by Syfert, 
 McManus & Co., was paid for February 8, 1864, the price being $5,607 86 
 for the forged block, to be finished at the Washington navy yard. While 
 being finished, a flaw in the bore and another in the left trunnion were 
 discovered. The gun was never submitted to test. 
 
 Two army Ames guns, 7-inch calibre, made of wrought iron, burst in 
 proof. 
 
 Army Ames gun, 7-inch calibre, bored out to eight inches, burst at 
 Fort Monroe, at the 26th round, after the enlargement. 
 
 Army Rodman gun, 13-inch calibre, burst on the 27th July, 1864, at 
 the 738th round. The gun broke through the breech and reinforce into 
 a number of pieces. 
 
 Navy Ericsson's 13-inch smooth-bore wrought-iron gun, made at a cost 
 of $30,000, and paid for previous to test, was fired 40 rounds. The 'gun 
 was reported unserviceable. 
 
 A navy 13-inch Dahlgren gun, cast solid, at Providence, burst at the 
 172d round. 
 
 One or two other 13-inch guns, made for the navy, showed but low 
 endurance, but the committee have not been able to obtain particulars. 
 
 Wiard's 15-inch navy gun, of cast-iron, first of the class, burst at 
 Trenton, with a charge of 80 pounds of fine quick burning powder and a 
 solid shot of 886 pounds' weight. The gun was improperly cooled, by 
 which a lengthwise tension was inaugurated sufficient almost to break 
 the gun before firing. The muzzle broke off before the shot had reached 
 the point of fracture, as was shown by the shot having struck the frac- 
 tured surface as it passed. The second gun, cooled differently, was never 
 fired. The bureau annulled the contract (which provided for two or 
 more trials) before the second gun was tested. 
 
 The Whitworth 80-pounders, built up guns, mounted on Morris's 
 island, were disabled, each, at the lllth round, by the lengthening of the 
 inner tube, which protruded at the breech one inch in each case and shut 
 off the vent. One of these had a crack in the exterior coil of the reinforce. 
 
 Navy 11-inch gun, No. 1, exhibited cracks early during the proof, which 
 extended to a length of 24 inches at the 1,958th fire, and it burst at the 
 1,959th round into three great pieces, the fracture running through the 
 centre from the breech and branching off to either side forward of the 
 trunnions. 
 
 Two navy Dahlgren 80-pounder rifles were condemned as unservice- 
 able, and sold at auction for old iron. 
 
 Thirteen 50-pounder naval Dahlgren rifle guns, and 13 30-pounders of 
 the same kind, were condemned and sold. 
 
 Naval Dahlgren 30-pounder rifle, No. 54, cast solid at Washington 
 navy yard, burst at 34th round. 
 
 Navy Dahlgren 80-pounder rifle, cast solid at Fort Pitt foundry, burst 
 at the 377th fire ; was made of cold-blast charcoal, iron. 
 
 Navy Dahlgren 80-pounder rifle, cast solid at Fort Pitt foundry, burst 
 at the 852d fire. 
 
 Navy Dahlgren 50-pounder rifle, cast solid at Cornwall furnace, burst 
 at the 204th fire. 
 
 Naval Dahlgren 30-pounder rifle, No. 49, cast solid at navy yard, Wash 
 ington, burst at the 742d fire. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 217 
 
 Six navy Dahlgren 150-pounder rifle guns were sold at auction for old 
 iron. 
 
 Navy Dahlgren 7J-inch rifle-gun, 150-pounder, burst at the 27th round. 
 
 Navy Dahlgren 7-inch rifle, 150-pounder, fired 75 rounds, reported 
 unsatisfactory ; test not continued. 
 
 Navy Dahlgren 7^-inch rifle, 150-pounder, fired 60 times, reported 
 unsatisfactory ; test not continued. 
 
 SUMMARY OF BURST GUNS. 
 
 Parrott 100-pounders, (rifles) 60 
 
 Parrott 150-pounders, (8-inch rifles) ' 22 
 
 Parrott 10-inch rifles 1 
 
 Parrott 30-pounders 3 
 
 Hodman 12-inch rifles 4 
 
 Eodman 8-inch rifles 2 
 
 Eodman 15-inch smooth-bore, (navy) 17 
 
 Eodman 13-inch smooth-bore, (army) 1 
 
 Dahlgren 150-pounders, (rifles) 3 
 
 Dahlgren 80-pounders, (rifles) 2 
 
 Dahlgren 50-pounders, (rifles) 1 
 
 Dahlgren 30-pounders, (rifles) 2 
 
 Dahlgren 80-pounders, (condemned) 2 
 
 Dahlgren 50-pounders, (condemned) 13 
 
 Dahlgren 150-pounders, (condemned) 6 
 
 Dahlgren 13-inch smooth-bore 1 
 
 Dahlgren 11-inch smooth-bore 1 
 
 Miscellaneous wrought and cast-iron 9 
 
 150 
 
 Burst spontaneously 10 
 
 Cracked, fissured, or ruptured before proof 98 
 
 258 
 
 Eighteen Parrott 100-pounders, in addition to the above, are unac- 
 counted for, supposed to be burst. 
 
 Twenty-seven Parrott 150-pounders were condemned by the navy. 
 
 Of 43 Eodman 15-inch guns, cast for the navy, which was the great- 
 est number in service at any one time, 17 have burst or been disabled. 
 
 Of three 12-inch Eodman rifles, cast for the navy, one was rifled on 
 the plan of Mr. Parrott and burst at the 27th fire ; one on the plan of 
 Atwater, burst at the 30th fire : one on the plan of Eodman, burst at 
 the 16th fire. 
 
 Of four Dahlgren 150-pounder rifles one burst at the 27th fire, one 
 at the 20th fire, one at the 75th fire, and one at the 60th fire. 
 
 One 13-inch gun, cast solid, at Providence, endured 178 fires. 
 
 One 13-inch gun, cast hollow, at Pittsburg, endured 108 fires. 
 
 The navy 15-inch guns cast on Eodman's plan are divided by Admiral 
 Dahlgren into three classes : 
 
 1. The original Dahlgren model. 
 
 2. The same altered by Captain Wise. 
 
 3. The new model by Captain Wise. 
 
 Of the first class 34 were cast, 17 were altered to the second class. 
 Of these eight were disabled nearly Aa(/- after enduring but an average 
 of 135 fires for each. 
 
 Eep. No. 266 15 
 
218 EXPERIMENTS ,ON HEAVY ORDNANCE. 
 
 One-fifth of the unaltered guns were disabled after an average of 175 
 fires for each gun. 
 
 Sixty-six guns were cast of the third class. The trial gun endured 
 but 131 fires when it was disabled. 
 
 Of the remaining 65, 40 have only been fired the nine proof rounds ; 
 25 have been mounted in iron-clads and have been altogether fired 1,333 
 times ; one burst, three condemned, two of them sold as old iron. One- 
 fifth of these failed, being subjected to an average of 53 fires each. 
 
 NOTE. The guns above enumerated are all the 15-inch Rodman guns, . 
 which have been fired in service, none of the army guns having been so 
 fired. 
 
 The Eodmau gun was first officially adopted in 1862, by the ordnance 
 board of which the inventor and patentee was a member. When General 
 Dyer became Chief of Ordnance, in the fall of 1864, one of his first acts 
 was to appoint General Rodman constructor of ordnance. He raised 
 the price of the 15-inch gun to $7,000, which was previously $6,500, and 
 issued an order to receive the guns made under the supervision of the 
 constructor without subjecting tliem to the powder proof. Thus it can be 
 seen that General Rodman has held in succession tbree important posi- 
 tions in relation to the reception of his guns, one-twelfth of the whole 
 price of which he has received as royalty, viz : 
 
 1st. Inventor and patentee while an officer of the United States army, 
 and of the ordnance corps. 
 
 2d. A member of the ordnance board the power behind the throne 
 which adopted his invention officially for the service of the United States. 
 
 3d. Constructor of ordnance, charged with the inspection and recep- 
 tion of the guns in which he is interested as patentee, receiving a* 
 royalty. Two hundred and ninety-six 15-inch guns have been received 
 by the army ordnance department under this organization. Twelve 
 hundred and thirty-three 10-inch Rodman guns, and 155 8-inch, for which 
 carriages and a large supply of projectiles have been purchased. 
 
 There is no data upon which to found an opinion that the Rodman 
 gun, if subjected to service test, would have any special rate of endur- 
 .ance. None of them, except those referred to above as used in the navy, 
 have been fired in battle or service. A large proportion of them have 
 ibeen mounted, without having been fired at all. 
 
 The siege and sea-coast guns purchased by the army Ordnance Office 
 from the 1st July, 1861, to June 30, 1866, cost $5,354,365 57 ; of this 
 .amount $708,554 20 was paid for Parrott guns. The rest of this amount 
 was paid principally for Rodman guns ; $3,230,526 32 was paid for Par- 
 srott projectiles ; $289,105 80 was paid to Mr. Parrott for carriages for 
 Ms 100-pounders, 200-pounders, and 300-pounders. 
 
 The navy purchases from the Fort Pitt foundry, where the Rodman 
 .guns were principally made, amounted to $2,116,052 62. 
 
 The navy purchases from Mr. Parrott have not been ascertained. It 
 as believed that more than 175 100-pounder guns were obtained. The 
 number of the Dahlgren shell-guns which have been cracked or fissured 
 .inside previous to proof, or during experiments or service, could not be 
 learned. The chief of the bureau evaded the questions relating to the 
 i)ad qualities of his own invention, while he was elaborate in his answers 
 as to the bad qualities of the guns of other inventors. 
 
EXPERIMENTS ON HEAVY ORDNANCE. 219 
 
 EXPLANATION OF DIAGRAMS. 
 
 PLATE I illustrates the fractures usually occurring in guns, which are 
 of six descriptions, viz : 
 
 1. Eupture through the breech, along the reinforce, branching to either 
 side forward of, or at, the trunnions, as shown in Fig. 1. This fracture 
 is sometimes accompanied by cross fractures of the reinforce. 
 
 2. Eupture at the muzzle, as shown in Fig. 2. 
 
 3. Eupture caused by the blowing out of the breech, as shown in 
 Fig. 3. 
 
 4. Eupture in banded guns, by which a slab is blown off the side ot 
 'the gun forward of the band, as shown in Fig. 4. 
 
 5. Cracks on the exterior of the gun, as shown in Fig. 5. 
 
 6. Cracks in the interior of guns. (Not shown by diagram.) 
 
 PLATES II, III, and IV illustrate the general direction of fracture in 
 unbanded guns, cast hollow and solid, and of the old and new models. 
 Figs. 1 and 2, Plate II, represent interior and exterior lines of frac- 
 tures in a hollow-cast 10-inch Columbiad, old model. Fig. 1, Plate III, 
 shows the line of fracture in a hollow-cast of improved model, and Fig. 
 2 the line of fracture in a solid-cast gun of old model. Fig. 1, Plate 
 IV, represents the latest improved model of a Eodman hollow-cast gun. 
 Figure 2 represents a burst 13-inch gun of the same kind, showing the 
 general direction of fracture to be the same as in the preceding diagrams. 
 
 PLATES V and VI illustrate the cause of rupture, as shown by the 
 direction of fractures, supposed to result from the combined effect of 
 pressure and unequal heating. (See evidence of General Eodrnan, Gen- 
 eral Gilinore, and Norman Wiard. 
 
 PLATE VII illustrates the difference in the texture and strength of iron, 
 caused by difference in the rate of congelation when cast. 
 
 PLATES VIII and IX represent the Eodman external and internal 
 pressure metres. 
 
 PLATE X, fractures of guns at the breech. Fig. 1, Whitworth 
 80-pounder gun, with inner tube extended and protruding one inch at 
 the breech. Fig. 2, Parrott 200-pounder gun, with breech blown out. 
 Fig. 3, Armstrong 300-pounder, with breech blown out. Fig. 4, perspec- 
 tive view from the rear of same gun after the accident. 
 
 PLATE XI illustrates fissures and differences of texture in wrought 
 iron. Figs. 1, 2, 3, and 4 show fissures resulting from unequal cooling. 
 Fig. 5, crystallized wrought iron. Fig. 6, fibrous wrought iron. (See 
 evidence of Norman Wiard, and Appendix D.) 
 
 PLATE XII represents the Ames wrought-iron gun, and shows the 
 method of building up the gun by welding together a succession of cross 
 sections. 
 
 PLATES XIII and XIV illustrate the method of fabricature and mount- 
 ing of guns proposed by Norman Wiard, designed to provide for restrain- 
 ing the force of pressure and unequal expansion, and to cause the recoil 
 to be in the direction of the plane of the axis of the bore. 
 
 PLATE XV, experimental castings illustrating the effect of unequal 
 cooling on cast-iron. (See evidence of Norinan Wiard.) 
 
Plate I 
 
 Tlg.l 
 
 
 Fig. 3. 
 
 n 
 
 rig. 4. 
 
 Fig. 5. 
 
Plate II 
 
Plate III 
 
 Fig 2 
 
Plate IV 
 
 MEDIUM 13 INCH RODMAN CUN 
 
 flan 
 
 
 r i 
 
Plale V 
 
 Fig. 1 
 
 Fig 2 
 
 FigS 
 
 Fig 5 
 
 Fig 6 
 
 Fig 4 
 
 iff. 7. 
 
Plate YI 
 
 8 Inch. Columbiad. 
 
 Kgl 
 
 Fig 2 
 
PlatcTII 
 
 DIFFERENCES OF TEXTURE IN CAST IRON. 
 J)a& to differences in/ the rat&^of 'congelation; of the/ same irons, 
 whew cast w different sizes of mass. 
 
 BY NORMAN WIARD 
 
 r,g 2 
 
 Figl 
 
 Fig. 4 
 
 Fig 
 
 Fig. 1. cas-t 2 inches diameter, tensile strength '28,000 
 
 Fy. t. . 4 .. . " " 22,000 
 
 Fiq 3. 8 n . , MOOO 
 
 R 4 . 12 ,, , 16.000. 
 
Plate VIII. 
 
 17 3. 
 
Plate IX 
 
 RODMAN INTERNAL PRESSURE INSTRUMENT 
 
 .Section on A B. 
 
 Seclio/1 on C.D. 
 
 Fitf.3. 
 
Plate X 
 
 
Plate XI 
 
 .,;;.^- -,::-v 
 
 Fig 1 
 
 o 
 
 Fig3 
 
 > 
 
 Fitf. (> 
 
Plate XII 
 
Plate :xm. 
 
 Elevation 
 
 or 
 
 200 PS." WIARD RIFLE 
 Solid 
 
 Section/ on/ ss. 
 
 Section/ oiv tt. 
 
 DETAILS. 
 
 Combined JHfle and Smooth/ -tort*. 
 200 PB-* WIARD 
 
 wA. CaLSin, 
 
Plate XIV. 
 

Plate XV 
 

 
 
UNIVERSITY OF CALIFORNIA LIBRARY 
 
 THIS BOOK IS DUB ON THE LAST DATE 
 STAMPED BELOW 
 
 OCT 18 
 
 USE 
 
 DEC 281960 
 
 LD 
 
 REC'D LD 
 
 JUL 31963 
 
YC 6429! 
 
 UNIVERSITY OF CALIFORNIA LIBRARY