“100 Pounder Parrott Bursting aboard United States Steamer Juanita. December 24th, 1864 - Harper’s Weekly - January 21st, 1865.

100-Pounder Parrott Shell and “Cannon Tube Fragment” recovered from Fort Fisher (looks like a piece from near the muzzle of a pre-war 24 or 32 pounder to me) displayed at the new visitors center and museum of **Fort Fisher State Historic Site**. The text which accompanies the shell says “The US Navy outfitted warships with many 100-pounder Parrott guns to bombard Fort Fisher. Prone to catastrophic failure, no less than five of these cannons exploded upon firing during the first battle, killing and wounding gun crew sailors.” Note the grooves cut by the rifling into the brass base of the 100-Pounder shell.

The interpretive sign from Fort Fisher states that Parrott Rifles were “prone to catastrophic failure.” Indeed at the First Battle of Fort Fisher, five 100-Pounder US Navy Parrott Rifles burst, resulting in 45 casualties in the the bombarding fleet - more casualties than caused by Confederate fire. (Figure of 45 casualties cited both in Gragg’s Confederate Goliath and Mike Ryan’s “Historic Guns of Forts Sumter and Moultrie”.)

How dangerous were Parrott Rifles to their own crews? According to Ryan’s research, out of the 233 100-Pounder Parrott Rifles produced for the US Army, 30 failed - 29 of those while firing on Morris Island. Out of 352 100-Parrott Rifles produced for the US Navy 29 failed in incidents from 1862 to 1865. Out of 91 200-Pounder (8-Inch) Parrott Rifles produced for the US Army, 10 failed - all on Morris Island. Out of 87 150-Pounder (8-Inch) Parrott Rifles produced for the US Navy, 8 failed in individual incidents. While some of the failures were catastrophic, casualty causing bursts at the breech as depicted in the Harper’s Weekly illustration, others were cracks or burst near the muzzle with few or no casualties.

Ryan also lists one 10-Inch Parrott bursting at the muzzle on Morris Island and three US Army 30-Pounder Parrotts bursting on Morris Island. Those 30-Pounders burst at the 401st, 2900th, and 4,606th rounds. The US Navy report below also lists only 3 30-Pounders failing in Navy service. Two of the US Navy 30-Pounder Parrott failures occurred while using “compressed powder” as propellant while the third 30-Pounder which failed had previously been “stuck on the band by a shot or shell.”

Some of the larger Parrotts were capable of long service, too, with many firing hundreds of rounds - the records seeming to be 1,457 rounds for an 8-Inch and 1,590 rounds for a 6.4-Inch (at least among those that eventually failed). On the other hand a few US Army Parrott Rifles failed extremely early - one 100-Pounder on its 6th round and famously the 8-Inch “Swamp Angel” failed on its 36th fire. (Summary of table found in “The Historic Guns of Forts Sumter and Moultrie” by Mike Ryan, 1997. pp. 61-62. Total Parrott production figures from The Big Guns.)

After the five failures in the December 24th bombardment of Fort Fisher, the US Navy Bureau of Ordnance sought to determine the cause of the failures and examine remedies. The preliminary report along with information supplied by Robert Parker Parrott was printed in The United States Army and Navy Journal and Gazette of the Regular and Volunteer Forces in February 4th, 1865. The original article is linked here. (https://babel.hathitrust.org/cgi/pt?id=coo.31924069759862&seq=380) I have created the following transcript of the report and Mr. Parrott’s remarks. Any mistakes in the transcript are mine.

REPORT ON RIFLED GUNS

----

Letter of Instructions.

Bureau of Ordnance

Navy Department

Washington City, 4th January, 1865.

Sirs, You are hereby appointed a Board to consider and report upon the subject of Rifle Cannon for the Navy.

In consequence of the unfortunate failure of a number of the Parrott guns in recent operations near Wilmington - the report of which will be submitted to you - and the loss of life attendant thereon, the confidence of the service has been seriously shaken in the guns of this manufacture; and some change or modification of the system is thus rendered necessary.

You will, therefore, investigate, as fully as possible, the causes of the failure of the Parrot guns in the service generally, and state whether, in your judgement, they are still worthy of confidence, and should be continued as the Rifle Guns of the Navy; or whether they shall be abandoned and some other gun substituted.

If you should decide upon retaining the Parrott system, you will state whether the present calibres shall still be used; and if not, what calibres shall be rejected; also whether it be advisable to reduce the charge and weight of projectiles for the several classes of the guns you may propose.

If, however, you decide to abandon the Parrott system entirely you will designate either a new rifled gun or a new mode of manufacturing rifled guns, which in your opinion will be the safest and best for the Naval Service, keeping in view the question of economy in manufacture relatively with the results anticipated from the change.

Having thus decided upon a rifled gun, or a mode of manufacturing them, you will state in what proportion they shall be placed in the batteries of our ships.

A full record of your proceedings must be kept, and a detailed report made to this Bureau of the results of your deliberations; to aid you in which the files of this office are placed at your disposal.

I am, Sirs, your obedient servant,

H.A. Wise,

Chief of the Bureau

Commodore J.Z. Missroon, U.S. Navy

Commodore R.B. Hitchcock, U.S. Navy

Commodore T.A. Hunt, U.S. Navy

Lieutenant-Commander R. Aulick, U.S. Navy

Lieutenant-Commander W.N. Jeffers, U.S. Navy

————————————————-

The Report

Navy Department

Washington, January 18. 1856

Commodore H.A. Wise,

Chief of Bureau of Ordnance

Sir: - In accordance with your order of the 4th instant, we have carefully considered the points therein submitted for investigation, and have the honor to report as follows.

We find that (703) seven hundred and three Parrott guns of all calibres have been issued to the Naval service, (As shown in Table A), and that of this number (21) twenty-one have burst of been otherwise injured by explosion.

Table of Parrott Rifles which burst in US Navy Service

Several of the injuries have appeared in fractures or rents, enabling the withdrawal of the guns from service in time to avoid casualties, and many of them have occurred in the chase or at the muzzle, and not, as is customary with other guns, at the breech; thus affording evidence that they arose from the premature explosion of the shells within the guns - a fact which is proven by the direct testimony of several officers in charge at the time.

Such premature explosions of shells within rifle guns have frequently occurred without apparently injuring the guns, while in other cases causing their instant rupture. But although the guns were apparently not injured, there is no proof that they were not really so, and much presumptive evidence that they were; for, although we find by the records that many premature explosions of shells have been reported to the Bureau at different times, by which the gun was not apparently injured, yet on no occasion has it seemed to occur to the officer so reporting that an examination of the gun itself was necessary to determine what effect had been produced by such premature explosions.

Thirty-three (33) premature explosions in (112) one hundred and twelve rounds have been reported in target practice with guns of all calibres, and not one word said of any examination of the guns.

There is, however, one instance that occurred, in the proof of a 100-pounder at Cold Spring, which is conclusive on this point.

At the second fire of this gun a shell exploded prematurely, and the gun showed no apparent injury, and stood the ten proof rounds without bursting; but a subsequent examination showed it to be seriously cracked at the bore, and it was rejected.

Brigadier-General Turner, Chief of Artillery in the Department of the South, during the operations against Charleston, states (see General Gillmore's Report, p. 155) that

"a most serious matter was the premature explosions of shells, of which so many have occurred in our firing. The shock produced by an explosion of a shell within a gun cannot but tend rapidly to destroy it; indeed, in instances which have come under my personal observation, I am confident it was the direct and immediate cause. In one instance of the bursting of a 100-pounder where the breech had ben blown from the reinforce, I found the base of the shell in the gun. The shell had prematurely exploded, leaving the base in the gun; it had taken the grooves and was left perpendicular to the axis of the piece, and some inches in the rear of its first position, showing that the last force acting upon it was from the explosion of the powder in the shell."

The same report says, page 139, that "the frequent instance of premature explosions which occurred with shells (from the Whitworth guns) made it necessary to abandon the use of shells entirely."

The records show that in this subject of the frequent premature explosions of shells in the rifled guns has been fully appreciated by the Bureau, and that experiments for the purpose of obviating it, by coating the interior surface of the shells, have been made for more than a year past.

These experiments show that as the coating became more and more perfect, the premature explosions of the shells decreased, until they ceased entirely.

Seven hundred (700) rounds having been fired without a single instance of such explosion of the shells, or injury to the guns.

The result has only been obtained within the last few weeks, and consequently is not known to the service generally; nor were the shell which have heretofore been issued for service coated inside, because until now no substance was found for coating them which seemed to fill all the required conditions, though some few have been partially protected.

As these experiments may not, however, be considered sufficiently extended to be conclusive, and as the premature explosion of shells is shown to be certainly one cause of the failure of the Parrott guns, and is, in the opinion of the inventor, the principal one, we think that this subject should be so fully tested as to place the question of this cause of bursting of those guns beyond dispute; and also whether it be possible to obviate it entirely or not.

We, therefore recommend, that a series of experiments be at once instituted at Cold Spring (or such other point as the Bureau may designate), to be conducted in the following manner:

Three guns - say 100-pounders of exactly the same character in every respect, that is, made from the same iron, melted at the same time and in the same manner, and cast all at once from the same pool - should be placed side by side and fired 1,000 rounds each with service chares of powder and shells of the same description and weight, the shells from one gun to be unleaded (but brought up to weight by filling them with sand or some other non-explosive material), then those from the second gun to be loaded and fused, but not coated on the interior; and those from the third gun to be coated on the interior with the new composition, and leaded and fused exactly as those from No. 2. In every other respect the conditions of the firing should be exactly the same, including for a certain number of rounds rapidity of firing.

It is believed that these experiments will fully test both guns and projectiles under all the circumstances that are like to occur.

We are of the opinion that from the result of these experiments it should be decided whether the Parrott guns are to be retained or withdrawn from service; for, after a minute and careful investigation of all the information we have been able to obtain, as well as from the records of the Bureau, the testimony of Mr. Parrott (see paper marked D), and our own personal experience, we find it impossible to decide at present.

Pending this decision, we consider it proper to recommend to the Bureau (see letter Jan. 11th, marked E) that a general circular should be issued, directing certain reductions of the charge of 100-pounders, and other precautionary measures to be taken, by which it is hoped that serious accidents may hereafter obviated.

That these guns have in some instances been injured by other causes than the premature explosions of shells, such as the use of compressed powder, projectiles deemed by Mr. Parrott unsuitable for guns of his construction, by keeping guns loaded for a great length of time, and also by neglect in the heat of battle to lubricate the projectiles as required by the Ordnance instructions - a most necessary and important precaution, having for its object not only the free movement of the projectile, but particularly as a means of neutralizing the tenacious deposit from the powder, which is admitted in some cases to have been done; there seems little doubt but they are exceptional cases.

The compressed powder used at one time in the Parrott guns was authorized by the Bureau on the recommendation of Mr. Parrott and the ordnance officer stationed at his foundry; but, having proved injurious, its use has been discontinued.

That premature explosion of shells will burst rifle guns of wrought-iron as well as those of cast-iron, is shown by an instance stated in the English Army and Navy Gazette of December 24, 1864, to have recently occurred in England in the trial of an Armstrong gun.

Table B, appended hereto, shows the extreme endurance of Parrott guns in proof and in service, as far as we have been able to obtain it. The reports of service are, however, by no means full, and some reports date more than a year back. It may be assumed, therefore, that many guns stood more firing than is shown by the table.

Table of Extreme Endurance of Parrott Rifles IN USN Service

Table C shows the number, manner and cause of failure, of these guns in service, as far as reported. In this case also it should be remarked that the reports are very incomplete, and in some instances give no date on which to found an opinion as to the cause of failure.

Records of Individual Burst Parrott Rifles and Suspected Cause

In consideration of the endurance exhibited by the Parrott rifle guns in proof and in service, we deem it proper to state that, in our opinion, the Bureau was fully justified in adopting them for the Naval service, as the best guns to be obtained to meet its immediate wants - various other systems of cast-iron ordnance having either failed or been withdrawn from service as unreliable.

We, therefore, in the belief that the guns of this description which have burst or failed, may have been affected by one or more of the causes heretofore enumerated, especially the explosion of shells within them at the time of bursting, or previously, recommend the retention of all classes of those guns, except the 150-pounders, until the experiments herein recommended shall have been made.

We would also suggest the immediate withdrawal of such of the Parrott guns as may have been subjected to any of the deteriorating causes indicated above; and that they be issued to vessels of the Navy only as chase guns, not to exceed two for large and one for small vessels, exclusive of rifled howitzers.

With respect to wrought-iron cannon, all the official information to which we have access, show that the results in large calibres have not been favorable to their endurance, and in many cases they have shown less strength than case iron guns. Instance the original gun of the Princeton, the "Oregon," which cracked, and the second gun, the "Peacemaker," which burst explosively, causing great damage.

The 13-inch gun, made within the past year by Mr. Ericsson, has been able to sustain by a very limited number of rounds.

An 80-Pounder, constructed in the Washington Navy Yard, also a gun of the same caliber made by Messrs. Seyfert, McManus & Co., at Reading, showed decided flaws before proof.

Several wrought iron cannon of the manufacture of Mr. Horatio Ames, have been subjected to trail; one, of the caliber of a 50-pounder, enduring 1,600 rounds; and, although showing deep fissures at the bottom of the bore, yet might still endure an indefinite number of rounds, the experiments having been suspended on account of excessive enlargement of the vent.

A cast-iron 50-pounder of the same model endured 2,000 rounds. These calibres have sufficient endurance in cast-iron or the banded guns of Mr. Parrott.

The semi-steel guns of Mr. Norman Wiard, of the calibre of 50-pounders, were experimented upon; but the very limited and unequal endurance of these guns - one bursting after nine rounds - caused the abandonment of experiments in this direction.

Nor have the published official and semi-official accounts of the endurance of foreign rifled ordnance of heavy calibres, always been so satisfactory as to lead us to recommend the entire adoption of the wrought-iron, or any other system to the exclusion of the banded cast-iron. The Armstrong 10-inch 5, and other heavy calibers of various makers, have endured by a limited number of rounds and then the former burst explosively by blowing out the breech.

A Whitworth 70-pounder rifle gun, now at the ordnance yard, has commenced to unscrew at the breech, and the trunnion band is badly cracked, after 32 rounds. Two others captured in a blockade-runner and placed in battery on Morris Island, were disable after a hundred and ten fires. Even the 110-pounder Armstrong does not appear to be exempt from serious defects as a Naval gun, as the rupture of a shell in the bore of one, appears to be capable of destroying the gun (vide Army and Navy Gazette, December 24, 1864).

The Ames gun, lately submitted to proof before a joint commission of the Army and Navy - a member of this Board being also a member of that commission - has show great strength and endurance, although fissures were developed at an early stage of firing; but in its present shape it is of too small a calibre and unsuitable form and weight for any service in any class of vessels in the Navy. But as the inventor does not claim any peculiarity of form, but only in the mode of manufacture, and asserts his ability to make guns in any form, we recommend that a gun be designated by the Bureau, of suitable calibre, form and weight, for the turreted vessels, and submitted to proof, and that the 150-pounders in those vessels be immediately withdrawn, as the effect of an explosion in vessels of that class could not fail to be most disastrous.

Until the opinions herein expressed have been verified by the experiments which we recommend, we do not feel prepared to make a final decision upon the questions submitted to us; and we therefore respectfully suggest that further consideration of them be, for the present, suspended.

We are, sir, very respectfully your obt. servants.

J.Z. Missroon, Commodore, U.S.N

R.B. Hitchcock, " "

T.A. Hunt, " "

R. Aulick, Lieut.-Commander U.S.N.

W.N. Jeffers, " "

Item D: Questions Asked Mr. R. P. Parrott, with his Answers Thereto.

Q 1. How do you know in handling your guns that the band may not be shrunk on too tight - or, in other words, that the shrinkage may not be so great as to compress the cast-iron beneath it, thus changing its structure by upsetting or displacing the crystals, and consequently diminishing or destroying its strength?

A. In my opinion it is not sufficient to do so. Every gun is turned, and band bored to the same gauge, that is, the difference between the diameter of the band and gun, cold, before band is put on, is always equal to one sixteenth of an inch to the foot.

Q 2. Has it not actually occurred in practice at the foundry that the band has been shrunk on too tight?

A. No. In the first 30 pounder, in putting on the band the bore was found to be reduced about 0 inch .01. A similar result was also found with a 100-pounder gun. On this account I prefer to do the finishing out and rifling of the bore after banding the gun. I have, however, finished bores entirely before banding, as was the case with all the old army guns banded for experimental purposes.

Q 3. If it should occur, will it not in your opinion be sufficient to account for the blowing out of the breech of so many of your guns?

A. If too much compressed it might damage the gun; but I do not think that a band of the thickness we use could be put on with sufficient force to do so. I think that if any excess in shrinkage exists the band would adjust itself. It is always put on at a uniform heat - what is called "red-in-the-dark."

I do not think that in any case the band have been put on so as to weaken the guns. The band is intended to guard against longitudinal splitting, which is the manner in which guns usually fail; and of course if this is prevented the gun fails in the next weakest place.

We banded a lot of old army guns, and all the banded guns stood well, whilst several of the unbanded ones failed.

Q 4. Have you any experimental results relative to the amount or difference of shrinkage in similar bands? Have you any means of securing uniformity?

A. I have no experimental results to determine shrinkage beyond daily practice in making guns. They are all prepared with a uniform difference of one-sixteenth of an inch to the foot. This difference is absorbed partly by the extension of the band and partly by compression of the cast-iron. The band would be of no use if its effect was not felt at the bore.

Q 5. Would any modification of the form of the band, or method of putting it on, make it more uniform in its action or give it greater strength?

A. I do not think it would be well to change the form of the band. Of course a longer and heavier band would be stronger; but I do not think the difficulties lie in that direction. I should be unwilling to depend on the band for giving longitudinal strength. it has not much strength in that direction. Bands shrink more in the centre than at the ends, and consequently there can be "nip" at those places.

I do not think that there would be any difficulty in lengthening the forward part of the band a little; but I think it would do little or no good in obviating the accidents in that part which are caused by the explosion of shells.

I think it would be a confession ok weakness in that direction, which does not exist.

Q 6. Have you ever tried to band over one of your guns cold - that is, by simple pressure, hydrostatic, or otherwise?

A. I have never tried banding cold, because I do not think it so good and certain as banding hot. It is fully practicable, but the abrasion of iron if the band were forced on with the same tension as I obtain by putting it on hot would deprive it of the expected accuracy.

Q 7. What is your opinion of the premature explosion of shells and its effect on the gun?

A. In the rifle cannon there are many new elements and things to learn which have not yet been solved by direct experiment.

I think that the premature explosion of shells is the great cause, if not almost the only cause, of the bursting of these guns.

Sand or dirt would wedge the shell in the gun, the windage being so small, which I have no doubt caused a few guns to burst at Morris Island.

Q. 8. What security have you that the shells are not frequently crashed in the gun by shock of the discharge independently of any premature explosion of the powder in the shells? Have no unloaded shell ever been broken in the guns?

A. I have no evidence that the shells want strength, after the experience of many thousand fires, to stand the direct shock of the discharge. No unloaded shells, so far as I recollect, have ever broken in the guns. A great many unfilled shells have been fired and none broken in the gun. One hollow shot that did break; but in these projectiles the cavity is in the rear end, and the base not quite so strong as that of the shells.

Bands of shells sometimes fly off or break, but I do not think that this endangers the gun.

In think that imperfect fuses may have sometimes caused accidents, but I have no knowledge that the spelter rings have ever failed; though as first made, they might have been a source of accident by flame getting down alongside the thread of fuse hole into the shell.

I have never known, after hundreds of fires, a fuse of any kind to be driven into the shell.

Q. 9. What advantage do you expect to derive by an increasing twist in the rifling over the regular or uniform twist? Is there any danger of wrenching off the muzzle by the "nip" the projectile receives at that point?

A. The principal advantages to be gained by the increasing twist are that the projectile takes the grooves more readily, that a higher rotation may be more easily obtained, and a stronger band used with the projectile. Bands of hard metal take the grooves fairly, which they would not do so well with a regular twist. If the groove is straight the band enters it directly, but if curved it has a tendency to ride over the grove before complete expansion

No gun has ever broken at the muzzle except by the premature explosion of the shell, within my knowledge.

Q. 10. Could the weight of the projectile and the charge of powder for the 100 pounder be reduced, say to eighty pounds for the former and eight pounds for the latter without materially diminishing the efficiency of the guns, and would not such reductions increase materially the endurance of the guns?

A. The "short shell" is a good projectile, and its use would not materially diminish the efficiency of the gun, while the endurance would certainly be increased by such reductions.

The heavy shell and ten pound charge give greater power, of course, and in cases where very long range and great shell-power are required it may be necessary to use them, and they were designed for such purpose.

Q. 11. Are Parrott rifle shells cast with a hole in the base for the purpose of more readily cleaning them? If so, by what means is the hole plugged or closed?

A. The Parrott shells, above 60-pounders, are now cast with a hole in the base for steadying and centering the core in the flask. This hole affords facility for cleaning them, and is filled by a rivet having a head which effectually prevents them being driven into the shell. No instance of it having been driven in, in many hundred recovered after having been fired.

Q. 12. May not premature explosions be cause by the crushing of shells in the bores of rifled guns, when the shells are porous?

A. I do not believe that premature explosions occur by the crushing of my shells within the bores. By the mode of casting them with the base downwards, the liability to have porous metal at the base is removed. There is a solitary instance known to be of crushing a projectile within a gun (a hollow shot) in many thousands that have been fired.

Q. 13. May not the imperfect adjustment of the fuse, the weakness of the spelter rings or the imperfect manufacture of the time-fuse, be another cause of premature explosion?

A. I think that the original spelter ring (cast) did admit the probability of the gas entering the shell and exploding it, but those now made by being cut, and having a "shoulder" removes that probability.

Imperfect fuses or imperfect adjustments of fuses would of course be liable to admit gases into a shell, but not more so in the Parrott than in any other shell.

I would respectfully submit to the Board the following remarks as due to the importance of the subject and to my own position.

R.P. Parrott.

Washington, January 16, 1865.

________________

I am unable to find in revising my correspondence that I have failed to express on all proper occasions my opinion that most of the accidents to my guns have resulted from premature explosions of loaded shells taking place within the bore, although I believe that the sand blown, or otherwise accidentally carried into the guns, was an operating cause of bursting at some of the positions on Morris Island.

But I do find that I have failed to give as decided an expression to my views as the importance of the subject required. The partial success of the trials made experimentally at this place to prevent premature explosions of shells, and the prospect that means entirely efficacious would soon be found, have induced me to look upon the difficulty as one which would shortly be remedied; and, indeed, I can say that it has been by the precautions now taken in firing loaded shells, which consist in lining the interior with a substance effectually covering the rough surface of the iron.

The great danger connected with these premature explosions, is the injury which the gun my suffer from a single one, not probably fatal at the instant, but leaving the gun impaired and causing its destruction under the subsequent firing. Thus doubt and distrust are thrown upon the character of the guns, which burst without any cause assignable at the time of failure. I do not suppose that one or many shells could not explode in the bore of rifled cannon without serious danger to the gun, but have no doubt that it might be destroyed by a single explosion of a shell; and fear that irreparable damage would be caused by some one out of not a very large number of such accidental explosions.

I must say that the apprehensions I have expressed on this subject have been received with not a little doubt, and that I found most persons skeptical in regard to the causes of the explosion of shells in the bores of rifle cannon, and some as to the danger of such explosions from whatever cause.

In referring the premature explosions of rifle shells to the friction or attrition to the powder contained in them, I do not of course deny that such explosions may sometimes be the result of defects of the shells, or of the fuses; but I do not say that with ordinary care taken in respect to the inspection and other points, few if any of my shells will explode prematurely, except by the friction of the powder within, and that if the interior surface of the shell is effectually covered these explosions will cease.

What I state has been derived from actual trial, and is substantiated by facts officially noted in the proof and inspections of rifle guns.

It has often been asked why should the rifle shell explode prematurely more frequently than the spherical? It may be answered if the rifle shell is charged with only the same quantity of powder as suffices to fill the spherical of the same caliber, explosions will rarely if ever take place. But as the rifle shells hold from three to four times as much powder as the spherical, the greater weight of the powder, and that in a long column, must by its reaction on the firing of the gun press with much greater force, and by friction either on the bottom or along the sides of the cavity of the shell (if left rough as cast) cause an explosion.

Such being the facts in respect to the explosions of rifle shells and the means of preventing them, are they the cause of the unequal endurance and unlooked for bursting of the guns?

I am unable to trace any connection between the bursting of the guns and the time of manufacture. The difficulties of procuring supplies of material and of labor, have been unexampled within my experience, but I am not aware of any deterioration in the work, and feel confident that there has been none which can possibly account for the failure of guns, though the supposed necessity for assigning some cause such as would be applicable to ordinary cannon has led to the supposition that a gun which fails must have been bad from the beginning.

It would be as unjust to expect of me to foresee all the difficulties which may arise in the use of a system of ordnance so new as that of rifle cannon, as it would be presumptuous on my part to pretend to do it. I cannot think, however, that the merits which mine have exhibited are merely accidental, but believe that from the uniformity of plan and the results, with the extreme sizes that no intermediate class can be wrong in principle. I know of no possible cause other than the explosion of the shells which would account for the busting of my guns near the muzzle. it has been known to happen the very first round fired from the gun, after a very few, after some hundreds, and in the two 10-Inch guns, destroyed in this way, one after twenty-seven and the other after one thousand and four fires in actual service. In a very few instances it has happened with the 30-pounder guns after quite moderate use, and in one it did not take place up to four thousand six hundred and fifteen fires.

Again as to those peculiar modes of bursting by which portions of the cast-iron are blown off forward of the wrought-iron reinforce or near the trunnions, often leaving al the rest of the gun still connected together, how can it be supposed that these accidents occurring after very irregular periods of service can be the results of any uniform and natural action of the charge? The explosion of so much additional powder as the shells contain, though undoubtedly adding materially to the strain upon the gun might not seriously damage it; but as the base of the shell will probably be in one piece with the ring connected, and the sides of the projectile driven laterally against the bore, it is not surprising that partial jamming of these should take place and try the gun to a dangerous point.

I have portions of the front or curved end of a shell bust in the gun, which are so marked as to show these fragments to have been violently forced into the grooves. Although I conceive that the failure of the guns at any part forward of the reinforce is certainly due to accidents occurring with the projectile, I cannot conclude that similar accidents might not cause the bursting of the gun in another part depending on the position of the shell at that time. In one instance at Morris Island, the base of the shell was actually found in the gun after the blowing off the breech.

In other case the cast-iron may be so injured by previous explosions as in bursting to carry the band with it.

In conclusion I would express my believe that I have correctly assigned the causes of the bursting of my heavy guns. I do not consider that they are less safe than ordinary cannon when subjected to the same regularity of strain.

On account of the very uncertain action of shells prematurely exploded in the bores of rifle guns, we are unable to determine the extent of injury, therefore, and cannot judge the number of rounds which the guns can subsequently be expected to endure with safety.

At the same time I am satisfied that the means now used do effectually prevent the premature explosion of the shells and thus remove the greatest cause of danger to the guns. It is due to the subject and to myself that I should advert to the firing of other projectiles than my own in my heavy guns. I cannot but think that many shells much inferior to those which the same makers would now supply, have been used in my rifle guns, as well as many projectiles of an experimental kind.

The action of powder in the rifle takes place under circumstances very different from those existing with the spherical projectile, and in my judgment far too little consideration has been heretofore given to this point as connected with the durability of the guns.

R.P. Parrott.