TJ 301 .C5 B6 Copy 1 T BOILER EXPLOSION OF THE MARTIN BOILER ON BOARD THE U S. " DOCBLE-ENDER CHENANGO. The Coroner's Inquest, A FULL REPORT OF THE TESTIMONY, THE CHARGE OF DR. NORRIS TO THE JURY, AND THE TWO VERDICTS PUBLISHED BY HURD & HOUGHTON, 401 BROADWAY, CORNER WALKER STREET. . 1804. .<*HSTl- THE BOILER EXPLOSION OF THE MARTIN BOILER ON BOARD THE U. S. " DOUBLE-ENDER CHENANGO. The Coroner's Inquest, A FULL REPORT OF THE TESTIMONY, THE CHARGE OF DR. NORRIS TO THE JURY, AND THE TWO VERDICTS JOHN A. GRAY & GREEN, PRINTERS AND STEREOTYPERS, FIRE-PROOF BUILDINGS, CORNER OP FRANKFORT AND JACOB STREETS. 1864. -T3?>o\ h* Y.M 60818 THE CHENANGO DISASTER. On the morning of the sixteenth day of April, 1864, Thomas P. Norris, Coroner of Kings County, was summoned to investigate the cause of the death of a number of men then lying dead at the U. S. Naval Hospital in Brooklyn. These men were transferred to the hospital from the United States double-ender gunboat Chenango, one of whose boilers exploded the day previous while on her first passage to sea. The Coroner, as soon as practicable, summoned the following gentlemen to officiate as jurors, namely : ABM. INSLEE, Foreman. Wm. H. Bigelow, Theodore Ovington, Robert G. Anderson, William Arthur, Norman Hubbard, Thomas Kelly, R. J. Hutchinson, Lancelot Keskup. The jury, with the Coroner, visited the hospital, where they were em- panneled, and fixed upon the nineteenth day of April to commence their sessions. On the eighteenth the Coroner wrote the following letter to the Hon. Gideon Welles, Secretary of the Navy : Coroner's Office, Brooklyn, April 18th, 1864. Dear Sir :*The judicial investigation into the circumstances of the late ex- plosion on board the United States ship Chenango will be commenced to-mor- row p.m., before me and a jury; and as the magnitude of the disaster calls for a very thorough sifting of the whole affair, I have to ask you to request the following gentlemen to report to my court for the purpose of testifying in the case, and to remain during the investigation : Benj. F. Isherwood, Engineer-in-Chief ; S. Wilkins Cragg, U. S. ship Shamrock ; George Sewell, Engineer, Boston Navy -Yard ; W. W. Wood, Engineer Inspector U.S.N. ; and Mr. Cunningham, 1st Assistant-Engineer, who, I understand, is now in New- York on special duty. Very respectfully, Thomas P. Norris, Coroner of Kings County. To Hon. Gideon Welles, Secretary U. S. Navy. P. S. — I shall be happy to hear any suggestions which the Department may desire to offer during the inquiry. T. P. N. To this the following reply was received by the Coroner. It is dated on the twenty-first, but was not received till the twenty -fifth : Navy Department, "Washington, April 21, 1864. Sir: I have received your letter of the 18th inst. The officers, whose testimony may be desired in the case of the disaster to the Chenango, can be summoned to appear before the Coroner's Court, and they will be required to comply with the summons. Very respectfully, etc., (Signed) Gideon "Welles, Secretary of the Navy. To Thomas P. Norris, Esq., Coroner, Brooklyn, N. Y. Immediately on receiving this letter, Coroner Norris inclosed a copy of it with a subpoena to Mr. Isherwood, to which he received the following tele- gram: Washington, April 25th, 1864. To T. P. Norris, Coroner, Governor's Room, City Hall : Subpoena just received. Public business will be inconvenienced if I leave here before Wednesday morning. Will that time answer ? Please reply by telegram. (Signed) B. F. Isherwood. To this the Coroner replied by telegram that Thursday afternoon or even- ing would do. On receipt of this Mr. Isherwood replied as follows : Washington, April 26th, 1864. To Thomas P. Norris, Coroner : I will be at the City Hall Thursday afternoon. (Signed) B. F. Isherwood. Thursday afternoon came, but Mr. Isherwood did not come. He was in New- York, however, all that day, as the following letter will sbfcw : Navy Department,* Bureau of Steam Engineering, April 29th, 1864. Dear Sir : I had arrived in New-York, and would have attended your inquest, but was ordered suddenly back to Washington. I barely had time to ask Mr. Everett to make this explanation to you. Your obedient servant, Coroner Norris, Brooklyn, N. Y. B. F. Isherwood. Mr. Isherwood arrived in New- York in the morning, and did not leave for Washington till the evening, as the Coroner was informed by Mr. Everett. Why he refused to visit the court during that day is not explained by his letter, especially after traveling so far for the purpose of testifying. It is not easy to understand what business Mr. Isherwood could have had to attend to more important than that for which he was ordered to the Coroner's Court. TESTIMONY. The Jury assembled at the Governor's Room, at the City Hall, Brooklyn, on the nineteenth day of April, 1864, at three o'clock in the afternoon, when Coroner Norris addressed them as follows : Gentlemen : You are about to enter upon an investigation into the circumstances of the recent calamity which occurred upon the United States vessel Chenango. The magnitude of the results of this disaster has appalled the whole country. The nature of the questions to be asked and answered in an investigation of this kind involves the necessity of placing on the Jury men of well-known ability in the sciences to which these questions refer. It was in view of this fact that I have selected you, gentlemen, to assist me. I feel confident that you fully appreciate the importance of exercising patience, and of divesting your minds of any preconceived opinions which you may have formed in regard to the various scientific ques- tions bearing upon this case, so that you may decide upon the facts as will be given in testimony alone. With these few remarks, gentlemen, we will now proceed. James F. Sullivan, sworn, says : My name is James F. Sulli- van. I reside in Kent avenue, between Myrtle and Park avenue. I am a machinist. I am employed in the IT. S. Navy, on board of the gunboat Chenango. I am acting Third As- sistant Engineer. I served my time in Mr. James Bing's shop, and passed an examination in Philadelphia before I got my appointment. I was on board the Chenango on the 14th in- stant, at the time of the explosion. I was in the pilot-house at the time of the explosion. I was not in the engine-room from the time we left the Navy Yard until the explosion took place. The explosion I think occurred about a quarter past four o'clock p.m. I went below as soon as I heard the ex- plosion, and on my way down I met Mr. Cahill, the Chief En- gineer, at the head of the stairs on deck. He asked me to get him a drink of water. I then went below and stopped the en- gine. I had not observed any thing unusual about the working of the engine ; every thing was working easily. After stopping the engine I tried the cocks on both boilers, and found no water in either toiler. I also looked at the steam-gauges, and found that they had been turned back to nothing. Mr. Cahill, before death, said that he thanked Grod that he had two and a half gauges of water in the boiler. When I shut the in- jection-valve and the outboard-delivery, I returned to the fire- room, and ordered one of the Master's mates to take a lantern and see where the water that was coming through the deck was coming from. I had the ash-pit doors closed and the connection and furnace doors open, and started to draw the fires. When the ship first went in commission on the 29th day of March, 1864, or February, the weather was quite cold, and we got up steam on the port-boiler to heat the wardroom and Captain's cabin. We kept steam on the boiler for about a week ; during that time the boiler leaked so badly that we marked all the places where it leaked with chalk. There was two tubes that leaked. We then got up steam on the other boiler. The following day Mr. Cahill sent me to the Morgan Iron Works, to let them know the state the boiler was in, and requested them to send a man over to repair it. They did not send a man over for several days; we had to put our own men on to repair it, before the men from the Morgan Works arrived. We had repaired the leaks in the port-boiler before the men arrived, and set the men from the Morgan Works on the starboard-boiler. We then went and examined the other boiler, and found that it leaked still, and directed the men to go to work on it. They went to work on it, and cut two tubes out, and put in two new ones. They also caulked it wherever we had marked it. We then started our donkey- pump to put a water-pressure on it, and could get but twenty pounds. I do not know why, except the boiler leaked. We could not get the pressure on the boiler ; on the starboard- boiler we got from forty to forty-five pounds of water-pressure. I recollect hearing the engineer, Mr. Cahill, say, that he had a good engine, but a pair of kettles, meaning the boilers. Mr. Murray, the senior Second Assistant Engineer, always said he was afraid of the boilers. He gave no reason, only that we were always tinkering at them. None of the engineers had a chance to see the boilers while they were building. I am the oldest engineer attached to the ship. Mr. Cahill did not make the remark about the water in the boiler to me, but to the Sur- geon of the ship. I was not present during the trial of the engines of the ninety six hours' trial. I was in and out during the trial, but took no observations of the trial. The feed-pipe is a cast-iron pipe, about five inches in diameter. There was one check-valve on each boiler between the pumps. It was impossible for the water to pass from one boiler to another if the valves are shut. There is a main pipe connecting the two boilers. My reason for not expecting to find any water in the boiler, was owing to the large size of the pipes. I am not quite positive that there was water in the starboard-boiler when I tried the gauge after the explosion. I have not taken any water from the starboarcUboiler. I have charge of the engine at the present time, and have orders not to touch any thing, and do not know what the condition of the boiler is. The water now remaining in the boiler would indicate the amount of water at the time of the explosion. We have, on several occasions, at night, pumped the glass gauge full, and in the morning there would be no water there. Some of the water would evaporate, but not enough to make it entirely disap- pear from the gauge. The engineers in charge of the boilers at the time of the explosion were sober. The reason I said I did not expect to find water in the starboard-boiler was, that I did not know there was a dry pipe on the inside of the boiler. James F. Sullivan. Sworn to before me this 19 tb ) day of April, 1864. j Thomas P. Norms, Coroner. 8 r T. Scott Fillehrown, sworD, says: I am Lieutenant command- ing in the U. S. Navy, commanding the steamer Chenango. I took command on the 14th of November, 1863. She was then in the hands of the contractors of New-York. I left the Navy Yard on the 15th instant, between two and three o'clock, for Sandy Hook, for the purpose of accompanying the Onondaga to the blockade. The accident happened about four p.m., when we were about opposite Fort Hamilton. I had just stepped on deck from the engine-room at the time of the ex- plosion. I had been in the engine-room twice since leaving the yard. Mr. Cahill, the Chief Engineer, was in charge of the engine. When I was down in the engine-room, I asked Mr. Cahill how the engine was running ; he replied that it was working beautifully, and that he was satisfied with the work- ing of the engine. I did not notice any of the indicators. I did not have any other conversation with Mr. Cahill at this time. At the time of my first visit, when about opposite Gov- ernor's Island, I noticed the steam-gauge ; it showed twenty- five pounds of steam. I had perfect confidence in Mr. Cahill, on account of his previous reputation, and his general atten- tion to his duties. My impression ie that there is no blame to be attached to any of the officers of the ship for the explo- sion. I have no reason for attaching any blame to any one. At the time I left Mr. Cahill to come on deck, he was at the foot of the ladder, near his desk. He was about fifteen feet from the boiler when I left him. At my last visit to Mr. Cahill, I remarked to him that when I got on deck where the Pilot was, I would time the ship, and see how long it would take to run to the buoy this side of Sandy Hook. I do not know the amount of steam on the boiler at the time of the ex- plosion. I think the ship was running about eight knots at the time of the explosion. We were running against the tide. I had an impression that the ship when put to her speed would make about fourteen miles. Mr. Cahill said, the pressure of steam would reach forty or forty-five pounds to drive the ship at her speed. I asked Mr. Cahill if he had a good draft; he said he had; there was no occasion to use the blowers. I have heard Mr. Cahill say that it had been necessary to take out 9 some tubes on account of leakage. Never heard him express any fears of the boilers. T. Scott Fillebrown. Sworn to before me this 19th ) day of April, 1864. j Thomas P. JSTorris, Coroner. Thomas F. Brentman, sworn, says : I am a patient in the Ma- rine Hospital. I am a painter by trade. I rendered the scald- ed men all the assistance I could when they were brought in. I have had conversation with William Ware, one of the scald- ed men. I asked him if there was any thing the matter with the boilers ; he replied that he thought it would be so, as they were tinkering them from the time they got steam up until she blew up. Thomas F. Brentman. Sworn to before me this 19th | day of April, 1864. j Thomas P. Norris, Coroner. Henry K. Donovan, sworn, says : I am the apothecary at the Naval Hospital. I had some conversation with Mr. Mur- ray, one of the second Assistant Engineers of the Chenango. After getting through, the worst of the cases, I went through the ward and saw Mr. Murray. I asked him what time the accident occurred ; he said about four o'clock. He said some- thing about feeling uneasy, but I am not certain whether he alluded to the boiler or to his own condition. Henry K. Donovan. Sworn to before me this 19th ) day of April, 1864. j Thomas P. Norris, Coroner. Investigation adjourned to the 20th inst., at 3 p.m. Wednesday, April 20th. The investigation was resumed at 3 o'clock, by Dr. Goodhue being placed on the stand. David P. Goodhue, sworn, says : I am Acting Assistant Sur- 10 geon in the United States Navy Department, attached to the ship Chenango. I was on board when the accident occurred. I saw Mr. Cahill and Mr. Murray both after the accident, I had no conversation with them in regard to the condition of the en- gine or boiler. I never conversed with them about the safety of the boiler. There was thirty -five men scalded as far as I know. Up to the 19th instant there had been twenty-four deaths. The deaths were caused by being scalded on the ship Chenango. I know nothing in regard to the explosion or its causes. Tne habits of the engineers, as far as I had seen, were good ; they were strictly temperate. David P. Goodhue, M.D. Sworn to before me this 20th ) day of April, 1864. j Thomas P. JSTokris, Coroner. George W. Quintard, sworn, says : I am the proprietor of the Morgan Iron Works. I had the contract to build the boilers of the ship Chenango from the Bureau of the Steam Engineer- ing of the Navy Department. Benjamin F. Isherwood .is the Chief of the Bureau. 1 was furnished the specifications for plans, iron, etc. The accompanying schedule is the quality of iron, and the quantity used in the construction of the boilers. I have every reason to believe that the order I gave for the iron was faithfully executed. I think that Wallace & Buckley furnished the iron, but am not sure ; the trade-marks will show who furnished the iron. [The specifications shown to the jury.] I gave orders that the boilers be constructed strictly in accordance with the specifications. I think the stay iron was Ulster iron ; I do not know from whom the iron was purchased. The boilers were properly tested after being com- pleted at sixty pounds hydraulic pressure. There is no certificate to that effect ; we never take a certificate. TJie Government Engineer was present when the boilers were tested. S. Wilkins Craig is the Government Engineer. I have no idea what caused the explosion. I heard of no complaints in reference to the boilers leaking. Mr. Cahill told me a few days before he went to sea that the boilers were very good, and with some little 11 caulking would be tight; he said he would have this done at the Navy Yard. The boilers had steam on for ninety-six hours previous to leaving my place, and were accepted at that time by the Government Engineer. John Walker was foreman of the boiler- shop at the time the boilers of the Chenango were constructed. The boilers are Martin's patent. I am not competent to give an opinion as to the difference between the Martin and Mont- gomery boiler. The acceptance of the boilers by the Government relieves me from all responsibility. George W. Quintard. Sworn to before me this 20th ) day of April, 1864. j Thomas P. Norris, Coroner. George B. Mott, sworn, says : I am Acting Ensign of the United States ship Chenango. I was on board at the time of the explosion. I had a conversation with Engineer Murray after leaving the Navy Yard, on the day we went to sea. The effect of the conversation was that the boilers were not in a fit condition to go to sea. He said they had repeatedly sent to the Morgan Works for men to repair them, but could not get them, and had to put his own men on them to repair them. In answer to a question as how he would overtake a prize, he answered that he would do all he could, but that he had a poor pair of kettles, meaning the boilers. He always made the same remarks ever since the ship had been in commission. Mr. Ca- hill conveyed to me, although not in direct terms, the fact that the boilers were not what they should be. George B. Mott. Sworn to before me this 20th { day of April, 1864. j Thomas P. Norris, Coroner. John Walker, sworn, says : I reside at 1162 Broadway, New- York. I was formerly employed at the Morgan Iron Works, as foreman of the boiler-shop. I superintended the building of the boilers up to the 15th of June, 1863, when I left, I think the boilers were properly constructed up to the time I left. I worked from the drawings furnished me from our office. I think the men in the office worked from the Government draw- 12 ings. I supposed that I was working from drawings and plans furnished by the Government The lugs on the sides of the tube- boxes were riveted. The specifications give no size for the lugs. I made them from my own judgment. The angle-iron was on the boilers when I left. I made it according to the drawings ; it was three and a half by three and a half, and one half inch ; the iron was punched according to the specifications, every two and a half inches. The brace-holes were three quarters of an inch in diameter, and ten inches apart. The entire length of the T iron was eighteen feet; the bar, including the curve, was about twenty-five feet long ; there was eight bars on the boiler ; the boiler was ten feet nine inches in depth. There was but two bars running from each tube-box, making eight in all on the T rail, making sixty-four up and down braces in the boiler. The size of the upright bar were given to me. The rivets in the lugs were two and three quarter rivets. The lugs I put in the boiler were two and five eighths inches, with two and three quarter rivets ; a three-quarter hole was punched for the rivets ; I think the hole was punched cold. The stays were of the same size that I have put in all of the Martin boilers I have built / / think I have built eighteen of them. There was five and one eighth of an inch on each side of the rivet on the upright bar. There were as many stays as the specifications called for. The two and three quarter rivets were supposed to hold the double bearing on the roof. There was double the strength on the roof to what there was on the tube-box. It would have been stronger if the braces had been attached to the tube-box by a half-moon brace. The boilers were made the same as boilers have been made before. The iron now shown appears to have been used as a lug, and is such a one as was put in the Chenango boilers. In staying boilers the braces are put ac- cording to the amount of steam required to be carried, I was instructed to make the boiler bear a pressure of sixty pounds to the square inch, cold water. I place the braces every eight inches square s for sixty pounds of steam. I can not tell the number of square inches on this boiler surface.' There is thirteen thousand eight hundred and sixty square inches of flat surface in the boiler. In a surface braced every eight inches, it would give two hun- dred and sixteen braces to the boiler. The plan of this boiler 13 would not admit of braces being put in this way, in consequence of there being no way of getting through the lube-boxes ; this is the Government plan, not mine. Thirteen thousand eight hundred and sixty inches multiplied by sixty pounds of pressure, gives eight hundred and thirty-one thousand six hundred pounds on a flat surface ; that divided by sixty-four, the number of stays, would give each stay a pressure of six and a half pounds, ex- cept what fell on the T iron. / consider' the brace adequate to sustain six and a half tons weight. I do not know of any acci- dents that have occurred on boilers constructed on the same plan as the one in question. I am not certain what quality of iron was put in the boiler, by reason of not noticing the brand of the iron. I do not know whether Ulster iron was used in the boiler or not. I do not know any thing in relation to the quality of the stay iron. The plate iron was good ; there was some of them thrown out that is flange iron. The specifica- tions for the boiler were made out in the drawing-room by Mr. Coryell. The qualities of the iron were stamped on the plate according to specification. I am not quite sure that the brand was on all the plates. I do not remember seeing any cracks in the plate caused by riveting or driving the pin in. The workmanship on the boiler I considered good. 1 have not a very good opinion of the Martin boiler in connection with any other boiler, on account of the difficulty in bracing them. It is impossi- ble to brace them properly. I have another objection to them. They are a bad boiler to repair in case a tube gives out ; you have to haul fires, cool the boiler, and either plug the tubes or put new ones in. I suppose the roof is made high for the purpose of getting the tubes out. The longer they stay in a boiler the weaker it becomes. I think the Martin boilers are more liable to foam than any other boiler. I think there is more liability of the water being driven from the sheets on account of excessive heat in the Martin boiler than in any ordinary boiler. I do not con- sider the builder to blame for any extra foaming where the di- mensions are given. The boiler was constructed according to the specifications of the Government. I was surprised to hear that the boiler had exploded at the amount of steam-pressure on at the time. I think it would be impossible to burst the boiler at a pressure of thirty-six or even forty-six pounds, if it had been 14 tested at sixty pounds hydrostatic pressure. A toiler will stand more pressure from hot water than it will from cold water. The braces on the flat surface of the boiler were closer than the specifica- tions called for. John K. Walkee. Sworn to before me this 20th ) day of April, 1864. j Thomas P. Norms, Coroner. Adjourned to half-past seven p.m. % Investigation resumed at 7.40 p.m. Loitis Shearding, sworn, says : I reside at 583 Fourth street, New- York. I am a boiler-maker, employed at the Morgan Works. I am foreman of the shop. I took John Walker's place. The boilers were finished when I went there, with the exception of putting in the dry pipes, and riveting on the man-holes. I found every thing correct about these boilers, when I took charge of them. I did not see any bad iron or bad spots in the boiler — the flanges were all good. I did not notice the bracing of the boiler. I fitted up the boiler under Mr. Walker. I regarded the boiler a good one when it left the shop. It was put up as well as any boiler that ever left the shop. I do not know any thing about the quality of the iron used in bracing, previous to my taking charge of the shop, as I never took notice of it. They are using the best quality of iron in the shop, since I took charge. I do not know where the iron comes from. I saw the boiler tested with cold water pressure. On the first trial they put on a pressure of fifty-four pounds. It was put on with a pump of three or four inch plunger. The first time we had to keep constantly pumping to keep the pressure on. The boiler that exploded was the one I had reference to. On the second test we got fifty-eight pounds pressure on the boiler. The boiler stood the pressure first rate on the second trial. I have seen the boiler with steam on. I saw the steam-gauge. The first time I saw it there was twen- ty-four pounds, and the second time they had twenty-six pounds. I went aboard the ship to see if the boilers leaked — they required some caulking here and there — and found every 15 thing all tight on opening the furnace-doors. I have not seen the boiler since the explosion. I went all through the toilers, and found every thing all right. If I had found any of the braces out of place, I would have had them fixed. I could not give any opinion about the braces being out of place. I would split the pin if it was not tight in the hole. If it was tight, and in its proper place, I would do nothing with it. One of the engineers of the ship came and asked me to send a man over to the yard, to caulk the boilers, which I done. After the boiler was caulked, one of the engineers said it was all right. He sent after the same man to come a second time, and I sent him. I had no conversation with Mr. Cahill, in relation to the boil- ers. There was nothing but caulking done when I sent a man from the shop. Louis Shearding. Sworn to before me this 20th j day of April, 1864. j Thomas P. Norris, Coroner. William Finney, sworn, says : I reside at No. 6 Manhattan street, New- York. I am a master boiler-maker. There was a piece of the iron of one of the boilers of the Chenango placed in my possession for testing. The piece was taken from the top of the boiler at the point of fracture, and included the rupture. My blacksmith tested the iron. The process of test- ing was heating the iron, and drawing it out, and turning a point on it. The iron in question answers the quality called for in the plans and specifications of Mr. Quintard. It was laid on an anvil, and hit several blows rapidly, whilst cold. If it had been common English iron, it would have broken off. The iron is as good as that usually put in steam-boilers. It is as good iron as should be used, generally speaking. I exam- ined the boiler outside ; it is the usual thickness for that size boiler. I have examined the boiler sufficiently to come to a conclusion as to the cause of the explosion. My impression is that the cause of the explosion was, that there was a greater pressure of steam than the boiler could bear, and the weakest part gave way. I have seen enough about the boilers and gauges to lead me to believe that there was an excess of pres- 16 sure on the boilers. I would consider eighty or ninety pounds a sufficient amount of pressure to cause the explosion. The general appearance of the inside and outside of the boiler, the manner in which the sheets and braces were pulled asunder, led me to the conclusion that there had been from eighty to ninety pounds of pressure on the boiler at the time of the explo- sion. I have not examined the mercury-gauge. There was nothing in the color of the iron that assisted me in coming to the conclusion I did. I looked at the braces casually on Sun- day. The workmanship and materials of the boiler in question will compare favorably with boilers built at any other shop. The brace in question connects the T iron together. The brace now shown might have been joined together at the top of the boiler. The English method of tying flat surfaces overhead is the same as our own — by braces. The stays gave way first in the explosion ; in my opinion, the weakest part of the boiler is the greatest space between the braces, on the flat surface. The roof could give way without the stays giving way ; the rivets may give way, and leave the stays in their proper place. I can not tell which gave way first, the roof or the stays, as one instantly followed the other. The boiler is stayed on the sides with socket-bolts, or tap-bolts. I think the side of the boiler was the strongest, from the fact of its not giving way. I generally leave a space of six inches in a locomotive-boiler. If I had a flat space of ten feet surface on a boiler to stand a pressure of sixty pounds, I would put the braces eight inches apart. I would place them further apart on particular occa- sions. In my judgment, the top of the boiler was sufficiently braced to bear the pressure intended to be carried. I did not measure the distance between the braces. If the flat surface was not braced, and a pressure was put on to raise the centre three or four inches, it would, of course, damage the boiler. The braces could have been put closer together. It takes about twenty-five or thirty minutes on a locomotive-boiler. It would take about one hour, under favorable circumstances, to get twenty-five pounds of steam on the boiler that exploded. It might instantly run up from twenty-five pounds to eighty or ninety pounds. I did not hear Captain Fillebrown testify yes- terday. The engineer might have opened the throttle-valve, as soon as the captain left him. The result would be a certain 17 rising of the water, and, falling bach to its former position, would cause instantly an increase of pressure beyond the strength of the boiler to resist, and an explosion might instantly follow. In my opinion, a Martin boiler is not any more liable, judging from the number that has been built, to cause accidents than any other boiler. A flue-boiler would be less liable to foam than a Martin boiler. The boilers are made low from necessity. The space from the ivater-line to the roof is higher in other boilers than in the Martin boiler. The water is not so easily carried off in other boilers as it is in the Martin pattern. In the merchant service we are not confined to the height of steam chimneys. The reason why water escapes when foaming takes place in these boilers is, because the dry pipe is closer to the water-line than it is in other boilers in the merchant service; and where there is a difficulty in getting up a supply of water, this upper waste of water is greater than the supply. Under these circumstances, the water will certainly get low in the boiler. If the water came over with the steam, the engine would indicate it. It would have a trembling motion. A few rivets or caulking leaking is no evidence of a boilers weakness. The damage to the wood- work is about the same as I expected to find it. The water-gauge in a boiler that foamed would not indicate truly the amount of water in the boiler. There is no doubt but that the boiler was foaming at the time of the explosion. The furnace-tops do not indicate that they were red hot. A boiler will sometimes foam, and the furnaces not indicate it. I would not consider the builder at fault, if he complied with the specifications. William Finney. Sworn to before me this 20th ) day of April, 1864. J Thomas P. ISToeris, Coroner. Thomas S. Cunningham, sworn, says : I am a First Assistant Engineer in the United States Navy. I was acquainted with Mr. Cahill, one of the engineers of the Chenango. I had con- versation with him in regard to the boilers of the ship. He was apprehensive of trouble with the tubes of the boiler. The tubes formed a heating surface. He said he had found one of 2 18 them had been cracked in the expanding of it. It is a trouble- some matter to stop a leak in one of the tubes, and the water from them would stop the draft. He did not speak of any other faults about the boilers. A danger might arise from the leakage of the tubes, but I never anticipated any. Thomas S. Cunningham. Sworn to before me this 20th ) day of April, 1864. j Thomas P. Norms, Coroner. Adjourned to Thursday, April 21st, at three p.m. Examination resumed at 3.15, Thursday, April 21st, 1864. W. W. Wood, sworn, says : I am a Chief Engineer in the United States Navy. I had a general supervision of the boiler now under consideration, in connection with the construction of the machinery. My instructions were to have them con- structed, both as to material and workmanship, in the most thorough manner, in conformity with the specifications ; addi- tional to which I received instructions from the Secretary of the Navy, through the General Superintendent of Contracts, in relation to the bracing of all boilers under my inspection being constructed for the Navy Department, in reference par- ticularly to the bracing, which I communicated to the Local Inspector. This is a copy of the letter from me to Mr. Zeller, the Local Inspector, under whose directions the boilers for the Chenango were constructed. I also received sketches of all the braces used in bracing the boilers. I have never seen the boiler in question. The pressure for any number of stays less than seventy-nine would be addition- al to the number less seventy-nine. I can answer the question in relation to the fact of the boilers being more closely braced on the side of the boiler than on the top, by looking at the specifications. [Specifications sent for.] I have not seen the rapture in the boiler. / think it is not possible to blow up a boiler with less pressure than sixty pounds, after the boiler has stood a cold-water pressure of sixty pounds. 19 Q. (by Coroner.) If the boilers of the Chenango did bear a cold-water pressure of sixty pounds, and then were used in the ordinary way for four days, is it possible to blow up with less than sixty pounds ? A. Not with the same conditions under which they sustain- ed a sixty-pounds pressure. Q. (by Juror,) According to your calculations, about how much pressure per square inch would carry away the stays ? A. If the iron of which the stays were made was capable of sustaining a strength of fifty thousand pounds section-inch of area, tbey should bear safely one-sixth of that strain, which would be 8333 T Vo pounds. They could bear this safely, and might probably bear fifty thousand pounds. Eepeated strains on the brace would tend to make them yield after the max- imum degree of tension they were capable of sustaining was reached. Q. (by Juror.) The brace being brought up near the breaking point, do you think it would continue to bear that strain ? A. Not after absolute yielding had taken place. Q. (by Juror.) Do you think the riveted lug to the side of the tube-box was at all adequate to sustain the strain from the four points on the roof of the boiler ? A. The relative strain in these several points of contact in this brace, so far as resisting the strain imparted to them, will be to each other as their various "cross-sections. The section of metal in the lower brace which yielded is inferior or less than the sections in the upper attachments. Q. (by Juror.) Do you think that the lower portion of the brace attached to the side of the tube-boxes adequate to sus- tain the amount of strain that the points of attachment above would sustain ? , A. I think not. Q. (by Juror.) Do you not think that an arch-stay riveted at two points would not have been much stronger ? A. It would be stronger, in proportion, to any increased section. Q. (by Juror.) Looking at this rupture, would you in future recommend people to use such a stay as the one in question ? A. I should recommend a modification in this method of 20 bracing at this particular point. However, at thirty-five pounds working pressure I should think this method reliable. Q. (by Juror.) Did the rupture, in your opinion, precede or succeed the parting of the stays ? A. My impression is that the stays yielded an instant, or perhaps an inappreciable amount of time, preceding the rup- ture of the shell. Q. (by Juror.) If the fracture of the stays preceded the rup- ture in the roof, does it not follow that the rupture in the roof was not the cause of the explosion \ A. The cause of the explosion, in my opinion, was from a pressure accumulated in the boiler greater than what could be sustained by the stays and bracing, and of necessity the rup- ture was the result, as before stated in a previous answer — the stays yielded momentarily preceding the rupture in the shell. Q. (by Juror.) From your general experience of the Martin boiler with vertical tubes and fire outside of the tubes, and what is known as the Monitor boiler, with horizontal tubes and fire inside of the tubes, in your opinion is the one boiler any more dangerous than the other ? A. In properly constructed boilers of either type, I should consider little or no difference, in equal management. William W. Wood. Sworn to before me this 20th ) day of April, 1864. j Thomas P. Norms, Coroner. Miers Coryell, sworn, says : I reside at 322 East Sixteenth street, New-York. I am a machinist and engineer. I was in the employ of the Morgan Iron Works at the time the boilers in question were constructed. I had the general superintend- ence of them. The boilers were tested in my presence. The testing was superintended by Mr. Craig, the Government Engineer, by hydraulic pressure. The boilers were subjected to a pressure of fifty -eight pounds on a gauge above the top of the steam chimney, giving about sixty-five pounds at tJie bottom of the boiler. The' boiler stood the test, which was witnessed by Mr. 21 Craig. I saw the boiler afterward, with steam on, at the dock. I believed them ample to sustain three times the required pressure, which, I think, was thirty-five pounds. Q. (by Coroner.) Would not the steam whistling out of the mercury-gauge give sufficient indications that the pressure was above fifty pounds ?. A. Some of the mercury would be blown out also, and the steam would certainly make a noise. There is about twenty- two pounds of mercury in the gauge. I do not know that the mercury was blown out of the gauge, as I have not seen it since the explosion. Miers Coryell. Sworn to before me this 21st ) day of April, 1864. j Thomas P. Norms, Coroner. S. Wilkins Craig, sworn, says : I am a Second Assistant En- gineer in the United States Navy. I was ordered to superin- tend the testing of the Chenango's boilers. In obedience to a clause in the specifications, the test must be in presence of a Government Inspector. I personally inspected the boilers. The order was to test them at sixty pounds , which is twenty-five pounds more than they are permitted to carry. The boilers were tested twice ; the first time we had a gauge on the top of the steam chest — it is customary to place the gauge on the bottom ; but it was handier, and we made allowance for the difference in the height of the column of water, about seven pounds. The boilers did answer the requirements of the specifications ■,* and I reported to the Navy Department favorably. I saw the boilers with steam on. I think twenty-seven pounds was the highest pressure on them. Q. (by Coroner.) Can you tell whether the braces were placed in the boiler, according to the specifications ? A. I received the boilers after the steam chests were com- pleted and most of the braces in. I examined the boilers to- day, and they are not braced according to the specifications.* The braces for each piece of T iron were fastened to one lug * This witness contradicts himself on a very important point. The reader must judge whether he was influenced by fear of the powers that be while on the stand, or was wrong in his opinion of the capacity of the boiler while inspector. 22 on one tube-box, instead of two lugs on each tube-box. It would have increased the strength of the braces had it been put in according to the specifications ; but if the lug, riveted as it has been on the boiler, had been equal to the strength of two lugs, the strength would have been nearly equal to that required for such a brace. The piece shown is not equal to the strength of the two braces. S. Wilkins Craig. Sworn before me this 21st ) day of April, 1864. j Thomas P. Morris, Coroner. Henry Mason, sworn, says : I reside at 23 Scammel street, New-York City. I am a machinist and engineer. I had charge of the Chenango on her trial of ninety-six hours. I had a great deal of trouble in keeping water in the boiler on the trial ; the water ivorked out of the boiler. Sometimes it would take the third of the cylinder of water out. I have had it dis- charge so heavily as to stop the momentum of the engine. The wa- ter went into the condensers, and from there into the air-pump, and from there it went overboard. The discharge at sometimes would be half the size of the delivery -hole, and then it would not discharge again for two or three hours. The water struck the piston. The deficiency is made up by salt-water communication, and from the salt-water part of the condenser to the fresh-water part. I burnt about eighteen tons of coal in twenty-four hours on the trial. The engines made about eight and a half revolutions^ minute, with a pressure of twenty-five pounds to the square inch. Indicator diagrams were taken to show the horse power, by Mr. Bell, a draughtsman in the Morgan Iron Works, i" filled the mercury- gauge full, until it run over. After we fill the gauge we tie a string to the brass indicator, and place it to — — zero on the scale. I consider the boiler not safe in ordinary hands, as the heating surface is too great for the quantity of water contained in the boiler. We had to blow off salt water occasion- ally. The engine has the surface-condenser. The object of the condenser is to transform all the steam into water, and re- turn it to the boiler again ; this condenser accomplished this object to a certain extent. 23 Q. (by Coroner.) If the boiler foamed so as to fill the cylinder one third every stroke, would not that have been sufficient to smash the engine, or prevent her from turning her centre ? A. It is sufficient to stop the engine completely. Q. (by Coroner.) If the water from foaming came into the cyl- inder, one inch within the range of the stroke, would that not be a proper cause for stopping the engine ? A. The relief-valves would relieve it sufficiently to let her pass over the centre. I would not continue to work the engine under such circumstances. Q. by the Coroner. When there are dry pipes inside the boiler, does not that in a great measure counteract the rushing of water and steam into the cylinder? A. It does in a measure. I was on board the Chenango last Saturday afternoon, and looked at the upper part of shell. I did not look at it sufficiently to enable me to form any opinion as to the cause of the explosion. I did not look at the mer- cury-gauge. As an engineer, I have thought the explosion was caused by an insufficiency of water in the boiler, which might have been caused by water being discharged into the condenser from the boiler. Another cause is that the engin- eer might have thought that he had feed-water, whilst the leakage in the boiler would waste a portion passing overboard. A skillful and attentive engineer would not have been -likely to have been deceived. This "boiler worked off more water than any I have had hold of, of late, even for the Government service. It would be difficult to keep a boiler that worked water like the boiler in question supplied. Under such circumstances, the danger of an explosion would be great. I can not say that that was the cause of the explosion, although that is my impres- sion. In my opinion a Martin boiler is not as safe as a boiler with horizontal tubes. The glass gauge would indicate that foaming was taking place. A good engineer will be always able to tell when his boiler is foaming. Henry Mason. Sworn to before me this 21st ) day of April, 1864. \ Thomas P. Norris, Coroner. 24: William H. Wallace, sworn, says : I reside at No. 21 Green avenue. I am an iron merchant. The iron for the Chenango and the Ascutney was furnished by the firm of Wallace & Buckley. The best quality of iron is usually ordered for ma- rine boilers ; it is known as C No. 1, and C H No. 1. I fur- nished some of both grades. The qualities of iron shown by Mr. Gr. "W". Quintard was furnished by Wallace & Buckley. Wm. H. Wallace. Sworn to before me this 21st ) day of April, 1864. j Thomas P. Norms, Coroner. Adjourned to half-past seven p.m. Examination resumed at half-past seven p.m. George Biggin, sworn, says : I reside at 120 Cannon street, New- York. I am a machinist. I am employed at the Mor- gan Iron Works. I assisted in running the Chenango ninety- six hours. The boilers held their water very badly / they foamed considerably. At one time the piston came down on the water on the bottom of the cylinder, and forced the rod into the piston a sixteenth of an inch further than we were able to do it in the shop. We commenced running with open throttles, but was com- pelled to shut off for my own safety, as she made water so rap- idly. This was objected to on the jpart of the engineer. One of the engineers who was at work with me said, that, according to specifications, that I was compelled to run the engine with the throttle wide open. I stated to him that I should use my own judgment about the matter. I considered it dangerous to run the engine. I was in dread the whole time I was on the ship. There is a handle to let off water in the cylinder, as a part of the starting-gear. I did not keep fresh water in the boiler, as we were compelled to blow to heep the brine down, but I never could keep it down on my watch, and at the same time run the boil- ers with safety. I never saw the handle I spoke of rigged on any vessel before. I think I saw the mercury -gauge filled. The glass tell-tale was at zero in the scale. The most pressure I ever had on the boiler was forty pounds. I consider it dangerous 25 to have a foaming boiler, as I do not consider myself compe- tent to tell where the water is, and I use all exertion to get the water down. I consider the Martin boiler more liable to foam, with my experience, than any other marine boiler. I think the water is more liable to be suddenly converted into steam and thrown from its level, in the Martin boiler, than any other boil- er I have had any experience with. Some of the tubes in this boiler are so placed as to receive the intensity of the fire, while others are exhausted. This is not the case with boilers hav- ing horizontal tubes, I think. I have not seen the boiler since the explosion. I think the heating space in the Martin boiler is more than the water space will allow, drawing as it does the steam from so near the surface of the water. The foaming takes place or commences at the crown-sheet ; the most dan- gerous foaming commences there. If the foaming took place in the tubes, I think it would have a tendency to rise, the heavy substance being below. Gr. B. RiGGiisr. Sworn to before me, this 21st ) day of April, 1864. j Thomas P. Norris, Coroner. Joseph Belknap, sworn, says : I 'reside at 156 "West Twelfth street, New- York. I am an engineer. I examined the engine and boilers of the Chenango on the twentieth instant. The size of the boiler is about sixteen feet one way, by ten the other. Q. What is the number of square inches in the boiler as shown in the drawing, that requires to be stayed ? A. One hundred and sixty feet ; twenty-three thousand and forty square inches. I did not notice the number of stays in the boiler — at the rate of three hundred and sixty inches to a brace ; twenty-one thousand six hundred pounds to each brace. I think the brace shown capable of sustaining a pressure of twenty-one thousand pounds. I would suspend twenty-one thousand pounds on the brace shown ; but I would not like to trust in a boiler, because the braces would not all draw alike in a boiler ; more strain would come on one than on another. Boilers are usually braced from six to twelve inches apart, from thirty -six to one hundred and one hundred and forty-four flat sur- 26 face, to sustain the different pressures. Angle iron would help to stay it, or T iron on the side. The T iron shown in drawing has probably run down very near the tube-sheet, about twenty- two feet. I think the length of rail in question would be apt to spring with the pressure at forty-five pounds, without the braces. The rail being elastic, and the brace non-elastic, the strain would not entirely come upon the brace ; the two com- bined forming a stronger brace than either would singly. Q. Looking at the' drawing, you find eight spaces for stays to be placed in front of the boiler, and the same number length- wise of the boiler — would not the strain come upon thirty-two lugs instead of sixty-four, as shown in the drawing? A. It would. If there were only thirty-two lugs instead of sixty-four, as required, the pressure the thirty-two would have to sustain would be double. Q. (by Coroner.) If a boiler is contracted for to stand sixty pounds to the inch, and the boiler is tested, and does not yield, do you think the builders in any way responsible for any ex- plosion which may occur ? A. I do not. Q. (by Coroner.) After the test of sixty pounds, is it possi- ble to explode it with less 3 until some change has been made ? A. No, sir. ' Q. Is it not possible for a change to take place, in putting a hydraulic pressure on a boiler? as it only remains on a mo- ment, it may strain something, which may give way at some other time. A. In a boiler properly stayed, every iron is supposed to be fast to iron. The elasticity of the bar is the safety of the boiler, as the iron is capable of a certain degree of elasticity, without fracture. The elasticity of the bar will allow the braces to come to an equal strain without pressure. In my opinion they have been at work in the boiler, and have de- tached some of the braces, and neglected to readjust them ; that may have caused the explosion, I have not examined the interior of the boiler. If, on an examination of the boiler, I found that opinion an erroneous one, I could only say that I think there was too great a pressure on the boiler. There is nothing on the brace shown that would indicate excessive 27 heat had been applied. If the brace had been heated, it would show it in some cases, from the water being low in the boiler. This brace does not show that appearance. I have given the plan of the Martin boiler considerable study. I have super- intended two boilers of the same style. I have never heard any opinions expressed against the safety of the Martin boiler. I regard them as safe as any other, if they are made of good material and properly braced, for an ordinary pressure of .steam. I saw the rupture on the shell of the boiler. I think the explosion was caused by an excessive pressure, which parted the stays, and ruptured the shell. The piece of iron now shown as a piece of the boiler of the Chenango, is, in my opinion, good iron ; also the iron of the braces is good. I do not think the explosion was caused by a defective sheet of iron, if the piece shown was a part of the boiler. Joseph Belknap. Sworn to before me, this 21st / day of April, 1864. \ Thomas P. Norris, Coroner. Edw. Farron, sworn, says : I reside at 197 Schermerhorn street. I am an engineer by profession. I am at present Su- perintendent of the Morgan Iron Works, New-York. I had nothing to do with the construction of the boiler of the Che- nango. I have examined the boiler since the explosion. I no- ticed the fracture on the shell. In my opinion the iron shown is good boiler -iron, better than is generally used in boilers. I exam- ined the fracture as far as I could see ; did not see any iron that I thought defective. It appeared to be a fracture from the rivets. I did not see the mercury-gauge, but I examined the tell-tale. The mercury would blow out at fifty pounds pressure. If the mercury had blown out at fifty pounds, the steam would cause a noise that any experienced person would notice. Q. (by Coroner.) Do you think the boiler exploded (judging from the mercurj^-gauge) at a less pressure than fifty pounds ? A. It is a question difficult to answer, as no person could tell, under certain conditions of the boiler, what length of time it might take to generate a pressure sufficient to explode the boiler 28 before that pressure could reach the mercury-gauge. It would take a considerable time to raise the pressure from fifty to sixty pounds, so that it could indicate upon the gauge. Q. (by Coroner.) Do you think, judging from these circum- stances, that the boiler exploded under a pressure less than sixty pounds? A. I do not think it would. I have never heard any discus- sion in relation to the bracing of this boiler. Q. (by Juror.) If the inspector discovered that the stays were not put in according to specifications, would it not be his duty to reject the boiler before the explosion ? A. The inspector should have discovered any defect in the construction. My impression is that it must have been some- thing extraordinary to have caused the explosion. If the braces were put in as the inspector stated, two braces leading to one lug on the tube-box, instead of two, I think the strength of the single lug was anticipated to withstand a much greater pres- sure than that supposed to be upon the boiler under ordinary circumstances, and I think that the section of iron left in the lug being one inch by five eighths, that its breaking weight could not? been less than forty thousand pounds, being equal to sixty-four thousand pounds per square inch. On Monday, one week ago, I asked Mr, Cahill how every thing was on board the ship. He said every thing was all right. I think the Mar- tin boiler is a safe boiler. I do not think them as safe as a cylin- der boiler. The engineers having the Martin boiler in charge have found fault with them in regard to foaming. The general opinion of the Martin boilers is that they do foam more or less. Mr. Cahill was considered a careful man as far as I know. Edw\ Farron. Sworn to before me, this 21st ) day of April, 1864. j Thomas P. Eorris, Coroner. Adjourned to Friday, at three p.m. Examination resumed on Friday, April 22d, at three p.m., by calling Thomas L. Smith, M.D., says : I am a naval surgeon, hav- 29 ing charge of the Navy Hospital in this city. I was on duty when the men from the Chenango were received, and have been since that time. Up to this date twenty-eight have died of the effects of the explosion. They died from scalds and the inha- lation of steam. Thomas L. Smith. Sworn to before me this 22d ) day of April, 1864. j Thomas P. Nokris, Coroner. Henry Hoffman, sworn, says : I am a master boiler-maker. I partially examined the damaged boiler on the Chenango. My examination extended principally to the outside of the boiler. I did not go inside of the boiler. The piece of iron taken from the shell of the boiler was subjected to a test. I was present when the piece was tested. I found it was a fair sample of iron used for that purpose. I did not notice any iron on the entire surface of the fracture that was defective. To the Jury. I consider myself competent to build a boiler. I have taken the leading part in constructing many, both ma- rine and stationary boilers. I have examined this boiler suffi- ciently to enable me to form an opinion of its workmanship and mechanical construction. I would say that the boiler of the Chenango was a fair sample of the Martin boiler used by the United States Government. Q. (by Coroner.) What do you think of the mode in which it was braced ? A. I think it is sufficiently traced for the purpose for which it was intended. I have stayed boilers where the stays have reached from twelve to fourteen feet. I never saw a boiler in England ; my only acquaintance with the English boiler is from reading. The mode of staying adopted in the Chenango's boiler I approve of. Q. (by Juror.) Do you think it the best mode of bracing a boiler to combine the T iron with the rigid brace, to depend upon the two jointly to sustain the boiler? A. I do, in a boiler of that form. I have been employed on boilers of a similar form. I would not consider the braces suf- ficient, in my own judgment. 30 Q. What distance would you put your braces apart on a flat surface to sustain a pressure of from forty to forty-five pounds ? A. Every ten inches square ; but I would not put them less than fourteen or fifteen inches apart if the surface was strength- ened with T iron. I gauged the shell iron in question ; it was five-sixteenths of an inch thick. I have not thoroughly studied the theory of explosion. I have formed some slight opinion of the cause of the explosion. In my opinion the explosion was caused by a deficiency of water in the boiler. I account for the deficiency by the boiler foaming. The Martin boiler is more liable than some others to foam. I do not consider that the Martin boiler should be intrusted to an engineer of not more than ordinary skill. I base my opinion for this upon there being a superabundance of heating surface, which has a ten. dency to create foam, which makes the boiler work water into the engine, suspends the water in the boiler, thereby causing overheating of the plates next to the fire, thereby endangering the safety of the boiler. I have not noticed any thing about the gauges on the boilers of the Chenango. In my opinion, any other tubular boiler that has the same proportions of fire surface as the Martin boiler equally as dangerous. I would consider any horizontal boiler with equal amount of heating surface, as dan- gerous. I think no other boiler of this class has the same amount of heating surface as the Martin boiler. Henry Hoffman. Sworn to before me this 22d ) day of April, 1864. j Thomas P. Norms, Coroner. Frank J. Bell, sworn, says : I reside at ISTo. 227 Sixth street New- York. I took the indicator diagrams from the Chenango, while running ninety-six hours. The two cards shown were both taken by me during the ninety-six hours' trial. They are indicator diagrams, indicating the power of the engine at that time. They left my possession within a few days. The figures showing the pressure of steam vacuum and revolutions are in my handwriting. They are the true statement of the facts at the time they were taken. The extreme pressure as indi- cated on the diagram will not coincide with the gauges. There 31 was an extreme pressure of nineteen pounds indicated on the cylinder by the indicator. I did not look at the mercury at the time I took the figures. At the time the diagrams were taken the pressure on the cylinder was nineteen pounds; the pressure on the boiler was twenty-six pounds. The engines worked well most of the time. I frequently heard the piston strike the water, but can not say whether I took the diagrams in question at that time or not. There was very few naval engin- eers present during the trial. I did not see the boilers tested. Frank J. Bell. Sworn to before me this 2 2d ) day of April, 1864. f Thomas P. Norris, Coroner. John Dolan, sworn, says : I reside in North Second street, near Second street. I am a boiler-maker. I was authorized by the Coroner to go aboard the ship Chenango, and examine the ruptured boiler. I went aboard, but there was no one there to give me any information. I found the man-hole plates on the boiler. I asked for a wrench, but could not get one ; so I could not see the inside of the boiler. I asked for a lamp, and was told that no lights were allowed on board. I examined the boiler as well as the opportunity afforded. I measured the T iron on the top of the boiler, from centre to centre, and found that it was twelve inches apart. 1 did not see any thing on the boiler that would indicate had iron. The iron now shown I consider better than is now generally used. The brace now shown is made of iron as good as is generally used. The force necessary to produce the condition of the brace must have been very great. If the boiler had been tested at sixty pounds cold-water pressure, I do not think that any less pressure of steam could have exploded it. The explosion, in my opinion, from the testimony I have heard, was caused by a scarcity of water in the boiler. I would account for the scarcity of water from the fact that the engineer was compelled to blow the engine down. The boilers foaming somewhat, more or less, they have opened the furnace-doors suddenly, and cold air passing through the furnaces, the water found its level — the top of the tube-box thus becoming bare of water. I think the boiler in 32 question is a safe boiler, but do not consider it as safe as any ordinary boiler with the same attention, because the construc- tion is different. The heating surface of the Martin boiler is more extensive than any other boiler made, resulting in making it an unreliable boiler, requiring more attention. I do consider the Martin boiler as safe as any other, if properly attended to. I think the boiler in question requires more attention than other boilers. I think it safer for the Government to employ practical engineers, rather than theoretical ones. The Martin boiler should not be left in the care of young or inexperienced engineers. Q. (by Coroner.) Do you think the boiler-plate in question is tested in the best way it can be tested ? A. I do. There are many ways of testing boiler-iron. I usually, when I test a piece of boiler-iron for a test purpose, put it in the fire, and knock it down on the corner of the an- vil. I can not say any thing about the usual way of testing iron taken from an exploded boiler. From my mode of test- ing, I think the iron shown would be capable of sustaining all the pressure necessary. A man that is not competent to take charge of a Martin boiler is not, in my opinion, fit to have charge of a steam-engine. John Dolan. Sworn to before me this 22d ) day of April, 1864. J Thomas P. Norms, Coroner. Thomas F. Powers, sworn, says : I reside on the north-east corner of Myrtle and Clermont avenues. I am an engineer, machinist, and inspector of stationary steam-boilers. I ex- amined the boiler of the Chenango on the outside. I ex- amined the mercury-gauge. There was about five inches of mercury blown out of the gauge, if the gauge was filled at the time it was put up. Blowing out the mercury proves that there was an over-pressure ; the mercury would not blow out of the gauge if there was not a sudden over-prqssure. There was not any water in the pipe leading from the boiler. That proved that there must have been a heat in the tipper part of the boiler. There was a quantity of water blown through the mercury in the gauge. The tell-tale was about two and a half 33 inches above zero. The gauge on the tell-tale should have been at nothing, (0.) The absence ©f mercury is, in my judg- ment, an infallible proof that there was too much power on the boiler. I examined the shell of the boiler where it was rup- tured. I did not notice any defective part in the iron. I have formed an opinion of the Martin boiler. I think they require a great deal of attention and care ; but the English horizontal or tubular boilers I think require just as much care. I think they require so much care, from the great amount of heating surface ; the steam space is small, and the water space is small. The boiler requires care and attention. The generation of steam would be so sudden that the boiler must get sudden re- lief to he saved. A boiler with a large heating surface is more liable to work water or foam than others. I would not consider a boiler subject to such changes a safe boiler to adopt for the marine service. The mercury-gauge is about three-eighths bore. There was no mercury spilled on the floor before the gauge was tak- en down. When there is any of the mercury blown out, the pressure being the same, the rest will follow more readily That being the case, and the gauge being only three eighths diameter, it is very possible that the gauge did not indicate correctly. I did not see the safety-valve. I saw no indications of mercury about the floor. I found the gauge all in good working condition, with the exception of the absence of mer- cury. The float would have been blown out altogether if the mercury had risen to the top of the tube. Q. In your opinion, would the float return to its proper place in the tube after the pressure had left ? A. It would. There was a cock on the gauge. I found the water-cock open. The other, I think, was closed. Thomas F. Powers. Sworn to before me this 22d ) day of April, 1864. j Thomas P. Norms, Coroner. Elbridge Lawton, sworn, says : I reside at 125 Oxford street, Brooklyn. I am a Chief Engineer in the United States Navy. 3 34 I am on special duty connected with building machinery for the Government. I have nad a great deal of experience in the Martin boiler, both in their construction and use on board of ships. I have been Chief Engineer on three ships on which the boilers have been used — the frigates Colorado, Eoanoke, and Mississippi. I was in charge on the Colorado six months ; twenty-one months on the Eoanoke, and twenty months on the Mississippi. I did not notice any thing in the boilers dur- ing this time to weaken my confidence in them. I have no- ticed the Martin boiler to foam. There is not any thing in these boilers to make them foam more than other boilers. All boilers foam more or less at times. The Martin boilers are, in my opinion, as safe under ordinary circumstances as other boilers. They are capable of being supplied as fast as any other boiler. I have not formed any opinion about the cause of the explosion. While in charge of the Martin boiler, I have had some forty assistants under me, mostly young men just entering the service — third assistants — and the working of the machinery and boilers was noted on the log-book every hour, and it was my duty to read and approve it ; and I never no- ticed any remarks as to the foaming of the boilers. There never was any complaint made to me about the boilers foam- ing or behaving badly. The boiler of the Colorado had no dry pipe, and if they foamed badly, would work water ; but the engines of these ships did not work water — a proof that the boilers did not foam much. The more rapidly you use steam, the more liability there is to foam. The cause of foam- ing is an undue relation between the pressure of steam and the temperature at which it is formed. The Martin boiler is as liable to foam as the other class. Either class can be so de- signed as to foam badly — putting them under low decks, etc. The steam-room is not contracted so as to make room over the furnaces. We had no blowers in the Colorado and the other two ships in question — only a natural draft. My opinion is that the boiler, if made of proper material and properly stayed, is as good a boiler as can be got. I would prefer it to any boiler in use. There is no difficulty in staying these boilers. The boilers of the Mississippi are nearer alike to the Chenango's than those of the Eoanoke or Colorado. I do not think that 35 the boiler was exploded by foaming, taking into consideration the testimony of Engineer Sullivan, Captain Fillebrown, and the dying declaration of Mr. Cahill, that he had two and a half gauges of water.* I have not been able to form any opinion in relation to the explosion occurring from defective staying, from the testimony I have heard or read. Mr. Sullivan could not judge much of the working of the engines or boiler by being in the pilot-house. Mr. Cahill could not know the height of the water while standing by the cylinder. All I have heard of Mr. Cahill as an Engineer has been to his credit. I would consider myself just as safe managing the Martin boiler as I would any other boiler. I never heard the safety of the Martin boiler questioned. An engine could not work any great amount of water without thumping. I never run a holler of so low a steam-room as the one in question. Elbridge Lawton. Sworn to before me this 22d ) day of April, 1864. j Thomas P. Norris, Coroner. Mortimer Kellogg, sworn, says : I am attached to the United States ship Brooklyn. I am a Chief Engineer in the United States Navy. During my experience as an Engineer, I have had charge of the Martin boiler, with ample facilities to test their principles. On the San Jacinto we had one Martin and one English horizontal boiler. The two boilers in their work- ing did not materially differ. Under some circumstances, (the consumption of fuel,) I would prefer the English boiler. The tendency of the Martin boiler to foam, under my experience, was very trifling. They are, when properly braced, as safe in the hands of an ordinary engineer as any other boiler. In case the water got a little below the water-gauge, I would feel safer with the Martin boiler than the English. My reason for my confidence is that there is a better circulation of water than in the English or some other styles of boilers. The gen- eration of steam, in rising up through the tubes, naturally car- ries the water up with it slowly, therefore covering the tube- sheets with a quantity of water ; whereas in the English boiler, * There is no proof that Mr. Cahill said this. 36 if the water got below the fire-tubes I would not feel quite so safe. I witnessed a trial for economical results of these boilers. I do not remember the exact result, but my impression is that it was in favor of the Martin boiler. I was not acquainted with Mr. Cahill professionally. I consider the iron in ques- tion as being good iron. Mortimer Kellogg. Sworn to before me this 22d ) day of April, 1864. J Thomas P. Norris, Coroner. Adjourned to Monday, April 25th, at three o'clock P.M. Examination resumed Monday, April 25th, at three o'clock P.M., by calling Cyrus H. Hawkins, sworn, says : I reside at 68 First street, '.New- York. I am a machinist. I put up the mercury-gauge on the Chenango, and also on the Ascutney. The gauge now exhibited is exactly like the one on the Chenango. (The wit- ness here demonstrated the manner in which the gauge was filled.) I was present at the filling of the gauge with mercury, in company with Messrs. Mason and Kiggin. The gauge was properly filled until it ran over, so that the tell-tale was at nothing. I was on the trial of the Chenango, (ninety-six hours.) I noticed that the engine worked water very badly. I was called three or four times during a four hours' watch to work the water off the cylinder. When I heard the piston strike the water, I would leave the engine-room, and work off the water. There was no way of telling how much water she worked. I was in the boiler before the trial trip, but did not observe the number of stays in them. I have not been on the Chenango since the explosion. I am positive the gauge was in perfect order during the trial trip. Cyrus H. Hawkins. Sworn to before me this 25th ] day of April, 1864. j Thomas P. Norris, Coroner. 37 Henry Mason, recalled, says : I placed the mercury-gauge on board the Chenango, and filled it with mercury. The gauge was filled to overflowing, and was in perfect working order. I was on the ship on the sixteenth instant, but was never inside of the boiler. The steam was six or seven feet higher than the cock on the gauge. Henry Mason. Sworn to before me this 25th \ day of April, 1864. j Thomas P. Norris, Coroner. EdmundS. Be Luce, sworn, says : I am Chief Engineer of the Brooklyn Navy Yard. I have in my possession two indica- tor cards that were picked up on the Chenango directly after the accident occurred. They indicate thirty four and a half pounds of pressure, gauge indication. This is probably the last card that was taken. This indicator shows that the engine was partly throttled. These indicators were found on the floor, and were handed to me by Captain Fillebrown. I have had experience with the Martin boiler at sea. I was in the Brook- lyn nine months, and had charge of the Iroquois eighteen months. I never had any trouble with them. The morning the Chenango came up to the yard, I found the safety-valve at thirty-nine and a half pounds, which is the pressure per square inch that would have opened it. I also examined the cyphon-gauge. I detached the pipes to clear it of water, and pulled the string down, and allowed it to go back ; after per- forming this operation several times, it went back one quarter of an inch beyond zero point. There was no mercury on the floor. I made no further examination, as I did not wish to take it down. There had been no cleaning up before I went on board, as orders had been given not to touch any thing. I did not shorten the cord of the tell-tale. My opinion is that the braces have not been evenly set, and have given way un- der an undue strain. I know, from observations made, the number of braces in the boiler, but I have them at my office. I think the lugs in the boiler might have been built stronger. Boilers are usually stayed much stronger than is necessary to bear the strain. If the boiler was braced according to the 38 drawing, it would show that it was braced to sixty-four lugs. I can give the exact number by going to my office. The Brook- lyn, 's boilers are not as low as the Chenango y s, I never had any trouble working water on the Brooklyn. The Brooklyn draws steam from the chimney. Q. (by Coroner.) If this boiler had stood sixty pounds hydraulic pressure, and pronounced perfect, would it be at all likely to have exploded at a less pressure ? A. If some of the pins had been partly broken, it would be possible for the boiler to have exploded after standing a sixty pound pressure. , Q. (by Coroner.) Is the water-gauge an infallible indicator of the amount of water in the boiler, under all circumstances? A. It is not. At every stroke of the engine there is a re- bound upon the boiler ; in this case it is probable that an ap- proximation to a rupture would be increased at every stroke of the engine. A brace put in connection with an elastic bar brings the strain almost entirely upon the rigid brace, less the amount to spring it. Q. Assuming the gauge to be perfectly adjusted, would it indicate, foaming or otherwise, the exact quantity of water in the boiler? A. 1 think it will, if kept clear. The forward arch of the Chenango boiler has been very hot. Edmund S. De Luce. Sworn to before me this 25th ) day of April, 1864. j Thomas P. Norms, Coroner. Warren E. Hill, sworn, says : I reside in Greenpoint. I am an engineer and draughtsman in the employ of the Conti- nental Iron Works. I examined the injured boiler on the Chenango on the 20th instant, for my own gratification. I went inside of the boiler. I examined the stays; there was sixty-four of them in the boiler. The boiler is generally braced as shown in the drawing. The braces to the roof are half-moon braces, attached to T iron, which is three and a half inches square by one half inch. The half-moon braces 39 are one and one-eighth inches, attached to a bar one and three- quarter inches by three-eighths, running to the tube-boxes, to which they are fastened by two three-quarter rivets at different angles, somewhere about an angle often degrees. I made the number of braces as sixty-four, coming to the tube-boxes. There are one hundred and sixty square feet in the top of the •boiler to be stayed, making twenty-three thousand and forty square inches, making three hundred and sixty inches to each brace, making a pressure of twenty-one thousand six hundred pounds to each brace. We generally brace boilers of this kind every nine or ten inches, making one hundred inches to each brace, I do not know why the boiler was braced on the top every three hundred and sixty inches, while this and all other boilers are usually braced at one hundred inches. I would look upon it as a very strange piece of boiler-making. I think, an elastic T rail would help strengthen the boiler. Warren B. Hill. Sworn to before me this 25th ] * day of April, 1864. J Thomas P. Norris, Coroner. William Bromley, sworn, says: I am Chief Engineer of the Fulton Iron Works. I have had experience with the Martin boilers. I was on the ships Niagara and Brooklyn about six days each, also the Oneid-a and Iroquois. I have never had any cause to complain of their working. I suppose the boil- ers of the ships I have named were like the boilers on the Che- nango. The drawing shown is about the same as the others. I have noticed these boilers to foam, but. not more so than other boilers. A majority of new boilers are liable to foam. The water-gauge would not indicate the true amount of water in the boiler, if the boiler was foaming. There would be more or less fluctuations in the gauge during foaming. I was one of a hoard of engineers who sat in judgment last winter on the boilers, engines, and condensers of these gunboats, called by the Secretary of the Navy. The Board was composed of the following gentlemen : Mr. E. Everett, Miers Coryell, Charles M. Copeland, William Wright, Yon Merrick, B. Bartol, Mr. Hibbard, and Mr. Loring of Boston ; five of the Board reported 40 favorably. There was a minority report. This report was only based on the economical effect. The* report was printed for the use of the Board, and copyrighted. The Martin boiler can be made as strong in every way as the horizontal tubular boiler for marine service. My confidence in them has not been shaken by the recent disaster. William Bromley. Sworn to before me this 25th ) . day of April, 1864. j Thomas P. Norms, Coroner. Augustus K Baker ) sworn, says : I reside in Providence, R I. I have charge of the construction and running of the engine of the double-ender Pawtuxet. She was built from plans and specifications furnished by the Government. The drawing shown is the same as the one the Pawtuxet boilers were built on. I had charge of the Pawtuxet on her ninety-six hours* trial. She burnt about fifteen tons of coal an hour. She averaged six and three quarter revolutions a minute. The diagram shown is the one taken on that occasion. During the trial we had a great deal of foaming of the boilers. We had to open the relief- valves very often, to let the water which came over out of the cylin- der. We had to feed salt water to make up for the loss. I do not consider it safe to run the boilers with the engine, as they will foam in spite of all you can do. The vessel was tried a week ago last Saturday down the river. We carried about eighteen to twenty pounds of steam on the trip. The throttle was about three eighths open when we had twenty-two pounds of steam. On going back we opened the throttle wide open. A report was sent from the fire-room that the starboard-boiler was foaming. I examined the boiler and found it was foaming very bad. We was then near the end of our trip. I ordered the fireman to draw the fires at once. I was twenty -iiuo minutes getting water up to the first gauge. I do not consider the boilers as safe as any other boiler with ordinary care. I do net con- sider them as safe as the common tubular boiler. I do not think you can brace the flat surface in the Martin boilers as well as you can other boilers, as you can not put braces enough in to hold them. The water-gauge does not show the amount of 41 water while a boiler is foaming. I think any engineer would be liable to mistake and not know where the water was during foaming. An engineer could tell if there was plenty of light, and his boiler was not foaming, at a distance of fifteen feet, how much water he had. In my opinion, the cause of the explo- sion has been from the overheating of the crown-arches, which would cause an. increase of steam pressure instantaneously. I base my opinion on the testimony of former witnesses. The overheating of the sheets would result from lack of water in the boiler. I commenced my business at thirteen years of age, and have been engaged at the business ever since. I would not make a report to the Captain that every thing was working beautifully if the boilers had been foaming. The engineer could tell at a distance of fifteen or twenty feet if the boiler was foaming. If there was a good light I could tell if the boilers foamed by the working of the engine. I would not ha/ue risked myself in the Pawtuxet if Iliad not had full con- trol of the engine. I do not consider the boilers fit to run with the engines that are constructed to run with them. A. E. Baker. Sworn to before me, this 25th \ day of April, 1864. ) Thomas P. Norms, Coroner. Henry Nones, sworn, says : I am a First Assistant Engineer in the United States Navy. I have had an experience on sev- eral ships with the Martin boilers, over a period of eight years. My experience has been satisfactory. I have never noticed any variations that I would consider dangerous, with proper attention. I do know something about the staying of these boilers, as I have paid a great deal of attention to them. The number of braces I do not recollect. I looked in the boilers, and I think I counted seventy, but will not be sure. They were braced exactly, I think, according to this drawing. I should say the Ascutney boilers are braced similar to the Che- nango's. I have never discovered any strain on any of the braces, or an appearance of giving way. I had charge of the Ascutney during her trial. I was Chief Engineer of the ship. 42 The engine and boilers were in charge of the engineers fur- nished by the Morgan Works. I, with the assistance under me, obtained the necessary data for the government during the trial Of ninety-six hours. The general working of the engine was good. The boilers at times gave some little trouble by foaming. On several occasions I worked the relief-valves myself, being near them. During the trial the engine worked water y how much I am unable to say. The piston struck dis- tinctly. I did not consider this dangerous, so long as the valves were large enough to free the cylinder of water. The valves did permit the water to pass out. I should not antici- pate any danger from the fact of the engine working water. Henry B. Nones, Jr. Sworn to before me, this 25th ] day of April, 186i. j Thomas P. Norris, . Coroner. Adjourned to half-past seven p.m. Examination resumed at half-past seven P.M. by calling C. L. Carty, sworn, says : I am an Engineer in the United States Navy. I kept watch on the Pavvtuxet on her trial of ninety-six hours. I did not notice any thing particularly wrong, except that she lifted her water slightly, not sufficient to inconvenience the working of the ship. The water-gauge is not a true indicator of the water in the boiler, if the boiler foams. The gauge may indicate two and a half cocks, and the boiler may have more or less. I believe the Pawtuxetfs boil- ers are the same as the Chenango 's. I have had about sixteen or seventeen months' experience with the Martin boiler. I do not know that they require more care than other marine boil- ers. A foaming boiler is hardly safe for marine or other pur- poses. The most prominent causes of foaming are the different waters, salt and fresh, one requiring a higher temperature to boil than another. It is rather more difficult to keep a fresh supply of water on a boiler that foams than any other. I have always felt safe with the Martin boilers. Never had sufficient trouble to make me feel otherwise. I think the boiler of the 43 r Chenango had been injured by cold-water pressure, making it unequal to the task intended for it. I think I would consider myself safe with a boiler that had stood a pressure of sixty pounds, cold-water pressure, at a steam pressure of thirty-five pounds. I should think, if the lead outside the boiler had been melted, that there had been fire in contact with it. I would, taking the piece shown as a sample, think that it had been sol- dered. The piece of felting shown seems too much scorched to have been done by the solder. I think a boiler could be in- jured by a cold-water pressure and not be noticed at the time. Charles L. Carty. Sworn to before me, this 25th ) day of April, 1864. J Thomas P. Norris, Coroner. Thomas H. Faron, sworn, savs : I was master machinist of the Brooklyn Navy Yard for four years. My experience only extends to the use of the Martin boiler at the wharf and some few times on a trial trip. From my observations I have never had any doubts of their safety. I think the boiler is more in- clined to foam than other boilers. I have formed an opinion in relation to this explosion. There is a large body of water above the surface, which is the greatest evaporating surface in the boiler. The steam generated there, that large body of water on the plates has to make its way to the upper surface of the boiler, which tends to lift water along with the steam. The piece of lead shown looks as if it had been partially melted ; the piece of felt appears to have been subjected to a high tem- perature. It must have a temperature of three hundred to have scorched the felt. It would have taken a temperature of five hundred or six hundred to have melted the lead. Such a temperature could have been reached by the upper tubes be- coming bare of water. The steam would have become sur- charged and produce such a heat. From all this, it is my im- pression that the boiler in question ran short of water. Water- gauges are fallible. If I had been told that gauge had indicat- ed a sufficiency of water, I would think there had been some- thing wrong with the gauge. Foaming would produce such a result, but not to such an extent as to cause an explosion, if 44 the gauge was properly placed on the boiler. The iron shown I think is very good iron. The brace shown I also think is good iron. I would consider a boiler safe at sixty pounds steam pressure that had stood a cold-water pressure of sixty pounds. A boiler includes all of its appurtenances, braces, etc. There is not a greater amount of water over the furnace in the Martin boiler than in the horizontal or English boiler. I think the English boiler has not the same obstructions from steam passing around the tubes as the Martin boiler has in passing through the tubes. If I did not find a more extended scorched surface than the sample shown would cover, I would think that the scorching arose from an accidental circumstance, and not from the over- heating of the boiler. It might be possible that the scorching could have been done when the fires were drawn after the ex- plosion, if the lead and felt had been on the edge of the boiler. I have not been aboard of the vessel. Q. (by Coroner.) If the heat of the boiler was so intense as to scorch the felt and melt the lead, would you not expect to find some evidence on the top of the furnaces and on the braces ? A. It is not probable. Q. What would be the effect on the water in the tubes, the fire coming in its intensity against the tube ? A. The tendency would be to start it upward actively, when it would act as a sudden draft of the water over the furnace, by this means giving to the water of the boiler a very active circulation. A rapid circulation of the water would give more safety to the boiler. The steam passing up carries some por- tion of the water with it above the level of the water-line. Thomas H. Faron. Sworn to before me this 25th day of April, 1864. Thomas P. Norms, Coroner. Daniel B. Martin, sworn, says : I reside at "Washington, N. J. I am an Engineer. I was a Chief Engineer and also En- gineer-in-Chief of the United States Navy. I am the patentee of the boiler known as the Martin boiler. I first commenced to build them in 1854. The tubes were then arranged above 45 'I the furnace, the same as they are now. There has been some alterations made to accommodate them to circumstances. The difference between these tubular and other tubular boilers is that these tubes are placed vertically above the furnace, the water passing through the tubes and the heated gases on the outside, the gases first passing through the furnaces and re- turning between and around the tubes. The advantages I claim are, first, the more perfect circulation of water, both for the upward and downward currents; the more perfect com- bustion and mixing up of the gases, those gases coming in di- rect contact with the tubes and passing through between them ; a greater amount of power can be got out of the same space occupied with a greater amount of economy of fuel. The boiler I also consider safer from the liability of water get- ting low in it than the other forms of marine-boilers, for the reason the tubes may be but half submerged in water from the steam generated from the crown-sheet below, and a portion of the tubes submerged in the water will carry up a constant sup- ply of water flowing over the top of the tube on to the tube- sheets. Another reason is, that the metal of the tubes are good conductors of heat ; one half being in the water, the heat will be absorbed by the water below, whilst the other, or hori- zontal form of flues or tubes, has, as soon as the water gets be- low the tube, it has not the water flowing over it, and not coming in contact with the water, the heat can not be carried off by the conductibility of the metal. My boiler can be made as strong as other marine-boilers. Q. (by Juror.) The top of the boiler coming directly over the tube-boxes, and the tube-sheets of those boxes being cut up by the tubing, is it possible to get a perfect fastening for the top of the boiler ? A. It is possible, for the reason that the T iron acting as a truss for stiffening the shell, also for securing the braces to it. Q. (by Juror.) How do you get the fastening upon the top of the tube-box ? A. By riveting to the side-sheets of the tube-boxes. Q. (by Juror.) The brace coming to at an angle, as it must, from the top of the boiler to the side of the tube-box, is it not weakened thereby ? 46 A. The iron would be required to be heavier in consequence. I have not examined the boiler on the inside. Q. (by Coroner.) To what cause do you attribute the ex- plosion ? A. I think the pressure was greater than the braces could bear. Q. (bj Juror.) If the first act in the destruction of the boiler was the parting of the lugs, do you think that it was caused by foaming of the boiler or weakness in the lugs, giving way at a lower pressure even than it was first tested at ? A. I do not think that it was caused by the foaming of the boiler. As I have never known foaming to increase the press- ure in the boiler, neither can I imagine the pressure at which that gave way, but suppose that it would stand to the pressure it was tested at. Should the boiler have been overstrained at that test, it might give way afterward at a less pressure. Q. (by Juror.) Do you think the explosion took place by the water being raised off the sheets and tubes so long as to allow the sheets to get superheated and cause an excess of steam to suddenly flash up ? A. No, sir. The only cause I can ascribe the explosion to is to a pressure greater than the lug could bear. Q. (by Juror.) Do you think the constant surging of steam by the stroke of the engine would cause the parting of the lug, if there was a previous disposition to rupture, at a considerable lower pressure even than tested at ? A. No, sir. The constant working of any thing will have a tendency to weaken in time, and that in proportion to the amount of the injury, if &ny existed, at the time of the first test. Q. (by Juror.) Do you think sixty-four lugs, of the size shown, are sufficient to stay the top of one of your boilers, measuring eighteen feet by ten feet nine inches, at sixty pounds pressure on the square inch ? A. I think it would hold, but if I were building one for myself, I would make it heavier. The iron now shown I con- sider very good. The brace iron I consider extra good iron % (Ulster iron.) The iron being punched cold makes it much weaker than if it had been punched hot. I do not think this 47 was an explosion. I do not believe the rupture was caused by a sudden generation of pressure, but by a gradual increase of pressure. The vessel, I believe, had not been quite an hour from her moorings, consequently she had not had time to evaporate the water, low enough for the steam to come in contact with the heated metals, whereby the steam could become superheated, or surcharged, the water having to be reduced so low, for the reasons I gave in explaining the safety of the boiler ; and as I have heard no evidence to show that the boiler foamed or primed in going down the bay, but, to the contrary, Captain Fillebrown informed me that the engine and boiler were work- ing beyond his expectations. Q. Would not a gradual increase of pressure be gradually indicative on the gauges ? A. Yes, sir. Q. (by Coroner.) Is it likely the engineer in charge would allow the pressure to rise gradually beyond the point of their instructions? A. It is not likely they would ; but their attention might have been called to something else. A burst would raise the decks as found. The damage done is not greater than I would expect from a burst. I have never heard of any complaint about foaming after the boilers had been cleaned out by use. In regard to the dry-pipe, originally, we took the steam from the top of the steam-chimney. The steam-chimney is generally kept very low in a man-of-war; oftentimes, in a heavy sea, the vessel rolling badly, the water would swash up into the steam- pipe. The dry-pipe accomplishes the object for which it was intended, I should think. The dry-pipe was not put in the boiler to remedy any defect from lilting water. I think all the Monitor boilers have dry pipes. Daniel B. Martin. Sworn before me this 25th ) , day of April, 1864. \ Thomas P. Norms, Coroner. Adjourned to Tuesday,' April 26th, 3 P.M. 48 Examination resumed, on Tuesday, April 26th. Miers {Joryell, recalled, says : I was in the employ of the Morgan Iron Works, during the construction of these boilers. To Coroner. The boilers were examined on the inside after being subjected to the test of sixty pounds by the foreman of the boiler-shop, to see if any thing had started. The general plans of the boilers were not discussed, particularly in the draw- ing-shop, before they were sent into the boiler-shop. Q. (by Coroner.) Did you pay particular attention to the mode in which the boilers were to be constructed as intended by the Department at Washington, when the plans came into your hands ? A. The boiler was intended to carry a hydrostatic pressure of sixty pounds, and to that the foreman's attention was di- rected, but I did not give any particular attention to the details myself. I consider myself fully competent to plan and con- struct a boiler in all of its parts. Q. (by Coroner.) Do you understand the construction of this boiler in all its parts and details ? A. I have not seen the boiler since the explosion, but I understand its construction. I do not know the exact num- ber of braces in the boiler, but think there are sixty-two or sixty-four. I do not know how many square feet there are in the boiler that requires bracing. There are one hundred and fifty-four square feet in the top of the boiler, or twenty-two thousand one hundred and fifty-six square inches, giving three hundred and forty-six and two tenth inches to the brace. The stays were generally eight-inch centres, giving sixty-four square inches to the brace. I do not remember ever discussing the subject of the bracing of the boiler with the Government em- ployes, or the heads of the Navy Department. Q. (by Juror.) Did it ever occur to you to compare the brac- ing of the sides of this boiler with the top, and why should the brakes be every sixty-four inches on the sides, while the top was left at three hundred and forty square inches to the brace ? A. The top bracing of a boiler decays but little; the lower braces are very apt to decay. 49 Q. Do you think that sixty-four braces, such as shown, was really sufficient to sustain the top of the boiler of twenty-two thousand square inches ? A. Those braces did sustain the top of that boiler, at sixty pounds, hydrostatic pressure, without the least sign of weak- ness. Q. (by Juror.) Would you, as a good mechanical engineer and boiler-maker, if a friend should come to you and ask you to make him a boiler, would you put no more braces in it than this boiler had in the top of it ? A. I consider the bracing ample / the report of the boiler- maker who examined them after the hydrostatic pressure prove them to he ample. Q. Do you think the braces, when they come to the water- line, will corrode more rapidly between the steam and the water than it does in the lower part of the boiler, where it is always covered with water ? A. It will not. They would not corrode as fast. My opin- ion is that the explosion was caused by over-pressure. To the Coroner. I was one of a Board convened by the Navy Department, to examine into these boilers for gun-boat purposes. The Board made one general report. The report was against the boilers by a majority of one. The boiler was reported unfavorably upon for its evaporative powers, its dura- bility, whether it was always in order for service. I believe it to have been the opinion of the Board generally that, burning the usual amount of fuel, say twelve pounds per square foot per hour, they were not as efficient as other types of boilers before the Board. The report of the Committee was not re- spected hy the JVavy Department. I endeavored to follow out the specifications of the Government in the construction of the boilers. Q. Did the following specification ever come under your particular notice : The shell to be braced at points not exceed- ing twelve inches between centres, with one and a half inch diameter rods, of the best quality wrought iron, and thorough- ly secured ? A. That means in an ath wart-ship direction, as the width of 4 50 the tube-box prevents it in the other direction, and the boiler was so braced. Miers Coryell. Sworn before me this 26th ) day of April, 1864. j Thomas P. Norris, Coroner. Louis Schardirig, recalled, says : I went into the boiler after it was tested at sixty pounds pressure, and had been accepted by the Government. I examined the inside of the boiler, to see if every thing was all right, that nothing had given way ; that was ony business, to see that every thing was all right. I made a perfect examination of the inside of the boiler. I could not find any of the holts started by the pressure. I ex- amined the bolts and pins with reference to the matter. I found none strained like the one now shown. Q. Do you think the boiler was as strongly stayed on the top as it was on the sides ? A. I did not see any difference in the bracing. . Louis Scharding. Sworn before me this 26th | day of April, 1864. J Thomas P. Norris, Coroner. Thomas F. Rowland, sworn, says : I am proprietor of the Continental Iron Works at Greenpoint. I have seen the boiler since the explosion. I have been inside of it. I have examined the stays and braces that were parted. There was sixty-four braces on the top of the boiler, I think. Q. What is the usual number of stays that boilers are stayed with? A. It depends altogether upon the amount of pressure to be carried, and the style of the boiler to be stayed, whether flat sur- face or cylindrical. All flat surfaces require to be equally stayed, for the same quantity and quality of iron, under equal pressure. Q. Did you find this boiler so stayed ? 51 A. I know nothing about the sides or bottom of the boiler. I only examined the point of rupture. Q. What is the distance at which braces should be placed in this boiler to bear a pressure of sixty pounds to the inch ? A. I can not give any opinion without making a mathemati- cal calculation ; and I must decide upon the diameter of the braces and the manner in which they are fastened to the tube- boxes, and to the shell of the boiler. Q. Would the brace now shown sustain a pressure on a sur- face of three hundred and sixty inches, at sixty pounds to the inch ? A. I do not know without making calculation, but can only say, that the iron in question will stand a pressure of twenty thousand pounds to the square inch of section with safety. Q. (by Coroner.) Did you see any thing in your observations and examinations of the boiler to enable you to form an opin- ion as to the cause of the explosion ? A. I have no clear opinion upon the subject. Q. (by Coroner.) Did you come to any opinion upon the subject? A. I think the braces may have been unduly strained by being tested by the hydrostatic pressure. I did not see any thing else that would lead me to any other conclusion. I consider the iron in question of good quality. It is possible for a boiler to explode at any pressure that is in excess of that which the shell is capable of enduring, regardless of the braces. The rent in the shell of the boiler would be apt to take place at its weakest point. I did not notice any thing that would indicate a weakened point along the course of the fracture. I don't think the boiler had to exceed sixty pounds of pressure on it when it exploded. It would require fifty pounds of pressure to hlovj the mercury out. If the chamber was not on the gauge it would flow out at fifty pounds. If the tell-tale was found two and a half above zero, it would indicate a pressure of fifty pounds, plus the one and a quarter pounds that was lost. Q. (by Juror.) Do you not think that if that boiler had ex- ploded with a very high pressure, from one hundred to two hundred, that there would have been a much wider rupture, and a greater displacement of the parts ? 52 A. I do. I think the boat would have hardly got back to New- York. Thomas F. Kowland. Sworn to before me this 26th ) day of April, 1864. [ Thomas P. JSTorkis, Coroner. John Walker, recalled, says : I was foreman of the Morgan Works "up to the fifteenth of June. The plan of bracing was all laid out before I left, but the braces were not made. I suppose the braces were made according to my plan. The boiler was braced according to the Government plan. I did not study the specifications, only the drawing that was furnish- ed me. The drawing shown is the one I worked from, I think. I adopted the size of the braces according to my own judgment. I think it sufficiently strong to stay the boiler for the work it was intended to do. If I did not, I would not have put them there. Q. (by Juror.) Why did you trust the top of the boiler to a brace like the one shown every three hundred and sixty inches of surface, while you stayed the sides every sixty-four inches ? A. There was no T iron on certain portions of the sides to stiffen it; secondly, the sides are more subject to corrode than the top. The T iron was about twenty -five feet, the whole length of the bar. Q. What pressure on the bar do you think would spring it? A. I could not answer that, but do not think a light pres- sure would do it. Q. Wo aid not the strain come entirely upon the brace, less the amount required to spring the bar? A. Yes, the strain would come entirely upon the braces. The T iron forms a roofing or rafter under the shell. The shell would give way first, if an explosion occurred ; the strain coming on the T iron, would be apt to fracture it. I do not think it probable that the boiler gave way at any pressure short of that at which it was tested, without some changes had been made — a brace might have been left loose, or improperly fastened. The looseness of the brace could not take place without some one had entered the boiler to make some repairs, 53 and had unfastened the brace, and neglected to fasten it again. I am not aware that there was any repairs necessary to take any of the braces out. I have superintended the building of some sixteen or eighteen of these boilers, and have braced them all about the same as the one in question. No accident ever hap- pened to any of these boilers before that were braced as this was; they all stood the test in the presence of Government Inspectors. John E. Walker. Sworn to before me this 26th ) day of April, 1864. J Thomas' P. Norms, Coroner. Mr. De Luce, recalled, says : There are thirty-two lugs in 'the boiler. I think twenty thousand pounds is a very high estimate for a piece of iron to resist in a boiler. The part broken amounts to about three quarters of a square inch ,* therefore I would consider fifteen thousand pounds a high strain on a lug for a boiler. The roof of this boiler contains one hundred and sixty square feet ; multiplied by one hundred and forty-four, the number of square inches in a foot, gives twenty-three thousand and forty inches ; that divided by sixty- four, the number of stays supposed to have been in the boiler, gives three hundred and sixty inches to a stay ; that multiplied by sixty pounds of pressure, at which the boiler was tested, would give a strain of twenty-one thousand six hundred pounds upon the stay ; but reducing the lugs to half the number, puts a strain upon the lug of forty-three thousand two hundred pounds, which was considered at an ultimate strength to re- quire only fifteen thousand pounds. I do not think the boiler was properly stayed. Ed. S. De Luce. Sworn to before me this 26th ) day of April, 1864. j Thomas P. Norris, Coroner. Warren E.. Hill, recalled, says: I can not state how many lugs there are in the boiler. I only supposed there were sixty-four braces, from the fact of counting them as they hung 54 In the boiler, and made sixty-four of them in that way. I did not count the lugs on the sides of the tube-boxes. Warren E. Hill. Sworn to before me this 26th ) day of April, 1864. j Thomas P. Norms, Coroner. Henry M. Smith, sworn, says : I am a machinist and engin- eer. I reside 86 Fifteenth street, Brooklyn. I set up and run the engines and boilers of the double-ender Metacomet. She is one of the double-enders that have been recently built for the Government. I had steam on her for the establishment that built her three days before the Government people came there. There was changes made in the setting of the valves after they were originally put up. They worked water so badly that the engine did not work well. I had charge of the ship during the Government trial trip of ninety-six hours, although I had nothing to say about the management of the ship. She run very well for the ninety -six hours, and then was taken out on a trial trip. We brought her back by orders of Mr. Sewell ; the steam-valves had to have more lift, because the engine took ' the water out of the boiler so fast that we could not keep a sup- ply, and had to add salt water. I took her in that state, and delivered her to the Navy Yard. The next day I received orders from Mr. Brooks to replace the valves and every thing else the same as they were in the first place. I done so as nigh, as I could. The danger from lifting water is that the cylinder will work the water from the boiler, and a person will suppose he has more water in the boiler than is really the case. Q. (by Coroner.) Do you consider those boilers safe against the consequence of low water in the hands of such men as the Second and Third Assistant Engineers of the Navy now are ? A. No, sir. Q. (by Juror.) Have you had an equal experience with the Monitor and Martin boilers ? A. I can not say that I have had as much experience with. the Monitor boiler as I have had with the Martin boiler. Q. Do you think that the foaming is as likely to take place in one as in the other, the height being equal ? 55 A. I should think the Martin boiler the most likely to foam. The boilers did not foam or work badly during the three days' trial for the builders. The engine run very well during the Government trial of ninety-six hours. I consider the whole cause of the foaming to be the excessive opening of the valves. H. M. Smith. Sworn to, before me, this 26 th | day of April, 1864. j Thomas P. JSForris, Coroner. Edward JV. Dickerson sworn. Q. (by Coroner.) What is your profession or occupation ? A. I am an engineer. I have learned and practiced the trade of an engine-driver, and am now engaged in building a large amount of steam machinery and boilers of different kinds. I am also constantly and frequently occupied in running en- gines of steamers, and experimenting on boilers. Q. (by Coroner.) Have you devoted much attention to the subject of boilers and their operations? A. That is a subject to which I have paid a great deal of at- tention during the last few years, and under circumstances, at times, where the causes of explosions were the subject of criti- cal investigation, and have had the benefit of the experience of many of the most experienced men in the country in some of those investigations. Q. (by Coroner.) Have you paid particular attention to the machinery of the double-enders, and if so, under what circum- stances ? A. I have, and under these circumstances : When I first saw the general plans of them and their gross defects, I wrote a letter to the Secretary of the Navy on the subject, about February, one year ago, pointing out some of those defects, and foretelling what would be the consequences, which conse- quences have since all been realized ; and that led me to a care- ful and constant observation of their progress and their opera- tions. I knew that they were very dangerous, and as early as January last, at the time of a trial of one of them, the Eutaw, in Washington, I wrote a letter to the Hon. Henry Winter Davis, warning him of the danger there was of going on that trip, and 56 I hold in my hand now a letter from him, received to-day, in which he says, " I remember very well your warning about the Eutaw, and I bethought me of it when I read the catastro- phe to which you refer," which catastrophe is that of the Che- nango, his letter having been written in reply to one from me in relation to that subject. In consequence of my representa- tions to the Secretary of the Navy, a board of engineers was appointed to consider my objections, and I have their report here, in which these boilers, for the purposes for which they were to be applied, were unanimously pronounced inferior by every member, including Mr. Bromley. Q. Have you that report here ? A. I have. (Eeport produced, and an extract read from it as follows :) On the seventy-first page, the question was submitted by the Secretary of the Navy in these words : " Whether they (that is, these so-called Martin boilers) are su- perior, equal, or inferior to others in use, in compactness, dura- bility, efficiency, and proper adaptation to the conditions of the -naval service." The answer is in these words : " On the whole, we are compelled to consider the type of boiler used in these steamers as inferior to the horizontal tubular boiler, which is generally used by other nations and by this country in its mer- cantile marine" Five of that Board, including Mr. Bromley, " object to so much of the foregoing answer as refers to the comparative economy of the different types of boilers, and de- sire to state that in boilers occupying the same cubical space, and excluding all other conditions at slow rates of combustion, the vertical tubular boiler has the greatest economical efficiency and at a high rate of combustion the horizontal tubular boiler is the superior in this respect;" so that this Board unanimously condemned the boilers for every consideration except one, and* that one, they state, is not required in the Navy. I quote again the language : " The requirements of the service, however, dur- ing the past two years have been changed, and the power of obtaining a high rarte of speed, when desired, has become of paramount importance" Notwithstanding that report, the Navy Department is still making large quantities of these boilers. Q. (by Coroner.) Was this report allowed to go out ? 57 A. To the best of my knowledge it has been kept quiet. The Naval Committee in the House of Representatives called for a copy from the Department, but could not get it. Q. (by Coroner.) Can you give us any theory by which we can be enlightened as to the cause of this explosion ? A. I was summoned by the Coroner to accompany the Jury to inspect these boilers, and did so. I had seen a published statement in the Herald of Sunday, that the lead on'the top of the boiler was melted ; and as those first statements of the first witnesses of an accident, before people interested have had time to consider how they will a/void the consequences, are generally true, and as I had foretold, on the deck of this very vessel, the danger she was in, I looked at once for the evidences of superheated steam, and found them abundantly. The lead-sheet had been melted down to a knife-edge, all around the aperture, where the superheated steam first escaped, and I tore and cut with my knife several samples of it, some of which I gave to the Coroner, having marked them, and on one of which the globule of melted lead still adhered. The felt also around the edge of the rupture was burnt to a crisp, as hair or animal fibres will be by superheated steam, and I picked up some pieces of that, which I gave to different people, and one of which I gave the Coroner ; the sample now shown I recognize as one of them. I have also heard Mr. Martin testify that he had picked up a piece of burnt felt from the same place. I examined the wood of the deck in immediate contact with the burnt felt and melted lead, and it was not scorched, nor was it possible that any fire from the furnace could have got there ; on the contrary, the engineer swore that the water poured back again from that same deck — about the truth of which, I have no doubt whatever. That examination left no doubt as to the cause of the explosion on my mind, and I have heard no suggestion from any other witness to lead to any other conclusion than the common and usual one in such cases — that the steam was superheated. Within the last sixty days the steamer United States arrived here from Hartford, having had low water and superheated steam, and exhibited precisely the same phenomenon. The felt was burned, and the solder in the steam-pipes was melted down and ran into 58 the steam-chest by the hot steam. She did not explode, how- ever, as this boiler undoubtedly did, but her boiler was de- stroyed by the excessive heat. After seeing that evidence, I was entirely satisfied as to the cause of the accident, but I re- quested the Coroner to get access below, telling him that the mercury-gauge would tell the story there. After some delay the engine-room was opened, and we went there. At that time I did not know any of the jury, and there were several persons present, among them Mr. Powers, the boiler inspector of Brooklyn, who has been examined. I went directly to the mercury-gauge with him — a number of other persons stand- ing around. He got up on to a box, and adjusted the string over the pulleys, at the head of the gauge, and then sounded the gauge with the float. The tell-tale went up about two and a half inches above the top of the scale, showing that about five inches of mercury — that is, two and a half in each " lug " — had left the gauge, if it ever was full to the zero point. Finding just where the mercury was, I scratched with the end of my rule the place on the board, and then suggested that the gauge should be taken down — my object being to find out what had become of the water, and how much mercury there was in the gauge. This gauge is a safety-gauge, constructed for the purpose of preventing the mercury being blown out bodily, when the pressure of the boiler exceeded the scale, and it has got two safety-checks on it — the one a partition in the bottom elbow of the gauge, not seen from the outside, through which a small hole is drilled, which prevents the mercury from being moved rapidly ; and the other is the bowl on the top of the gauge, which is covered tight, except a small hole, just large enough to let the string pass out. The consequence of this arrangement is, that when the pressure of steam exceeds the weight of the mercury-*— which in this case is from forty- eight to fifty pounds to the inch — the mercury is forced up into the bowl, and the steam blows through it, making a tube for itself in the heavy mercury, just as a spring of water bubbles up through sand, carrying here and there with it a grain ; and as this jet of steam blows through the mercury, it carries with it by adhesion and friction, in fine globules, some of the glo- bules of the mercury. If the blast were continued long 59 enough, it would blow it all out ; but, after a boiler explodes, the pressure falls immediately, and it does not last long in get- ting up. "We took down the gauge, and found the water on top of the mercury on the outside. This water must either have been put there on purpose, or have been blown through out of the one quarter of an inch pipe which leads to the gauge, and which always has water in it from condensation, unless when blown out for the purposes of very accurate observation. This gauge has no handle to the cock to blow out the water, so that the engineer has to use a wrench ; and, in general prac- tice, there is no occasion to blow it out at all. The fact that water was on top of the mercury is as conclusive that the gauge was blown through as the fact that mercury was out of the gauge, if we knew that it was full before the accident. But the water indications are free from the errors that may be sup- posed to exist about the adjustment of the tell-tale of the gauge, for the water must have been blown through the mer- cury with the steam, or have been put in afterward on pur- pose, which I presume no one would suggest as possible. And this silent testimony of the column of mercury, which has no passions, and which donH care for the engineer-in-chief or any one else, is worth more than all the witnesses in the world on the subject of pressure on the boiler / for after an explosion, there generally none survive who could possibly know the facts, and in all cases of explosions undoubtedly the men who are present and in charge think it is all right, or they would not be there ; yet for all that boilers explode all the time. When these facts appeared, I told the Coroner what I now tell you, that it was a plain case of the ordinary kind of which thousands have happened in this country and elsewhere, of an explosion from low water, and that I had no doubt it would turn out that the engineer opened the throttle-valve, and there- by produced the explosion in the usual way, which I will now explain. The testimony since has corroborated that view, and leaves no doubt on my mind of the mode of the operation. The theory now generally received among engineers, and which I have no doubt is true, is this : When water gets low in a boiler from any cause, the surfaces of iron have the fire on" one side, and steam on the other, consequently the heat of 60 combustion passes into the steam instead of into the water, and makes that steam as hot as the time and intensity permit. Mr. Frost, of this city, worked the steam so hot that it made the engines red hot through which it worked, and hot enough to hum felt or melt lead. The felt on the steam chimneys of some of our boilers is burnt by the superheated steam, so that felt can not be kept on the chimneys. This heating of the steam does not increase the pressure in the boiler a particle, but it accumulates a vast reservoir of heat, into which, if hot water can be thrown, by the foaming of the boiler, or other- wise, a vast amount of steam is instantly generated. When this heat thus accumulated is taken up in water, steam must result ; and the quantity that results must depend entirely upon the amount of superheated steam that there is in the chamber, and the amount of hot iron there, combined with the amount of hot water, in a finely sub-divided state, that is brought into combination with them. On this principle, Withered's super- heating process operates ; but the explosion is regulated to a point of safety, and it consists of mixing a stream of super- heated steam with a stream of saturated steam coming directly from the boiler, and bearing with it more or less of water. That very apparatus has been put on one of these double- enders, the Eutaw, and the Government engineers report that they have thereby increased her speed about two miles an hour, and no doubt they have. They think they have got it regulated to safety in that case ; but when it occurs in a boiler without regulation, it is certainly destructive. Hence steamboat explosions always occur, so far as I know, when the engines increase the draft upon the boilers, as when the boat first leaves the landing and is making her third or fourth revolu- tion, which on the Mississippi Eiver is the usual time of explo- sion; and the reason is that when the engine increases the draft upon the boilers, foaming is certain to take place if the organiza- tion of the boiler will permit it at all, as all boilers will, if you overdraw their capacity to supply steam at that pressure. At that moment the water that rises into the hot steam is of itself turned into steam ; and the hot plates also give up their heat, which is not very great in proportion to their weight. This, I say, is the common theory of explosions. Whether it be true 61 or not, one thing is certain, that boilers do explode from low water, and they do explode when you open them. So that the opening of a safety-valve is of itself a cause of an explo- sion, as I heard Mr. Martin and a number of other very ex- perienced men testify to, in a recent case of explosion, in which the boiler exploded, undoubtedly from the opening of the safety-valve. In order to explain to the Jury, in answer to a suggestion of one of the gentlemen, the difference between the effect of very high heat and of comparatively moderate degrees of heat, in converting water into steam suddenly, I have brought Mr. Tyndall's book on Heat, and I refer to the one hundred and seventy-second page. Those experiments are in accordance with the well-known law, that iron, heated above one thousand de- grees hot, will repel water, which will roll over the hot sur- face like shot rolling over a table. Liquids will roll on liquids in the same way, but at lower degrees of heat when water is brought in contact with hot surfaces, or is thrown into superheated steam, it is instantly flashed into steam — as in the experiment shown by Mr. Tyndall. And the quantity of steam which will be made simply depends on the amount of superheated steam in the chamber where the mixture takes place. In running a boiler with low water, if the surfaces be- come red-hot, the water rolls over them in a spheroidal state, but the heat which passes through those surfaces is accumu- lated in the steam-room above, where it exhibits its presence by burning off the felt or melting the lead * and it is a very common thing to melt down the solder of the steam-pipe by this super- heated steam. The force of the explosion of course varies with the quantities which are involved in producing it-; just as one quantity of gunpowder will throw a ball a short dis- tance, a larger quantity will throw it farther, more will burst the gun so that it just falls apart and hurts no one, and still more will throw the fragments of it out of sight. And yet they are all simply explosions. To apply that to this case. This boat left the Navy Yard at a quarter before three o'clock, as has been proved ; at Governor's Island she had twenty-six and a half pounds of steam on the gauge, as Captain Fillebrown testifies ; five miles further the boiler exploded. Immediately 62 before trie explosion, trie engineer was occupied in taking in- dicator-cards in a position where it was impossible for him to know any thing about the water in the boiler. Captain Fille- brown went below, and the engineer said, as the testimony is, that the engine was working better .thail he had expected. That would have been the condition of the engine if she had been working hot steam. An engine works the best when the water is low and the steam is dry. The engine was throttled off, as the cards show, at that time, and the pressure of steam marked upon them is thirty-four and a half pounds on the boiler. That was within one half a pound of the regulation pressure of thirty-five pounds. The Captain said he would then go on deck and take the time of the boat. Now, at that moment, I suppose it is morally certain that Mr. Cahill pulled open the throttle-valves to give her the speed when she was to be logged. [Note. — Here a juror said that he thought this reflected on the moral character of the engineer.] One of the jurors says that this is a reflection on the character of Mr. Cahill. In answer to that I say that that act has no connec- tion with the moral character of any human being ; it is just what any engineer would have done, what I would have done in his situation, if I had supposed there was water in the boil- ers ; and he must have done that about that time, or else opened his fire-doors, whether the Captain came down-stairs or not ; because the boilers had picked up steam from twenty-six to thir- tv-four and a half in five miles, and he had but one of two al- ternatives to prevent the steam from going higher than the regulations — either to open the furnace-doors, or else let the engine work up to its power ; and undoubtedly either he or any other engineer would have preferred to use the steam that his fires were making than to open the fire-doors and cease making steam — more particularly, as they had been going less than nine knots an hour up to that time, according to the tes- timony of the Captain and the pilot's report. I meant no re- flection on the virtue and moral character of Mr. Cahill. If the water was low at the .time when the throttle- valve was pulled open, the boiler was almost certain to explode ; and so familiar is that principle, that when I cautioned Mr. Davis to stand clear from the Eutaw, I told him precisely the time when 63 the danger was — "in opening her;" and the testimony of Mr. Smith here last night shows the same operation exactly on the Metacomet, a twin boat. When the valves lifted but lit- tle, there was but little water worked over from the boilers, but when they set the valves to open wide, which was neces- sary to work the engine up to her power, they could not keep any water in the boilers, and had to re-set the valves so as not to open freely to the holier. Q (by Coroner.) Do you think the boiler burst from a press- ure gradually applied, or from an explosion ? A. I think it is as plain a case of explosion as ever I have seen, not a case of bursting by gradually accumulating press- ure. The inherent evidence in the boiler itself, aside from the fact that there was super-heated steam there, is conclusive to my mind of this. One of the certain indications of an explo- sion, as Mr. Tyndall shows, like gunpowder, is the fact that the boiler gives way in the strongest as well as the weakest part, which is not possible if the rupture resulted from gradu- ally accumulated steam ; for steam increases its pressure more gently than you can load a scale with feathers. It took here an half an hour or more to increase eight pounds, by a gradual increase. In looking at these braces, we find that those lugs that are only five eighths of a square inch of iron strong, were strong enough to shear off two five eighths bolts, as Mr. Max- son testified to-day ; and we have here two of those five eighths bolts, supported on both sides by lugs, and screwed up with a nut, nearly sheared off by a lug only five eighths strong, which did not give way. We have here a three quarters bolt, which took only half the strain which the lug supported, bent up a quarter of an inch, when it was also supported on both sides of the point of draft, and screwed up by a nut. Then we go further, and find a three quarters pin, which sustains only one fourth part of the strain, which this five eighths of iron put upon it in the lug, having the impress of the T iron sunk into it, perhaps the thirty-second part of an inch, and that also was held on each side of the angle iron by the jaws- of a suspender ; and you can see the lump on it where the ter- rific squeeze raised it over the angle iron support that it rest- ed on. Now, I suppose that no man in his senses believes it 64 possible for five eighths of iron under graduaLpressure to en- dure a weight that would sink four of those pins that way, or buckle up two of those three-quarters bolts that supported it ; and I have no doubt that this one three-quarters bolt, placed in a jaw as it was placed, would hoist that boiler out of the ship without parting the bolt. This five eighths would stand about forty-five thousand pounds without breaking, which would be about eleven thousand pounds on the pin that is sunk into the angle iron; and eleven thousand pounds would produce no more effect on that pin than it would on the connecting rod of the engine, in the way of sinking it. Secondly, if this boiler had been carried away by gradual pressure, it would have parted these lugs in their weakest spot, not drawn out through two holes above here more than a quarter of an inch, which two were much stronger than that weakest part ; and then the top of that boiler would have buckled up like a dome, and brought up against the deck, not split from end to end through the strongest section. It is quite a common case for boilers to carry away their braces with steam, and to lift the deck over them, and burst nothing. The proposition that a boiler will stand a pressure of six- ty 'pounds of cold water to-day, and burst with thirty-five pounds of steam tomorrow, is sheer nonsense. The lives of all travelers of steamboats in this country depend xipon the cer- tainty that that is false / for the only security which we have is the fact, that their boilers have been pumped up with cold water to one third more pressure than the steam they carry, which fe the limit fixed by statute law, and under which law no boiler has ever yet given way, unless by low water, or by burn* ing out the steam chimney. I£ it were likely, as Mr. De Luce said, that boilers would blow up after cold-water pressure, we should have a Coroners inquest once a day at least. And our safety in sitting in this room depends upon the fact that those iron rods holding the roof up-stairs do not change their minds or natures, and that God's laws are never suspended in the uni- verse an instant. When an explosion occurs, however, w T ith instantaneous rapidity, the pressure is accumulated so quickly that time enough is not afforded for the weak parts to give way and relieve the strong parts ; just as a cannon-ball, which 65 offers but a very weak resistance compared with the strength of the gun itself, will yet resist enough to burst the cannon, because time is an element in all motion, and in all destruction of matter; and if the pressure accumulates too quickly, the time is not given for relief at the weakest point. This boiler presents those phenomena on every inch of its rupture, be- cause it broke transversely to the angle iron, which made it immensely strouger in that direction than it was in the direc- tion where the angle iron did not run. Those are the inhe- rent evidences that this was an explosion, and not a bursting from over-pressure gradually accumulated ; which two effects are perfectly distinct in their operations, and well known to be so. Aside from those inherent evidences, there are others equally conclusive. The safety-valve, it is proved by Mr. De Luce, will blow off at less than forty. Therefore, if the steam rose above forty, it would blow itself off at the safety-valve, and every one on board ivoidd hear it, and it is well established here that no such effect was produced. It is equally certain that the mercury-gauge was blown through, which required forty-eight pounds, as it Was proved to have been filled. It would have required forty-six, as we saw it and examined it • and yet the water was blown through the mercury and was on top of it. It would have been impossible with the safety-valve opening at less than forty, to have accumulated by a gradual accumulation, steam enough to have exceeded forty-six, even if no living being had been on board to have stopped the generation of steam after the safety-valve had begun to blow. But if it were an explosion, that pressure was picked up instantly, like the explosion of gunpowder. The safety- valve affords no relief although undoubtedly it flew open about the same time that the mercury went out of the gauge, and the deck went up. The succession of events is like that of shooting with a gun ; between the time it is touched off and the object is killed, it is not worth while to hold a watch. It is certain, therefore, if Mr. De Luce correctly states the safe- ty-valve facts, that this explosion was so rapid that no one had time to notice the lifting of the safety-valve, which is the com. mon fact in cases of explosions. Then the boilers being burnt, 66 as Mr. De Luce said, was merely corroborative of the evidences of sitperheated steam, which existed beyond and above that. Q. (by Coroner.) Do you consider these boilers safe in the hands of second and third assistant engineers, such as are now employed in the Navy ? A. I certainly do not ; nor do I consider that organization safe in the sense in which that phrase is generally used, in any man's hands. I believe that in the hands of an experienced and thoughtful man, people would not be killed on those double-enders ; but it is demonstrated here to a certainty, which I do not think will be disputed by any body on any side of the question, when the figures which I shall show you are produced, that these boilers, as arranged and organ- ized, are liable at any time in five minutes to get low-water, and become dangerous — and that the same sort of vigilance is necessary about that organization as is required in walking through a powder-magazine with nails in your shoes. I saw this engine running, as I saw others running, and I then said that a man carried his life in his hands, as was also said by Mr. Kiggin, who was running the engine during her ninety-six hours' trial at the dock. The opinions which I now give as to the danger of explosion on these double-enders, were formed and put in writing before this accident happened, so that I am not a witness after the fact, and they were founded upon these facts, some of which have been proven here. 1st. That working slowly at the dock — not more than nine turns a minute — water came out of these boilers in such quantities that a man had to stand guard constantly to assist the self- acting relief-valves to let it out of the cylinder. I then took the drawing and measured how much water must have been worked over, and here is that drawing, which I should be glad to have Mr. Martin examine, who is here in court, to see that there is no mistake. "When the engine worked water enough to strike the piston, the total amount is sixteen hundred and thirty-eight pounds of water pumped out of the boiler by that engine ; while the quantity of water that the steam which ran the engine required is only about nine pounds of water to a revolution. So that these engines were taking sixteen hun- dred pounds of water and nine pounds of steam at a turn, 67 and 1 could not see how that was a safe operation, any way that it could he used. The clearance and nozzle in this engine at the lower end of the cylinder is fourteen aDd four-tenths cubic feet; at the upper end it is eleven and eight-tenths cubic feet At the Morgan Works the piston was driven the sixteenth of an inch up the piston-rod, by fetching up on solid water. [Here the witness was inter- rupted by Mr. Martin, who said that he could show engines much larger than these, which had not half as much clear- ance.] I agree, however, that there are engines vastly larger that have no such amount to be filled, but that does not alter the fact about these engines. 2d. These engines have a feed- pump nine inches in diameter, and thirty-four inches stroke. That pump delivers seventy-two pounds of water at a revolu- tion, while the engine takes, in steam, only nine pounds; and yet that pump could not supply the water which the engines worked overboard, and they had to use a donkey pump in aid. I hold in my hand the indicator diagram of the Pawtuxet, on which the figures are to be seen, made by me long before this explosion. I wish Mr. Martin to examine it and see if they are not correct. These indicator diagrams show precisely how much water, in the shape of steam, the engine uses, just as a pint-cup will measure the contents of a pail. The amount of coal burned during the trial is also proved, and by compar- ing the two, it is reduced to a perfect certainty how much steam those boilers made, and how much went overboard in the shape of water. The indicator diagram of the Chenango has also been proved before you and her coal. In the one case there was only three and four-tenths pounds of water evapor- ated per pound of coal consumed; and in the other case only four pounds. The boilers, how r ever, if properly arranged, with steam room enough and chimneys, will evaporate, I sup- pose, seven pounds : more is claimed for them. The difference in heat was used up in the water which the engine worked over / and it requires about sixty pounds to a revolution, to take over that heat, and this, you see, agrees also with the other fact which has been proved here, that a seventy-two pound pump is not sufficient to supply the boilers. And here the difference appears between the Martin boiler in 68 the Colorado and her class, and the Brooklyn, and these hollers. In these boilers the dry pipe (so catted, perhaps, because it al- ways wants water) is only about eighteen inches above the level of the water, and when this action, which has been described by Mr. Martin and Mr. Kellogg, occurs, of the rushing up of water through these tubes, it has but a short distance to go to throw that water over the dry pipe ; whereas, in the Colorado and her class there is nearly six feet above the top of the tubes and under the shell, and there is a chimney of two and a half feet above that from which the steam is drawn ; and therefore the difference in the two results. This drawing of the Colora- do's boilers shows pencil-marks made by me long before this explosion, to explain how that water is thrown up. The steam is mostly made on the furnace, and it forces its way out of the pipes, making each one a sort of a squirt-gun / whereas, in this boiler, as arranged by its inventor, Mr. Montgomery, there is a reflector-plate above the furnace which prevents the steam from the crown-sheets from using those tubes to squirt through. Q. (by a Juror.) Could not these reflector-plates be put on the boilers of the double-enders ? A. Yes, they could, and that would make them safe. It would require, however, that the patent fee should be jpaid to Mr. Montgomery, and that would spoil the game. Another fact which shows the danger is this : these boats are about nine hundred tons ; they have two hundred square feet of grate-bars, ox thirty more than the "City of New- York," and the large steamers of Long Island Bound have. You have heard that burning a fast fire on these two hundred feet of bars, this boat was going between eight and nine knots an hour only ; whereas, those big boats, about twice her size, go regularly more than thirteen knots an hour. The immense power of that combustion has got to be used somewhere. It certainly does not drive ■ the boat, and is only used to pump the water out of the boilers, and so keep it circulating through the condenser, and back again ; except, as in this case, where some of it was used to produce a Coroner's inquest. I will give you one comparison by which you can see the certainty of this truth. The very day after this disaster I ran the engine 69 of another ship, called the Oriflamme, over the same track to sea; she is a ship, and not a single-deck boat; she was draw- ing thirteen and a half feet of water, which would sink the Chenango ; she has only one hundred square feet of grates, with the same cubic contents of engine as this ; she ran, with natural draft, all the way to the bar, eleven knots an hour, beginning with fifteen pounds of steam pressure, and never having more than twenty -two; while this vessel, drawing less than nine feet, turning twice the amount of coal, carrying steam from twen- ty-six to thirty four pounds, was only going nine "knots an hour. I propose to show you that these defects in these boilers are well known and recognized by the Engineering Bureau which builds them. The Engineer-in-Chief, " under the authority," as is stated in his book of the Wavy Department, published a vol- ume, in which certain statements are made, the substance of which is, that boilers in had proportion, prime or work water badly, and that in such cases a superheating apparatus will to a certain extent remedy that defect. But he says, " There are insuperable objections to the use of superheated steam, even with bad boilers" some of which objections are stated, and the con- cluding one is as follows : "Particularly on account of its dan- ger and the complicated system of val/ves thereby entailed, for provision must be made for shutting it off at a moment'' s notice and resorting to the use of saturated steam." Notwithstand- ing that publication recognizing its danger and the reasons for its use, they have applied that superheating apparatus already to one of these double-enders, and the patentee is here in town now with a large amount of orders to apply this dangerous ap- paratus on other of these boilers ; and he shows now three hun" dred thousand dollars' worth of these orders, which he is now trying to have cashed in Wall street. Q. (by a Juror.) Would not a superheating apparatus placed between the boiler and the engine tend to dry the steam and avoid the dangers of explosions ? A. I think it would not avoid the probability of explosion, but it would put into the organization a chronic condition of superheated steam, which, when the engine was stopped, would make a hot place to create an explosion when it was started again. It would, however, dry the steam, and improve the 70 m speed of the boat ; but it would not diminish the probability of working water from the boiler, because the water is worked from the boiler simply in consequence of the draft of steam by the engine in conjunction with the malconstruction of the boil- er itself, and when the water starts from the boiler it does not know whether it will be pumped through the engine or heated in a superheater. The difficulty is not in the way the steam is used, but in the fact that there is a draft on the boiler which causes the water to foam. The danger of knocking out the cylinder-heads will be diminished ; but there is substituted for it an additional danger, which this book properly describes ; and it is only the substitution of one disease for another, when there is no necessity for either. Q. (by Coroner.) Are the braces in this boiler made according to specifications? A. The specifications prescribe the manner in which, and, in substance, the number of braces which shall be fixed to the top of the boiler, and gives the sizes of the T iron, which is to sup- port the roof; but it does not prescribe the manner or number of lugs which are to secure the opposite end of these suspen- sion-braces. But it requires that the boiler shall be so braced as to stand a cold-water pressure of sixty pounds, leaving it to the discretion of the builder, and to the orders of the super- intending engineer of the work, how the braces shall be secured at their lower ends. In this case it appears that thirty-two lugs were used to hold sixty-four suspenders, which was an amount that, in the judgment of the boiler-maker and of the United States Inspector, was sufficient for the purpose ; and there was no requisitions in the specifications that there should be any more, or as many, provided there were enough to stand the test. When it seemed here that there were sixty-four of these lugs, I calculated the bursting strain, assuming that there was no strength whatever in the roof itself, and it is about one hundred and fifty pounds to the inch. It now appears that there were but thirty-two of them, and it would require sev- enty-five pounds to the inch, if there was no strength in the top, to part those lugs ; and it does appear, as a matter of fact, that the boiler did endure a greater strain than sixty pounds cold-water pressure, so that I say that the specifica- 71 tions were complied with; and it was in the power of the United States Inspector to have ordered one hundred lugs, if he had wanted them, since that point was left to the discretion of the Inspector. Q. (by Juror.) In the construction of boilers, does it not always require a large allowance for the imperfection of work- manship, the unequal drawing of stays, and other imperfec- tions that may occur during the construction of the boiler ? A. It does ; and that allowance is made and provided for here. They have provided to carry thirty-five pounds of steam on the boilers, and they required them to bear the cold test of sixty pounds : that is the margin of safety. In passen- ger-vessels, however, the margin is narrower than that, and sixty pounds of cold pressure entitles, forty -five pounds of steam to be carried, and experience of many years has shown that to be perfectly safe. In the merchant service, in one third of the cases where I have been present, braces are carried away in testing ; but when replaced a certificate is given, and the boilers are considered as safe as if the accident had not hap- pened. Q. (by Juror.) Why do you suppose this boiler was stayed on the sides at every sixty-four inches square, and on the top of it it is braced at every four hundred and eighty square inches ? A. I do not know the mind of the man who designed the boiler, but you could not brace the top every eight inches square, without using the tube-box for that purpose, and tak- ing out tubes, which would be very unnecessary, and would not increase the strength any, provided the thirty-two you have got had a total strength as great as would result from three- quarter socket-belts, eight inches square. Q. (by Juror.) You have stated to us that in looking for the evidences of superheated steam, that you discovered at the point of rupture that the felting was scorched and the lead melted, which was conclusive evidence to you of its presence — would not the entire top of that boiler have shown the indica- tion of scorching that there was at the opening ? A. I did not expect to find any such result elsewhere than around the aperture through which the superheated steam escaped, because the time that the engine had been running 72 with low water, I supposed, was probably not sufficient to transmit the heat through the iron shell, and so into and through the atmospheric space, and beneath the lead, which is an excellent non-conductor ; but I am since informed by a gen- tleman here in court, that he examined elsewhere, and found scorched felt in other places. Q. (by Juror.) Does not felt scorch very easily, and with or- dinary pressure used ? A. No, sir, it does not ; and it is impossible to scorch felt at two hundred and eighty-three degrees Fahrenheit. It is common, however, to scorch felt on the outside of steam-chim- neys, which are„a superheating apparatus, and where the iron often gets red-hot on the inside of the chimney. Saturated steam at thirty-five pounds is about two hundred and eighty- three degrees hot ; it takes six hundred to melt lead ; and I suppose more than that to burn felt. Q. (by Juror.) Would not the water and saturated steam flow immediately through such a rent as this, in sufficient quanti- ties to prevent burning, or the melting of lead? A. The lead is cut down by the superheated steam which comes first ; it is followed in order by the heavier material ; but a jet of superheated steam, or a jet of hot air in a hot blast-furnace, will cut a piece of lead instantly, and that is the test of temperature that is used in hot blast-furnaces. In this case, the edge of the lead over which the steam had blown is cut down to a knife-edge ; whereas, if it had been torn by the rupture, it would show its thickness and be ragged. The heat cuts down the lead to an edge, just as a piece of candy is melted to an edge in the mouth. Q. (by Juror.) Will not all these facts apply to wood as well as to lead ? A. No, sir. The heat which will melt lead will not set fire to oak-wood ; but steam has been superheated by Mr. Per- kins, until it would set fire to wood ; but that can not be done in a steam-boiler, because the heat requisite for that would be so great on the uncovered iron surfaces as to make them soft, and come down. It can be done in an apparatus on purpose. A stick of wood is used to stir melted lead, without charring it ; and the specific heat of lead is extremely small, smaller 73 than mercury, so that it requires the least heat of any metal to melt it. The specific heat of lead is three hundred and four- teen ten thousandth parts of that of water, whilst the specific heat of mercury is three hundred and thirty -three ten thou- sandth parts of water. Wood requires a great deal of heat to heat it, and is, therefore, very slow in raising its temperature, when subjected to heat. Q. (by Juror.) On what basis did you make your calculations that those thirty-two lugs would bear a pressure of seventy- five pounds to rupture the stays ? A. The cross-section of one of those lugs is five eighths of a square inch of iron. The Ulster iron of that lug is warranted to bear seventy-five thousand pounds to the square inch. It will rupture between eighty thousand and ninety thousand pounds. Taking it at eighty thousand for a rupture, these lugs would require fifty thousand pounds to break them ; twenty-two thou- sand pounds was the pressure on a lug, if there were sixty-four lugs, at sixty pounds to the inch. That would be forty-four thousand, on thirty-two lugs, at fifty thousand pounds strength, which I assumed as the rupturing strain, and which disregards the support from the side-arches to the first set of braces, which take half of the strain ; so that the amount I thought to be about seventy-five pounds ; but the pressure it would endure must be greater than that, because when you begin to tighten out these braces, and take the spring out of the half-moon, you bring into action, first, a considerable strength of T iron, and second, you have got the top drawn like a drum-head inside of four support- ing arches, and it requires, like a drum-head, a very large force to budge it out; but as a plain strain, it was about seventy-five pounds when you take the half distance around the edge. / should not he afraid to stand on that holler with seventy-five pounds of saturated steam in it. Q. (by Juror.) If this boiler throws its water out through the tubes rapidly, as described, acting almost as a squirt-gun, and lifting it so that it is ever carried over into the engine, why will not this same operation saturate superheated steam, and prevent the causes of explosion, so fully described ? A. This boiler, like all water tubular boilers, will permit the water to get lower than the top sheet in the tube-box with 74: safety, and during that time, as Mr. Kellogg has correctly said, it will lift the water over that top, and will make it seem at the gauges as if there was really solid water there. That opera- tion in Dimpfell's water tubular boilers is so violent that they have to put a plate over the top of the tubes to keep any water in the boilers. But the limit to that operation is when the water gets very low ; and up to that time the water would be jerking through the tubes, and sometimes fail to go through, as the struggle between that tendency and the diminished supply of water went on. Meanwhile, the gauge would be indicating water at times, and the engine would be getting drier steam continually, until finally the water is too low for that opera- tion, and then the point of danger has arrived. If at that time the throttle he opened, and the demand increased, the water, too low to rise under the less demand, must come up under the greater, and the explosion occurs ; so that this quality up to a certain point is an element of safety against carelessness, but is also the means of deceiving the observer of the gauges, as to the quantity of water in the boiler. The fact of the Pawtuxet case is a perfect illustration, proved by Mr. Baker. He thought he had plenty of water. When he shut down the engine, the water all disappeared ; and, to save his life, he drew the fires from the furnaces immediately, and it took twenty-tioo minutes to pump up water enough to show in one gauge. He was in the same peril as these people here, and that was on the very day after this accident, with the same organization. Adjourned to Thursday, April 28th, at three P.M. Q. (by Coroner.) You say that if the water was low at the time the throttle- valve was pulled open, the boiler was almost certain to explode ; and so familiar is that principle, that when you cautioned Mr. Davis to stand clear from the Eutaw, you told him the precise time when the danger was on opening her. Is this not the case in all boilers? A. Yes, if water is low, and the boiler charged with super- heated steam, the tendency of opening the throttle- valve is to cause the rising of water in a finely subdivided state into the su- perheated steam. I hold in my hand a copy of the testimony of Mr. Martin, in the case of an explosion of a boiler in Connecti- 75 cut, where the mode of operation is correctly stated by him, which I will read as my opinion also : " If pressure is liberated by lifting of the valves, the steam beneath has a tendency to rise and equalize itself, and in so doing brings up water with it. I have seen this in a glass boiler. When water comes into contact with superheated steam, it is suddenly flashed into steam ; the meeting of superheating steam and water makes the power as quick as fine gunpowder." All boilers whatever will permit the water to rise to a greater or less extent, whenever the pressure overhead is relieved faster than the generation of steam will supply it, for the plain reason that in that case the heat which is stored in the water is given off in the shape of steam from the entire mass of water; whereas, when the supply and the demand are exactly equal, there is no change in the total quantity of heat that exists in the water ; but whether that tendency is sufficiently powerful to fill the boiler with foam so that it will overflow the steam-pipe, depends upon the proportion the steam-room and the amount of heat per minute that is expended upon a given amount of surface. Now in this boiler, for illustration, if the steam-room was six feet high, and the steam taken from the top of the steam-chimney, and only about nine pounds of coal were burned per hour upon a square foot of grate, as in the case of the frigates I have mentioned, this foaming tendency would he counteracted / hut in this case the steam is drawn about eighteen inches above the water level, and the fires burn fast, so that the water does rise into the steam- pipe. Q. (by Coroner.) Is the theory of explosions you have given us the one generally received ? A. I believe it to be so among the most intelligent engineers I have known in this country, although we hear people talk about electricity and other mysterious causes ; but one thing is agreed to by all, which is, that low water and opening of the valves do produce explosions. Q. (by Coroner.) Is the tendency to work water inherent in the vertical tubular boiler, or does it depend on the peculiar construction in each case ? A. All boilers work some water with their steam. Mr. Mar- tin, in this same case, testified, I think, correctly, " That what 76 is called pure steam carries about twenty- eight per cent of wa- ter with it ; all steam carries water with it but superheated steam." The tendency to work water is therefore a compara- tive one, and that is not peculiar to vertical tubular boilers, but depends upon their peculiar organization. Thus, the ver- tical tubular boilers in Hecker's mills work no water in the common-sense of that term, and evaporate perhaps more than eight pounds of water into steam to the pound of coal ; where- as, these boilers on the double*enders, as the cards show, get less than four in steam — the last result depending upon had organization of the same general elements which compose the other, and they illustrate what is correctly described in the Navy -Book " as boilers which prime badly from malpropor- tions." Yet if it was considered necessary to put the vertical tubes on top of the furnaces instead of behind or on one side of them, and then to crowd the whole arrangement under these low decks, I do not know how that bad proportion could be remedied. It could be, to a great extent, corrected by a reflect- ing plate over the furnace, as shown on the drawing on the ta- ble. But it is quite obvious that on these vessels exposed to shot, the vertical tubes have no right to be placed on the top of the furnace, for it makes a target of the boiler, and so I wrote to the Secretary of the JVavy about fifteen months ago, Q. (by Coroner.) Could not these boilers have been braced more strongly than they were ? A. Undoubtedly they could, if that had been the requisition of the specification. There would be no trouble in making them stand three hundred pounds to the square inch, if so de- sired, by the use of iron enough. Q. (by Coroner.) What would have been the effect if this boiler had been braced stronger ? A. A much greater destruction than did occur, which is il- lustrated in very familiar cases. On the Mississippi Eiver the boilers generally will bear four hundred pounds to the inch, and they carry one hundred and forty by law. When they do explode the destruction is terrible in proportion to the strength with which it was resisted. A common locomotive-boiler will bear between three hundred and five hundred pounds to the inch, and I saw one immediately after it exploded standing in 77 the shop of the Eogers Locomotive Works at Paterson, with a safety-valve set at fifty. The power which exploded it was certainly not less than four hundred pounds to the inch. The crown-sheet in the furnace came down, and the boiler went up, cutting through two floors, which had two eighteen-inch gird- ers immediately over the locomotive, through another floor and the roof, and it fell back and lodged on the iron arch of the great doorway, whence it was removed by a tackle that had to be sent for from New- York. Great numbers of persons were killed, and the heavy batten doors at the back end of the shop, about one hundred and fifty feet from the locomotive, were blown out of the fastenings, as were all the sashes in the building. Q. (by Coroner.) In view of that fact, how do you account for this boiler keeping its place in the vessel and showing a rup- ture of only about twelve inches ? A. In that case the crown-sheet of the furnace came down, leaving the unbalanced pressure which corresponded with the area of that crown-sheet all acting upward, so that the boiler went up on the same principle that a sky-rocket does. If the top of that boiler had given way, then the pressure would have been directly downward, and the boiler would not have left its place. If the end had given way, the boiler would have shot out of that house'in a horizontal line. The reason why it did so much destruction was that the boiler was im- mensely strong, just as a cannon must be immensely strong in order to do damage. If it had given way at eighty pounds to the inch, it would have done but little injury. In the Che- nango case the boiler gave way at the top, so that the force of explosion was all downward, and the boiler could not have been moved from its place by the explosion except in a direc- tion opposite to that in which the steam escaped, which in this case was directly downivard, and the bottom of the ship prevent- ed the boiler from going through, it being supported by an im- mense surface in proportion to the size of the opening, which measured the amount of pressure which drove the boiler down- ward. In the case in Connecticut referred to, a vertical boiler had the head blown off, and a large house was thoroughly de- stroyed, yet the boiler never stirred from its position, simply 78 because the disturbing force was directly downward on it. On the Mississippi Kiver, however, in the case, I think, of the Helen McGregor, where the engine had been slowed in turning before Cincinnati, and then opened again, some of the boilers went through the bottom of the boat, and some went into the air for immense distances, according as they gave way on the top or bottom. The name of the Helen McGregor I may assign to the wrong vessel, but the accident happened before Cincin- nati. Q. (by Coroner.) This boiler was parted in the centre with great violence. Should not the ends have been displaced ? A. That depends entirely upon the strength of the end brac- ing at the opposite ends. If that were strong enough to hold the ends without the aid of the top, there would be no tenden- cy whatever in the direction of the ends, simply because the opposite pressures at the two ends exactly balance each other ; whereas, the hole being made in the top, the unbalanced pres- sure was all downward. It is precisely the case of a sky- rocket, in which the pressure sidewiseon the paper tube is ex- actly as great as the pressure upward and downward ; but as the confining force blows out downward, and the rocket is strong enough to hold the pressure sidewise, as this boiler was, the whole force of the explosion is spent on the sky-rocket in the direction directly opposite to that in which it has given way. Tarn the rocket point downward and you have the case of this explosion. All the force is spent in pressing down- ward, the opposite sides being strong enough to contain it in a sidewise direction; and if the bottom is strong enough to hold the squeeze, the rocket will stand still. Q. (by Juror.) You have told us that this boiler broke through its strongest section. Is not the weakest section across its length ? A. If the strength of material were equal in both directions, the longer line would be ruptured rather than the shorter one ; but in this case the T iron ran in the direction at right angles to the rupture, thereby vastly increasing the strength in that direction ; since, in order to break the boiler across their line, not only the shell had to be broken, but they had all to be broken, and their strength is about equal to that of the shell ; 79 whereas, if the boiler had split in the opposite direction, it would only have been necessary to split the shell itself, without parting any angle iron ; just as it is easier to split the roof of a house between two rafters than it is to split that same roof crosswise, and to break all the rafters at the same time. Q. (by Coroner.) Is the tendency to explode affected to any degree by the strength of the boiler ? A. Neither the tendency to explode nor the fact of explo- sion is in any way affected by the strength of the chamber in which it occurs ; and no boilers have ever yet been made capable of resisting an explosion when it does occur. Cannon have been made in that way, but that sort of thickness is not admissible on boilers. If .you apply a hydraulic press to a cannon with a ball in it, no appreciable strain can be put on the cannon, because the ball yields to the hydraulic pressure with such ease — the pressure being gradual — that no strain can be induced by its resistance. Now that cannon illustrates the case of a boiler with a weak place in it, and no greater strain can be put upon the cannon or the boiler than the weak place can endure, if gradually applied, whether that strain be of steam or water ; but if you burn gun-cotton in the can- non it will go to pieces, simply by the resistance of that ball, which a child can roll out of it if you give him time. And if you flash an explosion of steam into the boiler, it will, like the cannon, give way, as well in the strong place as in the weak one. Q. (by Juror.) You have told us that the idea that a boiler may explode at a less pressure than it was tested at with cold water is absurd. May not a bar of iron be drawn by a pressure, and thus weakened, and yet not be perceptible to the eye ? A. I presume it may, but there is no connection between that fact and my proposition. Q. (by Coroner.) If the stays of that boiler were elongated by pressure, however slightly, and yet not ruptured, would not the boiler work, and yet be liable to give way under a less pressure £ A. I think not, and for this reason. I think it altogether probable that in most cases of testing boilers some of the stays 80 or fastenings are elongated or bent, but after that, the pressure has come to a state of rest on the boiler, in which the combined strength of all the stays brought into action has been sufficient to arrest the extension of those that were first drawn upon. At that point the strength of resistance equilibrates or exceeds the pressure. If it did not, the whole series of braces would keep on stretching, constantly relieving the pressure, and showing its effect on the gauge ; and if the attempt were con- tinued to accumulate the pressure, of course the braces would give way. Because when you once begin to elongate iron under a strain, it donH stop until that strain stops also, and the time that it takes the boiler, either to carry away the braces or to bring all the strength of the braces into such action as to arrest the bursting force, is vastly less than the time the pres- sure is held on the boiler by any pumping operation. The law on that subject is, that, unless the elasticity of metal is overcome, it will sustain a given weight forever. Q. (by Juror.) In Tredgold, vol. two, page seventy-four, it is remarked that the elastic force of steam or vapor produced by increased temperature ceases to follow the same law, when it is not in contact with the liquid from which it is formed. Again, in page sixteen, same volume, steam at a temperature of one thousand one hundred and fifty degrees is about the same vol- ume of water, and would cause a tension or pressure equal to four thousand one hundred and thirty-seven atmospheres; and in the same volume, page twenty-three, we have Pam- bour's tables bringing down the volume of steam compared with water, in practical effects. I would ask you what you consider a separation of steam from water — is it in a sepa- rate vessel, or can it be surcharged in immediate contact with the water? A. Steam may be superheated, either in the presence of water, or out of its presence ; that fact has no effect on the superheating operation. As, for instance, a red-hot poker put into the steam on the top of your tea-kettle will superheat the steam with which it comes in contact, and it would super- heat it if there was no water in the kettle ; and as the su- perheated steam is specifically lighter than saturated steam, it 81 rises to the top of the other, just as the hot air in this room rises up to the ceiling. Q. (by Juror.) Is it not usual to superheat steam by passing it through a separate heating chamber from that in which the steam was generated ? A. That is not usual, but it has been done in some cases. The Collins Company spent a vast amount of money in trying to make that work. They scalded their fireman on the Arctic in one of their earliest efforts, and gave that up. They spent about forty thousand dollars a piece on the Atlantic and Baltic, to put Withered's superheating apparatus in those ships, and they took them out after about two voyages, finding no advan- tages ; meanwhile keeping their engineers in a wholesome dread of their lives. One of those machines has been recently put in the Butaw, a mate of the Chenango ; thereby largely increas- ing her speed, as it is reported. Those are the only cases I have known in this country ; but I find that there is a large number of them now being constructed by the Navy De- partment, to be put in combination with these boilers, which I have no doubt will make meetings like this more frequent. Q. (by Juror.) Do you know of superheating pipes being placed in the chimney of the Cunard steamers, and if so, state what they are ? A. Yes. I know of them, and they consist of a series of pipes placed in the up-take, through which the steam passes from the boiler to the engine, and which serve the purpose of the ordinary high steam chimneys. They are perfectly safe so far as explosions go, their only danger being their liability to scald a fireman, by being burned out ; although where they place them the temperature is low enough to render that dan- ger insignificant. Q. (by Juror.) Are they heated by fire, or by heat from the chimney ? A. They are heated by the refuse heat which has already been practically exhausted on the surfaces of the boiler, and whose temperature, in ordinary circumstances, does not exceed eight hundred degrees Fahrenheit. Q. (by Juror.) Are they not often enveloped in flame ? 6 82 A. I was never in there with the fire, and have no personal knowledge ; but if it be true that flame often is burning there, the boilers must be worse than I suppose the Cunarders use. Q. (by Juror.) "Would not the gases, at all events, be so hot that they often ignite at the top of the chimney ? A. I have crossed the ocean in the Cunard steamers, and never isaw any such fact as that ; although if such a fact did exist, it would not prove the presence of flame in the up-take, but the contrary. Such a phenomenon, however, is common on the East River boats, driving fires with blowers, which the Cunard line does not use. I would add, however, that where superheating pipes are used in so hot a place, as the gentleman supposes, they are very soon destroyed, and have been aban- doned on account of such destruction — especially in cases where the engine has to be stopped frequently, and where the currents of steam are thus prevented from passing through those pipes. There are patented contrivances, I think, for maintaining an ar- tificial circulation there when the natural one is thus suspended, in order to preserve the pipes. Q. (by a Juror.) Is not that superheating apparatus a separate vessel, heated out of contact. with the water? A. It is not a separate vessel, and the steam is not heated out of contact with water, in the sense in what Mr. Tredgold uses those expressions. What he means by a " separate vessel" and " out of contact with water" is a vessel which does not have in itself any water, or which is not in free communication with a vessel which contains water. The coil of pipes in the case supposed forms a part of the steam -room of a boiler, and is open freely to it. Mechanically it may be called a separate ves- sel, just as a " steam drum" or a " steam chimney" may be called a separate vessel from the boiler, because any of them may be detached, and the boiler be still left. But so long as they are in open communication with each other, the pressure which can be permanently maintained is regulated by the temperature of the surface of the water, and is precisely coincident with it, however hot you may make any particular cubic inch of steam which floats above it in the same chamber. If, however, you put steam in a separate chamber without water, then its pres- 83 ' sure will be increased by increments of beat, in the same manner tbat the pressure of air in a bladder is increased by being held before a fire. Q. (by a Juror.) In your evidence, Mr. Dickerson, that you consider the boiler safe at seventy-five pounds of pressure, which has been stated at about fifty thousand pounds tension on each of the thirty-two stays, looking around us in the shops and manu- factories of the United States, seeing block and tackle used for lifting weights, and hydraulic-presses constructed with columns to resist direct tension, do you still think it was at all safe to put seventy-five pounds on that boiler, without any consideration of superheated steam, but simply of the bursting by the action of ordinary steam ? A. What I said was, that I should not fear the consequences of putting seventy-five pounds of steam pressure on those boil- ers, and I have no doubt that that would be unattended by any danger ; but I did not say, or mean to say, that it would be proper to work these boilers in use so near the bursting strain as that ; but I did say, and now repeat it, that I know of no more certain thing in science or art than that a boiler which would endure sixty pounds of cold pressure is safe beyond a possibility of doubt, to carry forty -five pounds of steam / and I put my life upon that certainty, without any fear, con- stantly, as do all people who travel upon steamboats in the United States. Q. (by a Juror.) Here is a chain having a sectional area the same as the broken stays. In a table of the strength of cables , in Haswell's Pocket-Book, page 258, and in which the proof is stated is from twelve and a half to thirty per cent, greater than what is stated in that table, as requisite for the United States service, it gives the proof strain of nine-sixteenth chain, and the proof strain is five tons, or ten thousand pounds. Here is a chain where the proof strain is rated at twenty-five tons, or fifty thousand pounds — do you still think that there should be such a difference of proportion under the circumstances ? A. I have not heretofore expressed an opinion on the relative strength of chain-cables and boiler-braces, and therefore I do not still adhere to any opinion about their relative strength ; but if my opinion is desired on how strong a chain-cable ought 84 to be, I will give it to you. A chain-cable, like boiler-braces, ought to be made, and I have no doubt is made, as strong as experience has shown to be necessary. Experience has shown, that in boilers, braces need not be more than one-third stronger than the pressure of steam which is required to be carried on them, and therefore both by statute law and by custom, all boil- ers in the United States are constructed on that ratio. Experi- ence has also shown that a ship riding to an anchor slacks up and jerks upon a cable with terrific violence, making it necessary to have that cable many times stronger than would be needed to endure a constant and uniform strain. If aboiler was construct- ed to slack its stays up eight or ten feet, and then jerk them out again as a ship does with its cable, then the same proportions would have to he observed in both cases / but so far as my observation goes, I have never seen a boiler perform in that way. As to whether Mr. Haswell's proportions are correct, as he is an accurate man, I presume they are, and no doubt have been arrived at, by adding by degrees to the strength of cables in use in particular cases where they have broken, until expe- rience has reached the point of safety. Q. (by a Juror.) In chains used in the manufactories of the country, for lifting heavy w T eights, and when they are not sub- jected to the tremendous surging, as in the particular instance stated, do they not follow generally the same ratio of strength? A. I have no idea that people who buy chains follow any ratio at all. I presume, as a general thing, that people buy the cheapest chains that they think will do the business that they want done. There is no law regulating how much weight a man shall put on chains; but there is a law of Congress which has been in force many years, regulating the pres- sure on marine boilers, under which law all marine boilers in the country are licensed to carry three quarters of the steam pressure which they will endure from cold water, and the experience of many years has shown that to be perfectly certain and safe. I have had occasion to use and purchase chains to lift ore out of a mine of which I am the engineer. I selected chains which I thought sufficient for the work. I used them until they wore out and broke, and then bought another, but I never looked at Mr. Haswell's book to see which kind I 85 should buy, there being no law governing those cases. A chain, however, is the weakest possible form in which iron is worked under tensile strain, for reasons well known to engineers, but probably not important enough for this case to be stated in detail. Q. (by Juror.) When Mr. De Luce testified that there was thirty-two stays, when the general impression was that there were sixty-four, and when the Court seemed to pause with doubt at the statement, and some actually disbelieved it until Mr. De Luce was requested to have another witness go into the boiler and testify to the same effect, did you not say : u Of course, if Mr. De Luce's statement is correct, that settles the question" ? A. I do not recollect my precise words, but there was a con- troversy going on between the Coroner and Mr. Inslee as to whether there were thirty-two or sixty-four stays, when I re- marked that the testimony of Mr. De Luce seemed to be con- clusive on that question. I do not remember the precise words, but I remember the idea very well, and I presume Mr. Inslee does also. My remark had no reference to any question except that in dispute at the time, which was, how many lugs there were in the boiler. Before that question was settled, I had said here that « the boiler must have had one hundred and fifty pounds or more on it when it gave way. When the number of stays was settled, of course my view of the explosive force was necessarily reduced in the same proportion. Q. (by Juror.) You would give the jury to understand, then, as the sum of all the facts and deductions in the course of your evidence, that the Martin boiler is dangerous and unfit for use? A. No, sir. I did not say so. I did say, and about that I have no doubt, that the Martin boilers arranged in the propor- tions and beneath the decks of the double-enders, are eminently dangerous in any hands. If, however, the large amount of steam room and steam chimney used on the frigates were ap- plied to them, that extreme dangerous condition in which these circumstances place them would cease to exist, but that is not possible in these low-deck vessels, ^ Q. (by Juror.) The Monitor or horizontal tubular boilers, of 86 which I produce a tracing, are placed in similar circumstances — do you not think they are equally dangerous ? A. Undoubtedly not. They are in effect the locomotive- boilers, and experience has demonstrated that a locomotive- boiler can be run and hold its water with exceedingly small steam room, and without a dry pipe ; while experience in water tubular locomotive-boilers has also demonstrated the necessity of plates situated above the delivery apertures of the water- tubes, against which the water ejected from the tubes can strike, and by which it is driven back, in order to run that sort of tubes on a locomotive-boiler ; and on the three sets of boilers proved here before you, two of which I my- self saw, it is established beyond a question or doubt, that with the throttle-valve and steam-valve working wide open, water can not he Jcept in those boilers except by jumping into them from six to ten times as much water as the steam required for the engine uses. I have run locomotives long enough to know that water will stay in those boilers without any difficulty, and that from six to seven pounds of evaporation can be got out of them in steam to a pound of coal. Edward K Dickerson. Sworn to before me, this 28th \ day of April, 1864. j Thomas P. Norris, Coroner. John Maxson, sworn, says : I reside 94 Gold street, Brook- lyn. I am a boiler-maker for twenty years past. I am in the Government employ at the U. S, Navy-Yard. I went inside of the boilers of the Chenango to examine the braces and the extent of the damage done inside. This was done by orders of Mr. De Luce, Chief Engineer of the Yard. I found thirty-two braces proper, but thirty-six braces all told. Above there was sixty-four stays, but the lug is the brace of the boiler. Q. (by Coroner.) How many tube-boxes are there in the boiler ? A. According to the drawing, there are five. Q. How many T rails are there on the top of the boiler ? A. There are eight. 87 Q. (by Juror.) Is there not coming from the rail to each side of the tube-boxes a brace ? A. There is not ; but they are zigzag, one brace from the rail to each water space only. Q. (by Juror.) Will you point out on the plan how these braces draw from the rail above to the side of the tube -box ? A. Witness explains to the jury, showing but one brace in every three feet nine inches on the length of the rail ; the braces are twelve inches apart the other way. Q. (by Juror.) From the inside of the boiler and personal ob- servation, counting the lugs to which the roof of the boiler is stayed on the flat surface, are there only thirty-two lugs ? A. Yes. Q. (by Juror.) Did you examine the height of the water in the boiler that exploded ? A. I did ; it was sixteen inches below the bottom of the tube- box. This was caused by the rent running so far down on the sides of the boiler, and which extended below the roof of the . furnace. Q. (by Juror.) Would not the boiler in its present condition show a line of water about seven inches below the roof of the furnace ? A. I think it would, in its present state. I have never seen other boilers braced like the boiler in question. Q. (by Coroner.) Suppose you had a boiler tested that had been built under your charge, and it stood sixty pounds cold- water pressure, would you consider that boiler, so far as brac- ing was concerned, safe enough to run ? A. I would consider it safe at forty pounds of steam. I would take into consideration the particular plans of bracing, if I knew the boiler had stood the test of sixty pounds. Q. Then you do not consider the testing of boilers worthy of confidence ? A. I do not. Q. (by Coroner.) If after the hotter had ~been tested at sixty- pounds, you entered it and found the bracing and all of its ap- purtenances unimpaired by the test, would your confidence be strong enough to run the boiler without any apprehension of danger, at forty pounds f\ 88 A. It would. I would regard the braces sufficiently strong for the purposes for tohich they were made. I think there is about one half of the lugs broken, and the remainder half are bolts of braces broken. They are broken like the one now- shown. ^The bolts broken are sheared off. I have been accus- tomed to build these boilers. I have built some twenty-five or thirty. I had charge of the Morgan Works for one year. I generally try to brace them twelve inches square, and more fre- quently eight by ten, with three eighths boiler-iron for the shell. I put the lugs from two to two and a half inches wide, from five eighths to three quarters of an inch thick. Q. (by Juror.) Do you put the braces zigzag, as you have de- scribed before ? A. I put them opposite to each other, and double the num- ber of lugs that I find in this boiler, the braces being suffi- cient in the boiler for double the number of lugs. There is no reason why this boiler could not have been stayed with double the number of lugs. There never was any accident happened to any of the Martin boilers I ever built, with one exception, which was the fault of my workmen leaving out some of the braces. The boilers I refer to were not built for the double-enders. The boilers of the Fulton are the same height in chimney as the Martin boiler. There is more steam-room in the Fulton boilers than there is in the Martin boiler. I think the steam-room is sufficient in proportion to the boiler. John Maxsok Sworn to before me this 27th ) day of April, 1864. j Thomas P. Norms, Coroner. George /Sewell, sworn, says : I am a Chief Engineer in the United States Navy. I was General Inspector. This particu- lar set of boilers were about completed when I assumed the duty of General Inspector. These boilers were subjected to -the required hydrostatic pressure, and were reported to me by the local inspector as in good condition, and standing the press- ure well. The duplicate of that report is in the General In- spector's office, 48 John street, New-York. I also saw these boilers under steam, during their ninety-six hours' trial, at the 89 wharf. * From my recollection, I made what is considered a favorable report of their performance, so far as being tight and working well, a copy of which report is in the General Inspec- tor's office, 48 John street. I never heard any complaints from the Chief Engineer of the vessel, Mr. Cahill. There were several unimportant things complained of after the vessel was taken to the Navy Yard by the Chief Engineer of the ship, Mr. Cahill, all of which I ordered rectified, and which I believe was done, as I have heard no further complaints on the sub- ject. The boilers in particular, I wish to say, were never com- plained of in any manner, shape, or form by the Chief Engineer of the ship, Mr. Cahill. My object in being so particular in my statement relative to the boilers is owing to the fact that I have heard it stated that the Chief Engineer of the ship had ex- pressed his fears in regard to the safety of these boilers. I do not recollect whether Mr. Cahill was on board of the ship dur- ing the ninety-six hours' trial. Q. (by Coroner.) Did he make a favorable report to you of the boilers after he took command and worked the ship himself? A. He made several complaints about trifling things around the engine, but never had any fault to find with the boilers. I asked him on several occasions if every thing was all right and to his satisfaction ; if not, to make out a report to me, embrac- ing those things that did not suit him. He mentioned several not very important things, which I ordered the Local Inspector to have attended to, and which I have every reason to believe was done, never having heard any more complaints. The Meta- comet is one of the same type as the Chenango. I was on board of the Metacomet on the trial, and went down the bay in her, during which trial the engines and boiler performed in a very satisfactory manner. There was no unusual foaming of the boilers, and no unusual amount of water let out of the cylinder through the valves placed there for that purpose, and with the exception of adjusting the steam exhaust-valve to the desired point of operation, the report was highly favorable to the success of the machinery and boilers. The engine made, I think, as high as thirty-one revolutions per minute for a short time, and by the pilot's land-marks, between which he turned 90 = the vessel, he pronounced her as going at the rate of "sixteen miles per hour. Q. (by Coroner.) Were the valves on that trip lifted? A. We stopped once to adjust them, that is to say, give more lead, to enable the engine to pass the centres more smoothly* She lifted no water worthy of note ; nothing unusual for new boilers on an engineer's trial trip. We used a small quantity of salt water on the trip, which will always be the case to a greater or less degree to all vessels fitted with an apparatus to supply the boilers with fresh water, except when an evaporator has been supplied to make up for the loss of fresh water by leaks. There might have been some few unimportant leaks in the boiler, but none worthy of remark. A copy of my report of the trial is now in the General Inspector's office, No. 48 John street, New- York. The valves were not ordered to be replaced by me on the return of the vessel to the Navy Yard, but the alteration was then made a permanent one, so far as the arrangements of bows, lock-shaft, lock-shaft arms, etc., would permit. The arrangements of the last-mentioned things was such as not to admit of the alteration being carried to the extent that I desired ; hence it was somewhat modified from what I desired to do. Q. (by Juror.) Did you expect that the stays in that boiler would be attached to the tube-boxes with sixty-four lugs or thirty-two lugs ? A. I expected they would be attached to the places shown by the drawing for them, and in the number called for, which the Local Inspector, who had the immediate supervision of them, should have had done.' Q. (by Juror.) From examining that drawing of the boiler shown, (Chenango's boiler,) do you expect that the sixty-four braces would be attached to thirty-two lugs ? A. I should consider from the drawing presented that each lug was intended to receive but one brace-rod. Q. (by Coroner.) Have you formed any opinion as to the cause of this bursting or explosion ? A. Yes, sir, I have. From what I have heard from the en- gineers of the navy, who have made a critical examination of the boiler, from some cause or other all the braces did not keep 91 an equal strain or pull, which may be the result of the impro- per fitting of the braces when put in, or may have resulted from some of the braces having been removed after the vessel had been delivered into the charge of the Government, for pur- poses of examination of the boiler. They may have been care- lessly, or they may have been improperly, replaced, care not having been taken to see that each brace was equally tight. If one brace should be tighter than another, or take in more strain, it would be very apt to give way, which would bring an undue strain upon the next brace, and might cause that to give way, which, giving way one after another, must necessarily re- sult in rupture to the shell of the boiler. I have seen one case in particular where the rupture to the boiler was from that cause. Q. (by Juror.) Do you think this bursting took place by an excess of tension on the boiler at a less pressure than it was tested at, and by saturated steam, or do you think it was an explosion caused by excess of heat and deficiency of water in the boiler, so as to be superheated steam ? A. If that Jiad been an explosion, as such things are general- ly understood, the destruction of woodwork and other material in the vicinity of the boiler would have been one hundred times as great as what it is. It is simply a rupture. I was on board of the boat the Monday following the disaster for five or six minutes. I think every thing goes to show that it was simply a rupture, and not an explosion, as the damage to the vessel is very trifling. Q. (by Coroner.) Then you consider it a rupture from satu- rated steam, at a less pressure than the testing pressure ? A. I can not speak of my own knowledge, as I have not seen the indicator-cards, said to have been taken a moment be- fore the rupture, and which indicator-cards are said to show a pressure of thirty-four and a half pounds, and I see by looking at them now, is the number of pounds marked. I do not con- sider that a boiler subjected to a heavy hydrostatic pressure is any evidence that it will not give way at a less pressure than that which it has been tested successfully, as it may be overstrained in some of its parts by that very test, and corre- spondingly weakened. The Chief Engineer has the right to 92 go in the boiler and do as he pleases, so long as he does not destroy any thing. Q. (by Coroner.) "Would such an important transaction oc- cur, as the removal of braces, without some report being made of the circumstance ? A. If the Chief Engineer of a steamer desires to go into the boilers, for examination or any other purpose, it is oftentimes necessary to take down or cast braces loose, to enable him to reach or accomplish the desired object he has in view. After coming out of the boiler, the braces are ordered to be replaced, which is a very important point, be it observed, that all of them are so adjusted as to be equally tight, that each brace may take its due proportion of the strain. If that is not pro- perly done, the boiler is correspondingly weakened. Whether such was the case or not, I am unable to say. Q. (by Coroner.) How comes it that this boiler stood a ninety- six hours' test and several hours' working at the dock before going on her voyage, and not show any defects, if any existed, and at the time of the explosion the indicator-card only showed a pressure of thirty -four and a half pounds of steam ? A. I do not think that during the trial of ninety-six hours that she had a greater pressure than twenty-five or twenty-six pounds of steam to the square inch. If my memory serves me correctly, I think twenty-five pounds of steam is the pressure required to be maintained during the ninety -six hours' trial, but the degree of pressure which would cause a boiler to give way, after having been satisfactorily tested by hydrostatic pres- sure, will depend entirely on how much the material of which it is constructed has been overstrained or injured by the hy- drostatic pressure. Q. (by Coroner.) Would the steam that would produce a burst be hot enough to melt lead and scorch felt ? A. I have seen felt scorched on the boiler of the United States steamer Susquehanna, from a steam-leak under a pres- sure of some fifteen pounds to the square inch. The felt after the shell of the boiler is first in order, and then the lead. Q. (by Coroner.) Would you, then, consider steam at the tem- perature you speak of sufficiently hot to penetrate through that felt and melt down lead to globules ? 93 A. I do not think it would. Q. (by Coroner.) If Mr. Cahill opened the throttle-vale of the Chenango, when the Captain was going on deck to throw the log, would it not be with a view to deceive the Captain in re- gard to the speed of the vessel ? A. If possible, it would be necessary, first, that I should know at what point of opening the throttle-valve was at that time, before I could answer the question intelligently. He ^would be justified in further opening his valve if he had steam to maintain his increased supply. Q. (by Coroner.) If Captain Fillebrown told Mr. Cahill, when he left the engine-room, to go on deck, that he was going to throw the log, or time the ship, and Mr. Cahill opened the throttle-valve after the Captain left the engine-room, what ob- ject could he have had in view for so doing? A. To give the vessel her maximum speed. Q. (by Coroner.) If at the time Mr. Cahill was supposed to have opened the throttle, the water was low in the boiler, what would be the result ? A. From the position of the throttle shown by the indicator- card, it could not have made any difference in its level, as it was open sufficiently to give all the steam that the cylinder could take. Adjourned to Friday, April 29th, at 3 P.M. Examination resumed on Friday, April 29th. Continuation of Mr. George Sewell's examination as follows : Q. (by Coroner.) Suppose the water to be low enough to ex- pose heated surfaces, what would result after such lifting of the water ? A. The result would be an increase of the generation of steam. Under certain circumstances, an explosion would take place, if the boiler had already a very high tension upon it ; if a very large portion of the heating surfaces were unduly heated, an explosion would probably result. Again, if the boiler had a moderate pressure or tension upon it, and a small quantity of tfie heating surfaces were exposed, an explosion would not necessarily result. 94 Q. (by Coroner.) You said that the felt on the boilers of the Susquehanna once burnt so as to be smelled all over the ship, when only fifteen pounds of pressure were carried. I find by the tables that saturated steam at that pressure is only two hundred and sixty-one degrees Fahrenheit hot ; do you mean to say that felt will burn so as to give out the odor of burning hair at that temperature ? A. It actually took place, of which plenty of evidence can be procured. I have never investigated the temperature at which hair will char or burn. There was apprehensions among the officers of the ship, that the ship was on fire. Q. (by Coroner.) Did not that boiler carry more than fifteen pounds, at times, and if so, did the felt burn then ? A. I think that eighteen or nineteen pounds was the limit which she carried ; felt did not burn at those pressures, simply because there was no leakage of steam coming in contact with the felt on the boilers. Q. (by Coroner.) Did not the double-enders in use carry more than fifteen pounds, and does their felt-covering burn, so as to be contracted into a crisp, like the sample shown ? A. I have never seen a steam-leak from any of the boilers of the double-enders that had access to the felt on the boilers. Q. (by Coroner.) I find that the temperature of steam at thirty-five pounds is two hundred and eighty-three degrees Fahrenheit ; will that burn felt to a crisp like this sample? If so, does it do so on the other double-enders you have seen work ? A. I have never investigated the subject as to what degree of temperature, or under what particular circumstances, hair- felt would begin to burn or char. I simply mention what I have seen. Q. (by Coroner.) Is not the melting point of lead six hun- dred degrees Fahrenheit ? A. To the best of my recollection it is. Q. (by Coroner.) When water is low in a boiler — by which I mean so low as to uncover the iron surface below which the fire is acting — is not the steam overhead superheated ? A. It is, to a greater or less degree, depending upon the 95 amount of surface, and the degree of temperature by which it may be overheated. Q. (by Coroner.) In that condition, is there not a danger of explosion ? A. That would depend upon the tension to which the boiler is subjected at the time, and the rapidity with which steam is withdrawn from the boiler for supplying the engine. Q. (by Coroner.) It is proved here, by Mr. Baker, who ran the engine of the Pawtuxet in Rhode Island, the day after this explosion, that he supposed there was water enough ; but when the throttle-valve was shut off, the water was reported to be foaming ; that he at once drew the fires to save his life, and that it required a steam-pump twenty -two minutes to pump water enough into the boiler to be seen in the gauge. Do you con- sider that boiler to have been in danger of an explosion at the time when the shutting off showed the true condition of water? A. I do not, if he hauled his fires at that time. Q. (by Coroner.) Is it any more likely that the men in charge of that engine should have been deceived as to the true state of the water than that the men in charge of the Chenango should have been deceived? A. They may have been less versed in such matters, therefore more likely to have been deceived ; and I consider it a reflection upon any engineering department, in any of the steam vessels that would be caught in that fix, particularly with a new ves- sel, when it is possible to always know, within a very few inches, the water-level in the boilers. Every engineer has it in his power, at all times, to ascertain the height of water in the boiler, by simply shutting the throttle-valve in the steam- pipe and arresting the flow of steam in the cylinders. No mat- ter how badly the water may have been foaming, it would at once settle, or if it does not do so perfectly and to his satis- faction, putting on cold feed-water to the boilers, or opening the furnace-doors for a moment, will be certain to accomplish it. I was on board of the Pawtuxet during her ninety-six hours' trial, at the wharf at Providence, R. I., and I saw no evi- dence of the foaming of the boilers, nor heard any complaints of such a thing having taken place. Every thing performed remarkably well, so much so, that I observed to the contractor, 96 Mr. Gardner, of Providence, that my office was to find fault ; that I was very happy to say that I could not do so in this case. This refers to the ninety-six hours^ trial, not to the trial trip. Q. (by Coroner.) It has been sworn to by Mr. Smith, that he set up and ran the engine of the Metacomet ; that after the trial trip to which you referred yesterday, the rock-shaft was ordered to be so altered as to lift the steam-valves higher than it had done, as it was originally set by him ; and that he did so alter the rock-shaft as to increase the opening of the valves. Do you mean to be understood as contradicting this statement? A. I ordered it done, so to give the necessary opening or passage for steam to reach the cylinder, that the flow of steam might be as ample as the cylinder required, when performing its maximum duty. Q. (by Coroner.) Mr. Smith also swore, that after the change the boat was again run, and the water worked over so badly, that it was difficult to keep the boiler supplied, and that the salt feed had to be used for that purpose. Do you wish to con- tradict that statement ? A. If my memory serves me correctly, and I think it does, there was no trial made after the arrangement was permanently made ; and I have learned since she reached her station in the Western Gulf Blockading Squadron, that the performance of the engine and boilers during the passage was highly satisfac- tory and gratifying. This information was imparted to me by an intimate friend of the Chief Engineer of the Metacomet, who had received a letter from him containing that informa- tion. Q. (by Coroner.) Mr. Smith, also swore that, after that trial, he was ordered by Mr. Brooks, which order he said came from you, to replace the rock-shaft as it was before the alteration, and that he did so, at the Navy Yard. Is that statemeut true? A. I have no knowledge that such an order was given Mr. Brooks. Q. (by Coroner.) About how many of these double-enders are ordered, or in progress of construction ? A. I think there is nine in course of construction now ; a number has been finished. 97 Q. (by Coroner.) Are they all like the Chenango in their engine and boiler ? A. In principle they are all alike, with one exception. Q. (by Coroner.) How many have been already tried? A. Some fourteen or fifteen have made the necessary trials. Some are on their stations. Q. (by Coroner.) About how many are yet in port, awaiting orders or crews ? A. About six. Q. (by Coroner.) It is proved here that these boilers, on trial at the dock, required the salt water to be blown out every watch, to keep down the salt saturation in the boilers. Is that the way that surface-condensers usually operate ? A. I contradict that statement. It was not necessary to blow them down at every watch ; it may be necessary wherein, from defective workmanship, the condenser is not tight, and the salt water is allowed to mingle with the fresh. Q. (by Coroner.) Would that difficulty be avoided by the use of an evaporator, which you spoke of yesterday, as needed to supply the waste of fresh water, by leaking around the boil- ers and engine ? A. That plan has been adopted in several cases, but has been abandoned for two causes : First, it was not found to be an absolute necessity ; secondly, that the use of an evaporator multiplies the amount of machinery, such; as cocks, pipes, and so on, to an extent that it is desirable to avoid, and, therefore, not considered as a profitable appendage to steamships. Q. (by Coroner.) Does not the indicator-card show the valve was open only five eighths of the opening when it was taken ? Is it not so written on the card ? # A. It is written Throttle 5, which is shown by the card to give an area equal to the opening through the steam- valves in the steam-chest. Q. (by Coroner.) Will not the engine work faster with wide- open throttle than five-eighths open ? A. That will depend upon the relative area between the main steam-valves and the throttle-valve. Q. (by Coroner.) The steam was at twenty-six and a half pounds at Governor's Island, and thirty-four and a half at the 98 Narrows — is it not certain that the boiler was making more steam than the engine was using ? A. Certainly; when the steam was at twenty-six and a half pounds, the engineer might have closed the throttle-valve, so as to allow the steam-pressure to reach the point he desired, which it would do in a very few minutes if the throttle was pretty well closed. Q. (by Coroner.) Was it not proper then, when the pressure had risen to the regulation amount, to open the engine, and so work it off ? A. After the steam had reached the desired point, the engi- neer would naturally regulate the opening of the throttle- valve to such a point as to maintain the desired steam pres- sure. Q. (by Coroner.) "Were there more braces put in the Meta- comet's boilers than were called for in the specifications, and if so, for what reasons ? A. I am unable to say ; they were not ordered to be put in to my knowledge. Q. (by Juror.) If the water in the boiler had been up to the rupture, and within seven inches of the furnace-room, and the great quantity of water overflowing immediately after the bursting, and from the active state of agitation of the steam and water, from its constant circulation, from the boiler to the engine, through the condenser, and returned back into the boiler, do you think it possible that superheated or explosive steam would be generated in that boiler ? A. I think not, from all the circumstances, that has been de- veloped in connection with case. Q. (by Juror.) Is not the steam during foaming really su- perheated saturated steam, and all the processes of drying steam in the boiler simply to bring the steam into its normal condition, that is, saturated steam, with its volume, density, and tension again ? A. All these contrivances are simply to bring steam into its natural- or normal condition. Q. (by Juror.) What in your opinion constitutes superheat- ed steam ? Can it exist to any extent in a boiler in contact with 99 the water, or must it be in a separate heating vessel for that purpose ? A. Superheaters are generally separate arrangements from the boiler proper, but it may be heated in the boiler. Q. Does the presence of superheated steam indicate itself by the pressure-gauges ? A. If you confine it, it will, because you increase its vol- ume, and therefore the pressure of superheated steam would indicate itself by a thermometer. Q. (by Coroner.) Is not the indication on the pressure-gauges the same as that of heated air, and not that of water ? A. If you confine it, it is. Q. (by Coroner.) Do not explosions mostly occur, in your judgment, from superheated steam? A. I think that is the case on the Mississippi Eiver, but is not the case when more skillful engineering is carried on. Q. (by Coroner.) Do you test those by a law of Congress, or by what law ? A. It is done in conformity with a clause in the contract and specifications requiring such test to be made in the Mercantile service — it is done by a law of Congress. Q. (by Juror.) Do you think boilers (the Monitor) are safer than the vertical or Martin boiler ? A. I do not. I think the Martin boiler as safe as any used in marine vessels, can be made as strong as any other form of boiler, and are equally as reliable. I have made the cruise of nearly three years, having four Martin boilers under my su- pervision during that time, and have never had occasion to find fault with them. I have no experience in the working of the Monitor or horizontal boiler. Q. (by Coroner.) Were not the boilers you referred to pro- vided with more steam-room than the boilers of the double- enders ? A. I should judge the ratio of steam-room to a cubical capa- city of the cylinders to be about the same in both cases. Q. ' (by Coroner.) Is the heating surface of these boilers larger than the boilers you refer to, larger in proportion to the steam-room ? w «< 100 A. I have never made any comparison or calculation on the subject, but I should think not. I think the Navy Department furnish the plans and draw- ings for the braces. Q. (by Juror.) Are . not the different boilers differently braced ? A. There are some variations in the different ships, made to suit the particular notions of the builders tending to furnish the necessary strength. In regard to boilers generally, I would as soon have charge of a set of Martin boilers as any other kind used in marine steamers. They give as little trouble as any boilers with which. I am acquainted, and I believe I have a pretty general knowledge of all kinds of boilers that are used in steam-vessels. The form of a boiler, so long as there is room to get in plenty of braces, does not necessarily prevent it from being a safe and strong boiler, and the type of boilers used in these double-enders is susceptible of being made as strong and as safe as any boilers now in existence, for if ne- cessary the brace rod could be run through every tube ; there- fore there is no reason why a boiler should not be strong. Q. (by Coroner.) After a boiler has been tested at sixty pounds hydraulic pressure, and found to stand the test, and is examined after the test, and no imperfections are found by that test, then run ninety-six hours with steam, at near its maximum allowance, and standing that steam pressure well, and after that explodes, at thirty-four and a half pounds steam pressure, how do you explain the explosion ? A. I do not consider the fact of a boiler withstanding suc- cessfully for a moment a hydrostatic pressure of sixty pounds is any evidence of a boiler being perfectly safe with a much less steam pressure as a working medium, for the following rea- sons ; in the first place, if all the braces are not equally tight, one must take more strain than another, at the same time be subjected to a greater strain than they were intended to bear; that is, those that were tighter than others ; in that case it would be very evident that more or less damage had been sus- tained by the braces that were too tight, and would be corre' spondingly weakened, and would be less able to withstand a less pressure in future, for any great length of time ; secondly, 101 when subjected to the hydrostatic pressures, all the braces and each one doing its proper proportion of the duty, between the time that the boiler was so tested, and the time of getting up steam for her trial, some of the brace-pins may have got out of their places, which is not an uncommon occurrence ; hence when subjected to a pressure again, although to a less degree, rupture may take place, owing to the absence or slackness in some of the brace-pins, bringing an undue strain upon which? in their proper position and condition beyond which they are able to sustain rupture, would be a very natural consequence under those circumstances. Q. (by Coroner.) Under those circumstances, would not the boiler be more likely to explode at her trial of ninety six hours, when she had forty on, than on her trip down the bay, with a pressure of thirty-four and a half pounds of steam ? A. It is possible, during the interim of the ninety -six hours' trial and the trip down the bay, that some changes may have taken place in the condition of the braces in the boilers. Some of them may have been removed for examination of the boiler, and other causes,, and may not have been properly replaced and adjusted. If the condition of the braces were known to have been the same during the trip down the bay, the rupture ought not to have taken place with a less pressure than that used at the trial of ninety -six hours, which pressure, if used at all, must have been for a very short time, as it was not authorized by the regulations governing the trial, nor was there any such pressure on the boilers when I visited her dur- ing said trial as General Inspector. Q. (by Coroner.) How. long a time were you present during the ninety -six hours' trial ? A. I think I must have spent about an hour. Q. (by Coroner.) Then that forty pounds pressure could have been on with your knowledge ? A. Yes, sir ; it could have been on with my knowledge. Q. (by Coroner.) When braces are removed for any purpose in boilers, is it not the duty of the workmen to replace them to the original point of location ? A. I would regard it as my duty to see them properly re- placed, and would do so. I would not even trust my first 102 assistant to do it. I regard such things of that importance that I should want to see for myself that the brace was properly replaced and secured. Q. (by Coroner.) Was not Mr. Oahill a careful man in that respect ? A. I have no knowledge of Mr. Cahill professionally. He was First Assistant Engineer in the service ; consequently could not have been as experienced as an engineer who had seen more years and more service. An engineer becomes compe- tent only by experience. A young man can not know as much as one who is many years his senior in age and experience. I speak in general terms. Q. (by Coroner.) Please say how much pressure was carried on the Eutaw. A. I can not say for»a certainty. George Sewell. Sworn to before me this 27th ) day of April, 1864. j Thomas P. Norms, Coroner. Edward M. DicJcerson, recalled. Q. (by Juror.) Will you give the relative value of two sets of boilers, the one the boiler now in the double-enders, and the other a set of boilers with vertical water-tubes, which might occupy the- same place in regard to safety, with cost and economical effect ? A. At the request of Mr. Montgomery, I have examined that question, and find that on the same floor-room, which is eighteen feet by thirty-two, occupied by the boilers of the double-enders, a set of vertical tubular boilers, properly ar- ranged by their inventor, Mr. Montgomery, could be placed, which would certainly give twice the steam from the same combustion which these give, which would be self-sustaining, which would be three feet lower than these are in time of ac- tion, which would cost less money to make, and not weigh more than their weight, and would not work water. Edward N. Dickersok Sworn to before me this 29th ) day of April, 1864. J Thomas P. Norris, Coroner. 103 James Montgomery, sworn. Q. (by Coroner.) Where do you reside ? A. Brooklyn at present. Q. (by Coroner.) What is your profession % A. I am an Engineer. Q. (by Coroner.) Have you formed any theory of this ex- plosion? A. I have. Q. (by Coroner.) Please state to the jury what that theory is. A. It is a theory based on an intimate knowledge of this pecu- liar water-tube boiler, derived from a knowledge of its elements extending over a period of over twenty-four years. In the columns of the American Nautical Magazine for the year of 1857 is entered up by me a protest, over the signature of a " Correspondent," ,, against these so-called Martin boilers, as arranged by this person, wherein I clearly pointed out the fact that these boilers were a malformation, both mechanically and chemically ; that is to say, the steam-boiler is a chemical cru- cible in all its essential particulars, in which many extraordinary combinations take place, all induced by the thermal effects of heat. In this connection, then, I declared in that journal that the cutting the furnace from the vertical side of the water-tube boiler, patented to me, its inventor, by the United States, Eng- lish, French, and Belgian Governments, that the transposition from the side, as stated, for the purpose of elevating the boiler about one third higher to make room for the same underneath and below the lowermost ends of the tubes, would be produc- tive of ruinous and dangerous consequences. As a consequence of this arrangement, the steam made on and around the furnace, amounting ordinarily to about forty per cent of the mass made in the boiler, must now necessarily, by this mal-arrangement, pass upward through the tubes at water ways, found in this class of boilers, thereby first checking what should be an unobstructed descending current unmixed with other than a very small per centage of steam ; whilst at the same time the principal volume would pass, as stated, through the tubes, thereby breaking what would otherwise be, under a proper ar- rangement, solid water. 104: Q. (by Coroner.) What would be the proper way to arrange, and how do you derive your knowledge of this boiler ? A. As the patentee and inventor of this boiler, I have stud- ied the thermal effects of heat on water in evaporating the same, and the -chemical combinations that result therefrom. In accordance, then, with well-known chemical laws, I arranged and combined the boiler patented to me as stated, and com- menced its introduction. The laws pertaining to this invention was found by me by various experimental trials requiring close study and observation. I discovered that great difficulty ex- isted in keeping the water in the water-tubes, of which the body of the boiler is made up. The water-tube boilers of Dr. Nott, ISTapen, Dondonald, and several others, were found inop- erative and abandoned by reason of the fact that the water was driven from the tubes, thereby causing their rapid destruction by burning out the same. A close observation by me enabled me to determine the chemistry of the day to be false, insomuch as that the Florence flask upon which Dr. Nott and others pre- dicated their'boilers, was only true under certain circumstances, as the following illustration will prove. The Florence flask is a simple bladder-shaped vessel with a long neck narrowing to a small orifice. This being placed on a metallic stand, and a lighted spirit-lamp placed under it for the purpose of evaporat- ing its contained water, will exhibit the simple and well-known phenomenon of the vivification of the water, in which the steam and water can be seen rapidly along the sides of the vessel, when the flame is hottest, liberating the steam at the surface, the water in the central part of the flask sinking downward by its gravity, making thereby the supply requisite to keep up the current of vivified matter at the sides. This is the theory upon which Dr. Nott predicates his boiler. This chemistry has been indorsed by the books from the earliest dawn of the science, but is only true, nevertheless, under the circumstances exhib- ited in the Florence flask, or some vessel of similar arrange- ment. As, for example, when in the case of the water-tube of Dr. Kott, a large number of tubes as stood in a vertical posi- tion, the same being from one to two inches in diameter, aver- aging about three feet long, with a furnace at their side, the tubes opening into water at the bottom and water at the top 105 end of the same ; the flame now being admitted to play around the tubes through spaces left between the same, acts to convert each particular tube to an evaporative or separate boiler. The effect of which is as follows : the steam made on the lower- most part of these tubes ascending upward, as in the case of the Florence flask, the currents ascending will cause the steam to become superheated as the surface over which it passes becomes hotter the higher the current ascends. This effect wiU be far greater on the front tubes than those remotest from the fire ; with a low draft it is possible to realize the effect pro- posed by Dr. Nott in accordance with the flask, namely : the water was supposed by the doctor to pass up the front tubes and down the back ones, as he supposed a sufficient difference of temperature would exist to cause the water to flow up the front and down the back tubes. Fires low enough to allow of . such circulation would not be sufficient to make the boiler prac- ticable and effective in use, as many experiments have proved with fires sufficiently strong to generate the steam in sufficient quantities for the engine. The whole mass or cross-section of water in the tubes at their upper ends was found to be expelled from the tubes, back and front alike ; thus falsifying the the- ory of the Florence flask in such a connection. Seeing this, I immediately came to the conclusion that water-ways placed at the sides of the tube-boxes would insure a rapid circulation up the tubes and down the water-ways, whereby the water might be kept in the 'tubes, rendering them for the first time effective and economical. I tried the experiment, and suc- ceeded in effecting this end. But still the boiler was far from being perfect, as I found the circulation still imperfect, though, by comparison, vastly superior to the boiler devoid of water- ways. I now added a simple device in the shape of a partition, calculated to divide the upper half of the tube from the lower. This I call a diaphragm. By then passing the heat above this diaphragm to the upper ends of the tubes toward the back of the boiler, causing it to dive at the extreme back end of the tube-box, and pass underneath and along the lowermost ends of the tube, I was enabled at last to prevent the tubes burning out, and generate the steam with great rapidity and an economy unknown previously to any kind of generator, avoiding by the 106 thorough circulation obtained by this combination, fully seven- ty-five per cent of the causes that produced incrustation from the salt and other impure water. When steam is superheated to the extent of even one degree above the pressure due to its temperature, a tendency to repulsion immediately commences. This it is which produces effervescence, the effect of which is, when strong and sudden, as will likely be the case in the im- properly arranged boiler on board the Chenango, be to cause the water to fume or rise upward in a solid body or nearly so, and so through the steam-pipes, a large surplus of which will pass overboard, thereby draining the boiler of what might be considered as its heart's blood, emptying it so rapidly that in one instance I Jcnew thirty inches of water taken from a boiler of this Mnd in less than one minute's time / so much water was withdrawn that no alternative was left but to draw the fires to save the boilers from destruction and those about them. This unfortunate effect was the result of practicing the same quack- ery practiced by Mr. Martin in the boilers of the Chenango aad others of the same class ; namely, the removal of the lower dia- phragm from interpose between the crown-sheet and the lower tube-sheet, known as the collecting and deflecting diaphragm. The name is derived from a two-fold purpose which it serves. On its lower side, as you will observe, it acts to deflect the steam made on the furnace upward by an independent channel entirely avoiding the tubes. This effectu'ally reduces by forty per cent the work required of the tubes in generating the steam, and restores the principle of the boiler to its purity as patented in 1845 ; at the same time avoiding the danger of scale and sedi- ments being thrown down upon the crown of the furnace below, as it acts as a collecting vessel to save the furnace from destruc- tion, leaving the current in the water-ways to pass downward unchecked by the passage of steam upward. With this light thrown upon this subject, together with the testimony already in court, and this piece of iron in my hand, I will now prove that this boiler exploded from d want of water on the heating surfaces. As practical engineers, every gentleman among you knows that these bolts could not be cut; in fact, partly sheared as these are, and bent with the quick curves with which they are bent, unless they were first heated to a very high temper- 107 1 ature, not less, in fact, than a cherry red. Observe their curves as well as the cuts. I now take this argument to be self-evident that I have advanced. What then becomes of the theory advanced by some'' gentlemen here on the stand, that the overheating of this boiler, as admitted by themselves, was due to the fires in the furnace at the time after the explosion f when, of course, trie heat acting upon the bolts and plates of which the boiler was made up, could exert no pressure in the absence of steam and water to partly shear and bend these bolts in this extraordinary manner, as in the ordinary or normal con- dition of the boiler a force of seventy-five tons would fail to bend these two five-eighth, bolts in the situation they occu- pied at the time of the explosion. This, then, is the theory which I have built up to account for this explosion, and after making a personal inspection of the boiler. Adjourned to Monday, three o'clock p.m. Monday, May 2, 1864. Mr. Montgomery continued : The pfoof that the boiler was in an overheated condition, even to the extent of over one thousand five hundred degrees Fahrenheit, is shown to have been the case by the preceding testimony, in which the stay- bolts holding the lugs to the tube-box were shown not only to be very much bent, but also partly cut in two, or sheared by the pressure drawing on them at the time of the explosion ; for of course it follows that after the explosion no pressure could have existed on either the boiler or its stays; as the enormous breach in the shell of the boiler had relieved the boiler of all pressure, except that of the air about it and in it. Therefore, no overheating of the boiler could have caused these bolts to bend upward, much less to be sheared upward in an upper direction, contrary to graving of the materials compos- ing the stays, and in the absence of all pressure as named. Q. (by Coroner.) Mr. Montgomery, I would ask you, for the benefit of the jury as well as my own, what opportunities you have had, if any, in verifying these theories ? Are they merely theoretical, or have you verified them practically? The jury, you must be aware, is made of practical boiler-maker3 and 108 engineers. State, then, what you know of boilers and explo- sions from your experience in practice and experiments. A. My experience and investigation has extended over a large part of the United States, North and South, England, and some little in France, where I resided some time, for the purpose in part of acquiring knowledge from the practical and theoretical engineers of these countries. My great aim was to acquire the proper knowledge of boilers, more especially with a view to their more economical working, and, above all, to render them entirely safe from explosion. That my labors have not been altogether lost, I propose to show by documents emanating from eminent men, well known, which I shall ap- pend to this testimony. Of my practical experiments I will now speak. I commenced my operations on the Mississippi River, and some of its tributaries. I purchased a portion of a high-pressure steamer, and became an oiler and fireman under my engineer. The information I there acquired enabled me to invent and perfect, and place on board of the United States steamer La Grec, the instrument whose entire success is demon- strated by the annexed document. [Document read, and an- anexed to the testimony, showing that he had devoted him- self to that branch of the science, " The Theory of Explosions."] The true theory of the explosion of steam-boilers may be readily understood by the simple explanation which I now proceed to make. Explosions are divided into two classes : the first, those that are entirely well-known and understood, which are fully and entirely under the control of proper inspection. The first is found in improperly formed boilers, such as are found in flat roofs, or nearly so, over-Sued — flues intended to be circular, but irregular in their formation — compound curves, such as are found in the abortions now used in the Navy, known as the Martin boiler. These forms are very hard to stay, and make safe against any other than very low-pressure steam. Second. The natural detonation by decay of boilers in use, and otherwise. It will readily be seen that these dif- ficulties are easily remedied by the inspector, by applying the hydrostatic pump, at proper intervals; these difficulties just named, and the manner of curing them, are, of course, univer- sally understood. I have now to answer my theory of explo- 109 sions, which I call the thermal theory, upon which my safety apparatus is grounded or based. All causes of explosions after those before named invariably proceed from an excess of temperature ; as, for example, if water becomes deficient in a boiler, from neglect to pump it in as it passes away by evapo- ration, the plates constituting the fire-surface become uncov- ered of water and exposed. Of course an excess of tempera- ture results, as they have been known to be heated even to a white heat. Should a vessel with common-roof boilers of any kind be much careened, from any cause, and remain so for a sufficient period, a portion of the flues in the boiler would be- come uncovered of water ; the flues would then be liable to collapse from the same cause — " over-heating. ," Third. Should scales, mud, or any foreign substance collect in the boiler, in' sufficient quantities to. form an incrustation, the water being cut off from the plate by a good conducting substance of which incrustations are made up, this also would cause the iron to burn, which would result in breaching the boiler in those parts where such incrustations had formed. Fourth. Boilers are sometimes improperly constructed with reference to the application of heat to the heating surface ; as, for example the bridge-wall erected at the back ends of .the grates, used on the Mississippi River, and elsewhere, are carried up very high, quite near the bottom of the boiler at that part. The effect of this is to choke and throttle the heat up in one spot, and that between the fire-brick wall, heated to the highest intensity, and the bottom of the boiler, as stated, producing thereby a con- centrated combustion, the effect of which is, to pour a flood of caloric through the iron w T ith such rapidity of conduction as to drive the water immediately over such bridge away from the plate, a phenomenon well known to boiler-chemists and experienced Mississippi engineers, and known among men of science as repulsion, produced, as already shown, from a con- centration of heat on one spot. Fifth. Steam, as it rises to pressure, rises by regular increments of temperature. With such exactitude does the temperature increase as the pressure rises, that a common thermometer was taken by me and altered by the addition of what I call a pressure-scale, in which two hundred and twelve degrees showed a pressure of steam of an 110 amount sufficient to balance the pressure of the atmosphere. From that it extended to ten atmospheres of steam, or one hundred and fifty pounds. This high pressure was indicated by three hundred and fifty-nine degrees of heat. It is now about twenty-two years since this instrument was arranged. Here, then, are proofs to show that an instrument properly based upon this thermal theory, apparent, doubtless, to the minds of the jury, would act, if properly predicated, to control effectually the steam of explosions. On learning these facts, I at once instituted a series of experiments which resulted in the production of a simple system of expanding bars of any good conducting metal, not calculated to oxidize or otherwise, for the galvanic action. This instrument I afterward applied, as the records show, to the United States steamer Le Ger, under the patronage of Eobert J. Walker, then Secretary of the Treasury of the United States, with entire success, as the docu- ments accompanying this show. A second apparatus was erected in New York City, as the accompanying documents also prove, highly successful, indorsed by Professor Ken wick, the author of the work known as Eenwick's Steam Engine. This, gentlemen, is the theory of explosions, which I have based upon simple theories with which you are all familiar. My knowledge of the proper manner of constructing boilers has been based upon sound and well-approved elements, which an experience of many years has entirely verified, and which the accompanying documents will indorse. Q. (by Coroner.) How does it happen that in view of these extraordinary facts, that you do not place them before the Government ? A. I have done so many times, but owing to the infamous machinations of corrupt officials, engineers, so called, who hap- pen to hold the office of Engineer-in-Chief, and their tools, I have so far, in spite of the patents that were issued to me as the original inventor of this boiler, been held by the throat by the strong arm of power, whilst quacks and other humbugs such as the Navy Department has abounded with for many years past, have wrested from me my property, causing me great anxiety, as well as loss, as I well knew from a personal knowledge of the men, their utter incapacity to embody the \ 111 invention in those proportions which true theory is always practical in imperatively demanding. The modus operandi of these robberies was as follows : Patents issued to me for this principle of water-tube boilers, having surrounding water- ways, with the furnace at the side of the water-tubes, has also a division-plate, known as a diaphragm. Two of my claims being withheld, they being five in number in all, I was in- formed by the office that if I could establish my right to the remaining two claims, in practice, by the actual success of the boiler, that the office would then, on my surrendering that patent, would re-issue me another with all the claims, five in number, called for by the first application. The boiler con- structed by me in New- York proved an entire success, being used for many years, evaporating fully twelve pounds of water to a pound of coal. Upon this I surrendered my patent. It was, after a severe contest, re-issued to me, with all the claims, covering that know as the Martin boiler. In spite, however, of this fact, and the existence of a book of drawings made by me to show a variety of type- of invention, at the instance of Mr. Martin and some of the naval engineers, letters were sent to the Commissioner of Patents, Judge Mason informing the Commissioner that this person had made »valuable improve- ments in boilers, which was of the utmost consequence, should be published to him as their inventor, more especially as he had promised the Government, in the event of such patents being issued, the use of the invention free of all charge, and filed a letter to this effect, as I am informed by people high in power and believe ; in short, this patent was merely to be is- sued to him merely to prevent any one else charging a patent fee, therefore including the right of the inventor. Upon this an application was made for a patent, omitting certain portions of the invention essential, and entirely so, to its safety, a por- tion, the omission of which has converted the most safe and economical boiler, as the record proves, into what can be called an infernal machine. Another patent issued to Mr. Martin, which I copied in all its essential particulars, and demanded a patent for, as the original inventor, after a contest of about three years, involving the expenditure of a very large sum of money and the ruin of my business. In the mean time, a pa- 112 tent issued to me through Judge Holt, then Commissioner of Patents, in which both he and a leading member of the Board of Examiners, who adjudicated this matter, declared the thing to be a great wrong, and regretted the impossibility of annul- ling the patent, but stated that the issuing of a patent over that granted to Martin was a virtual annulment, and that any court in the country would give me my rights. Upon this, I addressed a letter to Secretary Welles, asking that he, as a lawyer, would examine the record and ascertain whether these boilers were mine or Mr. Martin's, as also certain prior corre- spondence, in which these boilers were denounced as unfit in the arrangement made by Mr. Martin ; asking him also if the property was found to belong to me, that he would order the man who had invented and patented the invention to be sus- tained in his constitutional rights in accordance with the laws of patents, and farther, be kind enough to answer the com- munication sent. He responded by the letter read, stating that my letter must be addressed to contractors, as they had the Government fees. [Letter annexed.] Upon this I in- stituted inquiries into the matter, and was astounded by dis- covering that a printed document circulated among the build- ers and others, notified builders that all patent fees must be assumed by them. Further on, however, in the same docu- ment, they were substantially ordered to pay Mr. Martin, in utter defiance of my rights, although each individual knew the invention to be mine. This, however, was necessary to secure -contracts from the Government. The omission by them of that part of the invention known as the diaphragm, as also a second diaphragm known as the collecting and deflecting dia- phragm, has acted to produce this and other like tragedies, and will continue to do, as long as these boilers may be continued in use in their present lame and dangerous condition, as will be clearly shown to the minds of all by examining carefully the principles fully and properly eliminated in my specifications descriptive of this patented boiler. All the within papers are submitted and annexed, for the purpose of the elucidation of the same. Of the Secretary of the Navy, Hon. Gideon Welles, I would exonerate, as far as in me lies, from all implication of knowingly furthering this wrong, or abetting it at any time, as 113 my previous experience with the Department has taught me from information derived directly from various Secretaries of several Administrations, the Engineers-in-Chief, to slaughter alike boilers, engines, and machinery of all kinds at their several will and pleasure. James Montgomery. Sworn to before me this 2d ) day of May, 1864. J Thomas P. Norms, Coroner. W. A. Zighthall, sworn, says : I reside near Jamaica. I am an engineer. I have formed no theory of this explosion only from what I have heard. My theory of explosion and ruptures of boilers are divided into three parts : Bursting of boilers does not often occur, and very rare. Euptures of boilers are merely the protrusions the boiler will make in blow- ing out of a brace, or breaking of the braces. Boilers bursting with plenty of water in them is of very rare occurrence. I consider it a very hard matter to burst a boiler, with proper care. I have tried steam myself on boilers to very great ex- tremes. I have seen the seams, rivets, and sockets sweat at every pore. But with a safety-valve properly loaded, there is safety on board a steam-vessel, or there would be no safety go- ing on board of them. The explosion of boilers is a different thing entirely, and when a boiler is fitted for an explosion, safety-valves in numbers would be of no account. My opinion of the explosion is in this, as in all cases, is that men are de- ceived in regard to the state of their boilers. I have stood hours and hours at my boiler, not trusting to any other man. I followed the business on the Hudson Biver for twenty-five years, and never met with an accident ; and do believe that I do understand the nature of water in the boiler, and I also be. lieve that all boilers will foam at times. Boilers built with, out proper steam-room are more liable to act in that way. I have seen a boiler burst from a pressure not exceeding thirty pounds, and was on board of the vessel, giving out in the weakest part. I do not believe that any boiler can burst, with proper care. If it was not so, it would not be safe to travel on steam-vessels. 114 Q. (by Coroner.) If this boiler stood a test of sixty pounds of cold-water pressure, and was afterward found perfect in all its parts, then run ninety-six hours at the dock as high as forty pounds of steam, and afterward exploded at a pressure of thirty-four and a half pounds, to what would you attribute the explosion ? A. I would call that an explosion. My reasons are these : 1st. That the boiler was tested at a hydrostatic pressure of sixty pounds; it has always been thought that sixty pounds cold-water pressure would hold thirty-five steam pressure, but the Government test their own boilers. 2d. My view is that when water foams so excessively, there is always danger, and it always wants watching. All new boilers will foam more or less. I would think any man should know where the water is under all circumstances. Whenever I was doubtful of the con- dition of the water, I would shut the throttle and open my fur- nace-doors. I do not think without one of these movements that a man could tell where the water is in his boilers. Q. (by a Juror.) Don't you think it would be possible, by running the water-pipe connected with the water-gauge, down to the bottom of the boiler, as shown in the drawing presented, for a man to tell where the water in the boiler was, with the steam-pipe running two feet above the water-line? A I answer, most emphatically, no, sir. The water is solid under the bottom of the furnaces where the fire does not come in contact. The pipe, as shown in the drawing, at the bottom is correct, but I do not think the pipe high enough to indicate solid water, from the drawing shown, whilst in a state of foam- ing. In all hollers where the steam-room is contracted, they are more apt to throw off the water from the holler. I have seen several of the double-enders. I don't see why they should not be as safe as other ships, with their boilers properly braced. Q. (by Coroner.) Will any amount of bracing prevent an ex- plosion, where the conditions of an explosion exist ? A. Bracing will not prevent the explosion, If the condi- tions exist In the holler — the more strongly they are hraced, the greater will he the damage. In my opinion, the Che- nango holler exploded from the want of water, and a sudden Irritation of the ivater. I have known a boiler to explode by 115 merely moving a cock to displace the steam. I have known two boilers on the Hudson River to explode for the want of water, and I do not believe that many accidents happen, except through that cause. No safey-valve is a guard against an explo- sion. There is superheated steam in all our boilers. When you have plenty of water in the boiler, superheated steam is harmless, but when at low water it is very dangerous. Low Water is the cause of all the explosions in the country. I account for this explosion by superheated steam in the boiler , and heated surfaces of the boiler. I never examined the boiler of the Che- nango ; know nothing about them in any particular. If the pressure on the safety-valve was greater than the boiler could stand, it would of course explode. Q. (by Juror.) Is not the glass gauge outside the boiler, and the water in that gauge, not subject to be disturbed in a great degree by foaming? A. Water in all glass gauges is more or less disturbed, but much more when they have not very high steam-chimneys. Q. (by Juror.) Would not the foaming affect the glass gauge in a boiler with a high steam-chimney, as much.as it would in a low one? A. No, sir. Q. (by Juror.) Is the steam entrance to the glass gauge attached to the chimney, or the side of the boiler ? A. They are attached to the side of the boiler, and run up to the top of the steam- chimney. Q. (by Juror.) Is the giving way of the boiler by over- loading a safety-valve an explosion, or does it operate like an explosion ? A. They are as much unlike as possible; when a bursting of a boiler takes place, and finds an exit in the weakest point, but when an explosion takes place, it has no reference to any particular parts; all goes alike; safety-valves are of no ac- count. Q. (by Juror.) Do you not think there are many circum- stances, such as imperfectly staying, etc., that would cause a boiler to burst under a less pressure than it was tested at ? A. My judgment is, that no boiler can burst under a much less pressure than its test ; if so, there is no use in going to the trouble of testing boilers. 116 Q. (by Juror.) Do you think the accident on board of the Chenango would have been likely to happen, if proper care had been taken on the part of the engineer who bad charge ? A. I do not think that such an accident could happen to any one who would take the proper care of a set of boilers, no matter how bad they were. It is the duty of the engineer to take care of his boilers ; his engines will take care of them- selves. Q. (by Coroner.) Supposing the glass gauge on the boiler indicated two and a half cocks of water, and she had a pressure of thirty-four and a half pounds of steam, as shown by the in- dicator diagram, what means had the engineer of knowing that he was in danger ? A. To open the fire-doors first, then shut the engines close, and if not quite satisfied, to stop them, and if he found the water low, to raise the safety-valve, to cause the same flow of steam from the boiler, until it all blew off. The water in the water-gauge is not an infallible test when the boiler is foam- ing. It takes a good head and ear to tell when the boiler is in a s^ite of foaming. Q. (by Coroner.) Is not the resort to opening the furnace- doors, stopping the engine, cooling the fires, one that an ordi- nary engineer would hesitate about before doing it ? A. No, sir, not if the man attends to his business. He will never hesitate; he will slow his engine, or do something to show where the water is in the boiler. I would account for the burnt appearance of the felt and melted lead shown, by saying, that lead never melts except at about six hundred degrees of heat. Felting never burns without excessive heat. Super- heated steam will burn the jackets off steam-chimneys every year, while the jacket on the boiler will last until it wears out. I think the piece shown was melted by superheated steam. I have seen it done; have done it myself ; but pure ordinary steam generated from water will never harm any lead-joints, or burn any felting. I have never known it in my experience. % Wm. A. Lighthall. Sworn to before me this 2d day of May, 1864. Thomas P. JSTokkis, Coroner. 117 Daniel B. Martin recalled. Q. (by Coroner.) In the course of Mr. Dickerson's testimony he alluded to testimony given by you in the case of an explo- sion in Bridgeport — will you explain the matter ? A. This case is entirely dissimilar, that being what is called an upright boiler of some forty odd inches diameter, with one cross flue, and two or three upright connections from the fur- nace to this cross flue. This boiler was attended by a boy with but a few months' experience, who left the boiler at about ten minutes past twelve, and went to his dinner ; on his return, a few minutes before one o'clock, the boiler exploded. After standing some thirty or forty minutes, the supposition then was, that this lad had been deceived in the height of the water in the boiler, and leaving the boiler with a large fire in, that the steam during this length of time became heavily sur- charged, lifted the safety-valve, and by that means caused the explosion. The dissimilarity in the two cases was, that one stood a long time with water quiescent, giving the steam a fair opportunity, whilst in the other the engine kept constantly going, taking its supply of steam from the boiler. The steam consequently had not the time to become surcharged, in case the water had been low. Q. (by Coroner.) Did not one of these double-ender boilers, just like that of the Chenango, recently explode when being tried at Newburgb, killing several persons? A. Yes, sir. I have the report of that case. They com- menced to fire up on the boiler, to test it with steam, very early in the morning. About ten o'clock they commenced to make steam, feeding with wood about eleven a.m. They had steam to fifty-four pounds, by the pressure-gauge, and a full fire in. An order was then given to the two men who were firing on the boiler to draw the fires by the master boiler- maker. The master boiler-maker then returned to the shop. The men, instead of hauling the fires as they were told, w r ent up in the yard and returned in twenty minutes, and com- menced to haul the fires, when this explosion took place. There was no safety-valve on the boiler, nor any means of letting off the steam or admitting water, except by a cock on the top 118 of the boiler, that had been used for filling and testing it. The pressure that it gave way at was unknown to every body, ex- cept those that were killed. - Q. (by Coroner.) Was it possible that the engineers on board of the Chenango could be deceived as to the exact con- dition of the water, as indicated by the water-gauge ? A. I think not, sir. This gauge I consider the most perfect test of any thing that has ever been gotten up, for the reason, as has been testified by Mr. Dickerson here on the stand, that this engine took its steam eighteen inches above the water-line, which would be twenty-four inches above the tube-sheet, and the steam connection of this gauge was three feet nine inches above that point ; consequently there was nothing to draw the foaming water up to that point. In case the water did reach that point, the steam or dry-pipe would be submerged in nearly solid water. In that case the cylinders would be filled with water to the point of cutting off. This gauge has another safety-guard against the indications of water foaming over, by the glass gauge being connected to a chamber on one side of the main channel of water. This gauge stands in plain sight of a man in the engine-room taking diagrams. Q. (by Coroner.) How do you explain the fact of the mer- cury being blown out of the gauge ? A. I am under the impression that the mercury-gauge was not blown out. Q. (by Coroner.) What gives you that impression ? A. Practical experience shows that from two to three inches of the mercury should be worked out by mechanical means. The means used generally is to blow it out by putting the mouth to the gauge. The reason of this is, that the sudden opening of the lower cock of the gauge, relieving the mercury of its steam pressure, allows the mercury to come back with such a momentum, that a portion of it will pass out of the short lug and become wasted. In regard to the water found in the long lug of the gauge, I have found gauges in that way in my experience, and that I have no recollection of ever taking down a gauge that is placed below the decks of a vessel, that I did not find water, or evidences of its having been there, 119 which evidence would be in finding the oxide of iron on the top of the mercury. I never could account for how this moisture got there, unless it was by what we term the sweating of the metal, or what is more properly called the condensing of the atmosphere in the gauge — as it is a very ordinary thing to see the water, in damp weather, running off the metallic parts of the machinery below decks. This gauge of the Che- nango sets under the hatch, where the storms might beat into the top of it, and water get in in that way. It also is under the crank-pin, in one position of the engine, where, if water had been used on the crank-pin, it would be likely to get into it. Q. (by Coroner.) It has been testified here, by the engineer who ran the engine on her trial, as well as others who ran the Pawtuxet and Metacomet, that this boiler worked water badly. How do you account for' that ? A. I believe it has been testified here that the water worked through from the boiler to the engine, through the cylinder, from the cylinder to the condenser, so through that to the fire- pump ; the residue that the pump could not take, worked over- board. I wish to say that such a thing can not be, for these reasons : In case the water comes through, as represented, it must come through before the exhaust-valve is closed ; and then, as this valve closes four inches from the end of the slope, which closes that communication from that to the end of the slope, the water must be forced through the steam-valves, or through the relief- valves, or the head of the cylinder must burst, or the piston breaks; and as no evidence has been given here, that I have heard, of the steam-valves lifting, for the water to return back to the steam-pipe, or that the relief- valves would open themselves, is proof that no water returned back through the exhaust, except what went in the form of steam. As some witness has testified that one thousand six hundred and thirty-nine pounds of water passed through the cylinder at each revolution, I hereby hand in the paper marked 249, showing a contradiction of that statement, and this will show that the whole amount of water would have been emptied out of the boiler into the engine-room in two and a half minutes : 120 Water in Boilers of IT. S. Steamer Otsego. In one boiler. In two boilers. Water to tops of furnaces, 184.64 cub. ft.=ll,447 lbs.X2 = 22,894 lbs. " lower tube-sheet, 308.68 " =19,138 " X2 = 38,276 " " upper tube-sheet, 456.75 " =28,318 •" X2 = 56,636 " " six inches above tube-sheet, 548.47 " =33,005 " X2 = 66,010 " Number of revolutions of Engine required to empty the Boilers at the rate of one thousand six hundred and thirty-nine pounds of water per stroke. From six inches above tube-sheet down to upper tube-sheet, 7 revolutions. " upper tube-sheet down to lower tube-sheet, 11 " 18 " lower tube-sheet to top of furnaces, 9 " 27 " top of furnaces to bottom of boilers, 14 " 41 Number of revolutions required to empty boilers completely, 41 Q. (by Coroner.) How can you account for the boiler ex- ploding at a less pressure than that tested at with cold water ? Can you give any other reason than you have already given ? A. I can. It has been testified to here, that the boiler had been examined after the test. This examination could not be properly made without the removal of some of the stays. These stays having been originally fitted each one to its place, to take its proper strain, and as there may be inequality in the length of the braces, these braces, in putting them back, may have become changed. As the pins are the last things put in; the person putting them in, finding them loose, may drive them home, thereby springing down the crown, so much so as to start the adjoining braces, and probably bring the strain from two to three to one brace. Q. (by Coroner.) Suppose, then, that the braces had been re- moved and readjusted — and then the boiler stood a pressure of forty pounds of steam for ninety-six hours — how do you ac- count for the explosion at thirty-four and a half? A. It is possible that the indicator-card might have been taken some minutes before the explosion, and perhaps some of the braces might have been changed while the boat was at the Navy Yard. Q. (by Coroner.) Mr. Mason swore that the self-acting relief- valve, from the fresh- water end of the air-pump, at times de- livered a solid column of water overboard, while at times an 121 hour would elapse without any water going over. Where did the water come from, except from the boiler ? A. If the check-valves on the boilers were screwed down, it would have to take that course — there was no other way for it to go. Q. (by Juror.) The boilers having been made with thirty - two stays, would it not have imparted double the strength as to its tension, and doubled the chances against the damage of bursting, if there had been, as in the drawing, sixty -four stays, and which the inspector testified there should have been ? A. It would have been double, minus the strength of the crown with its T iron braces. Q. Does the duty of the inspector merely extend to a proof- test of the boiler, or was it not his duty to report to his su- periors such a very serious change in their construction, as re- ducing the stays (if they were reduced, to half the number ? A. It was the duty of the inspecting engineer to notify the contractor, if the contractor still persisted, and then to notify the Department. Q. (by Juror.) At the Morgan Iron Works the piston was driven on the rod. How could this be, when the drawing shows a collar on the rod ? A. If the rod was fitted properly it could not be done with- out crushing the metal. Q. (by Coroner.) How do you account for the melted lead ? \ A. I can not account for the melted lead. Daniel B. Martin. Sworn to before me this ) 2d day of May, 1864, J Thomas P. Norris, Coroner. 122 CHARGE BY CORONER KORBIS TO THE JURY. Gentlemen of the Jury : The law has imposed upon us the duty of investigating the causes which produced the death of twenty-eight of our fellow-citizens, who were hurried into eternity without warning, and suffering from tortures which appalled us all, whose painful duty it was to witness them. In the enjoyment of health, elated with the prospect of an honorable service in the cause of their country, these unfortu- nate victims of some most shameful incapacity were suddenly destroyed ; not by the hand of the enemy, but by causes which they had a right to expect could not occur on a man-of-war, built by the Government without limitation of expense, and managed by a large number of persons, whose sole duty it was to guard against any accident which human skill could avert. As the cause of this terrible calamity might, upon one view of the case, be inherent in the organization of the ma- chinery itself, and therefore would exist in a great number of other vessels belonging to the United States just like the Che- nango ; and as an investigation into that cause must of neces- sity require the knowledge of scientific men, I thought it my duty to ask the aid of engineers of well-known ability to ex- amine the boiler, and to give us the benefit of their knowledge andopinion; and you have heard the testimony of some of them. The facts which have been proved before us, without dispute or contradiction, are as follows : The Navy Department of the United States, requiring some thirty side-wheel light draft gunboats, prepared the plans for the engines and boilers of these vessels, and called upon contractors to build their ma- chinery according to those plans, under the superintendence of the United States engineers. Among others, Mr. Quintard undertook to build two sets of these engines and boilers, of which the machinery of the Chenango was one. The material out of which these boilers were made was ordered according to specification ; and the evidence of the gentlemen who fur- 123 nished the iron, as well as of those who have tested samples of it since the explosion of it, shows, without contradiction, that it was of the best quality. The boilers were tested, ac- cording to contract, v/ith a cold-water pressure, and endured sixty to sixty-five pounds to the square inch without yielding. The braces were then examined, and found to be perfect ; and the boilers were accepted by the United States Inspector as satisfactory and according to contract. The engine was then run for ninety -six^hours at the dock, in order to comply with the contract, and the whole machine was accepted by the Gov- ernment and delivered out of the hands of the contractor. The ship then went into commission, and was proceeding to sea on her first voyage, in the charge of a young man by the name of Cahill, a Second Assistant Engineer in the United States Navy, acting as Chief Engineer on this occasion. The vessel proceeded down the bay, and when below Governor's Island, Captain Fillebrown visited the engine-room, and found twenty-six and a half pounds pressure of steam on the boilers as indicated on the gauge. Mr. Cahill then told the Captain that the fires were burning well and that there was no need to use the blowers. The Captain went on deck and did not re- turn to the engine-room until the vessel was in the Narrows, when he again went below. Up to this time the speed of the vessel was between eight and nine knots an hour. The Cap- tain had a conversation with Mr. Cahill at the end of the cyl- inder — a long distance from the boilers — and Mr. Cahill told him that the engine was running well. The Captain then said that the vessel had about eleven miles more to go, and he went on deck, leaving Mr. Cahill by his desk at the cylinder end of the engine; and as he stepped on deck the boiler ex- ploded, scalding thirty-two men, of whom twenty-eight have since died from the effects of the injuries then received. The question now before us is, what was the cause of the rupture? It appears that boilers are ruptured from two causes — one of which is the gradual accumulation of pressure, until the resist- ing power of the boiler is overcome in its weakest part and gives way, which is called a " burst " or "bursting ;" and the other is the instantaneous generation of an enormous pressure on the boiler, from causes which attend low water, and which 124 is called an "explosion." The first branch of the inquiry is, whether the boiler burst from weakness of material, or a de- fect in its construction, when canning the pressure of steam which it was intended to bear. We have the means of know- ing exactly how much pressure was on the boilers immediate- ly before the explosion. The pressure was thirty -four and a half pounds to the inch, as shown by the indicator-card in- dorsed by Mr. Cahill himself; so that it is made certain that if the boiler did burst from weakness, it yielded to a pressure a little more than one half it had endured from the hydraulic press, and five pounds less than it had borne from steam when running at the dock for ninety-six hours, and when forty pounds to the inch had been carried. It is also proved by Mr. De Luce, the Chief Engineer of the Navy Yard, that lie measured the safety-valve immediately after the accident, and found that it would blow off steam at thirty-nine and a half pounds ; so that the boiler was protected by that means against the possibility of a steam pressure equal to that which already had been used with safety. The question is, then, whether it is possible for a boiler to burst under a pres- sure of steam to-day, five pounds less than it endured under steam yesterday, and twenty -five pounds less than it endured from cold water last week? On this subject we have the opinion of Mr. Maxon, the United States boiler-maker, who swore that he would consider the boiler perfectly safe to carry forty pounds after it had been tested at sixty pounds of cold water ; and it appears that the statute law, under which all passenger-steamers are run, permits the boiler to carry forty- five pounds to the inch after a cold-water pressure of sixty ; and that the experience of many years has shown it to be per- fectly safe. On the contrary, Mr. De Luce and Mr. Sewell, United States Engineers, and Mr. Eowland, express the opinion that a boiler is quite likely to burst under a much less pressure than it had been tested with cold water ; and Mr. Eowland fixed the amount as low as fifteen pounds to the inch, in this case ; and these witnesses are of opinion that this cold- water test is of no practical value. It is not suggested that there is any other means known of insuring the safety of the boiler except this cold-water test, and if these isolated opin- 125 ions, unsupported by any instance of the kind, are well found- ed, it is obvious that no one can be properly charged with the consequences of an explosion, since no human skill can make sure in advance that the required strength existed ; and it is equally obvious that all the thousands of boilers now running, and relying upon the safety of this test, are instruments of de- struction, acting upon some capricious impulse impossible to be foreseen, and likely to scatter death around them at any moment. Fortunately, however, experience proves that boil- ers so tested are safe against any less pressure. ~No witness has denied that this boiler was tested to sixty pounds ; no witness has said that it was not strong enough to bear sixty pounds when built and delivered ; and the only suggestion which has been made (and this is m&ely a suggestion) is, either that some of the braces had been removed by the engineers and not replaced, whereby the strength was diminished, or that in testing, the braces might have been reduced in strength, so as to burst at thirty-five or forty-five pounds to the inch. The first suggestion is met by the proof that all the braces were in place, and are actually carried away by the explosion, and the second one by the proof that after the test the braces were ex- amined and found all right, and conclusively by the proof that forty pounds of steam was carried on the boiler after this test, which was much more than the pressure immediately before the explosion. You are therefore left without any proof, either deduced from the well-known calculations based on the ascertained strength of iron or from any experience in regard to the testing of boilers, from which to infer that the boiler did burst at the low pressure of steam which was being carried. You will then consider whether the boiler was burst by gradu- ally accumulating upon it a pressure greater than it had shown itself capable of bearing ; or whether it was exploded by those causes which do constantly produce explosions in boilers, and which, when they are called into action, overcome all resist- ance and devastate in proportion to the strength of the boiler, which has in vain struggled to restrain their destructive force. It is not a part of our duty to speculate upon the best way of bracing or securing boilers, if we find no proof that the brac- ing in this particular case was too weak to endure the load it 126 was designed to bear. The evidence shows that a great variety of opinions upon the best methods of bracing exist among men equally experienced in the business ; and, as there is no standard fixed by law or universal custom, it must at last come back to the simple question in each case, whether the method of bracing used in that case was sufficient for the purpose intended ; and if it be sufficient, it is of no consequence that some other con- structor would have used some other method. No boiler would probably ever be built if the different views of all men about the best way of constructing it had first to be reconciled. The specifications under which these boilers were built partic- ularly provide for the manner in which their braces shall be secured to the roof of the boilers, but it leaves to the superin- tendence and control of th# United States engineer in charge and the discretion of the boiler-maker how they shall be secured at their lower ends — subject, however, to the condition that they shall be able to stand a water-pressure of sixty pounds. In this case it appears that the specification is complied with so far as it prescribes the exact number of points of support overhead, and that the manner of securing the lower ends of the braces was the same as had been used on about eighteen others of these boilers with entire success, and such as was approved by the United States Inspector and accepted by the department, and that it was sufficient to endure the test required by the contract. It is proved that more braces could have been put in, and that the boiler could have been made to endure two or three hundred pounds to the inch, if such had been the requisi- tion of the specification ; but if it had been the calamity now so dreadful would have been intensified in horror, and we should probably have bad no one living to tell the tale ; for when explosions do occur their destructive force is in propor- tion to the strength of the boiler, which restrained the pressure until it accumulated to the bursting point. In the absence, then, of any evidence that the boiler was too weak to bear the pressure it was designed to carry, you will next inquire whether the pressure was gradually accumulated upon it above what it was able to endure. The testimony is conclusive on this point. There certainly was not more than thirty-five pounds of pres- sure immediately before the explosion, as proved by the indi- 127 cation diagram ; and if there had been thirty-nine and a half the safety-valve would have blown off the steam. Pressure rises very slowly when an engine is running, and in the short time between Governor's Island and the Narrows, with the en- gine working, it woulcl seem impossible that a bursting pres- sure could have been raised from twenty-six and a half pounds of steam ; and if it were possible it would warn every one, first by the gauge; secondly, by blowing off at the safety-valve below forty pounds ; and thirdly, by blowing out the mercury-gauge at about fifty pounds, none of which events occurred. You are then brought to the only other explanation, and that is, that the boiler exploded in the usual way in which such accidents do occur, and in consequence of low water. I don't propose to recapitulate the scientific testimony which you have heard in regard to the precise manner in which low water does lead to an explosion. It is conceded by all that when the water is low in a boiler a great intensity of heat is accumulated in the steam which has been brought in contact with metallic surfaces highly heated, and that in that state it is called superheated steam, and is extremely dangerous, and that such a condition of the water and steam is always found to accompany an ex- plosion. It is enough for us to know that low water will pro- duce an explosion, even though science may not be able to trace with entire certainty every step of the process by which the result is produced. The circumstances which attend an ex- plosion are an instantaneous and irresistible development of steam, which produces its effects " as if by the explosion of gunpowder," to use the language of the distinguished Tyndail, and does its work of destruction before its victims have time to escape, leaving its traces in the terrific energy with which it has torn apart the ties of iron which, upon all known calcula- tion, were capable of bearing many times the strain that ordi- nary quantities of steam could impose upon them. Do we find these circumstances here ? The boiler exploded within ten seconds after Captain Fillebrown and the Chief Engineer stood by the gauge at the end of the cylinder, not noticing any un- usual pressure, and when the very moderate speed of the vessel (between eight and nine knots an hour) gave evidence of a very small amount of power in action upon the engine itself. The 128 blowers were not running on the fires, and the Chief Engineer, who was in a position where he could not observe the indica- tions of the water-gauge on the boilers, said that the engine was working very well. Up to this time the engine had been run partly throttled off, and the steam, which was at twenty-six and a half pounds pressure at Governor's Island, had run up to thir- ty-four and a half at the Narrows. Under these circumstances, it is admitted by Mr. Sewell, the United States Engineer, and otherwise proved, that the engineer must have done one of three things — either allowed the pressure to exceed the limit allowed, or opened the furnace-doors, or opened the throttle- valve so as to still further increase speed, and that he did would seem to be free from doubt in the nature of things. The evi- dence is, and it seems to be a matter of common knowledge, that explosions from low water occur when the throttle-valve is opened, so as to increase the demand for steam upon the boiler, and so far at least to diminish the pressure, and, apparently, the chances of an explosion ; and all agree that under these circumstances the water which yet remains in the boilers rises into the superheated atmosphere above it, and is thrown upon the heated plates, which either by the direct action of the fire, or by deriving their heat from the superheated steam itself, have acquired an excess of temperature above that which satu- rated steam itself possesses, and which are therefore able to yield some of their surplus heat to the finely divided water which rises in the shape of foam. As is usual in the case of explosions, the men who either innocently or carelessly pro- duce them no longer bear witness on earth, and we must infer their probable conduct from the circumstances in which they were known to be placed, and the inducements which operated upon them. In this case the engine had been shut off to a cer- tain extent in order to gain steam, and of course Mr. Cahill could have had no other object in accumulating pressure, ex- cept to use it when accumulated, and so to find out the capa- city of his engine when its powers were to be tested for the first time. In opening the valve, if he did it, Mr. Cahill would have been diminishing the pressure on his boilers, and if the water had been at its proper height the operation would have been entirely safe. He himself did not know where the water 129 was in the boilers, as he had been conversing with the captain for some time, and as it appears, taking indicator-cards from the engine at a place where he could not possibly have known the condition of the water in the boilers, as Mr. Lawton has told us ; and he had a right, perhaps, to infer that the boilers were as they should be, and more particularly so, as it seems that he had not seen them operate on the trial at the dock, and might not have known their tendency to throw out their water with great rapidity. This brings us to the consideration of the probability that the water was low in the boilers. There has been no witness before us qualified, from his own knowledge, to give any testimony as to the exact condition of the water- gauges at the time of the accident, and we must look to circum- stantial evidence in this regard also. Of that we are furnished with a great abundance and of a most conclusive character. This boiler and engine were used at the dock for ninety-six hours, during which time the most extraordinary results were exhibited. The water worked out of the boilers into the en- gine, and so overboard, so freely that sometimes over a third of the cylinder would be filled with water, and the momentum of the machine would be suddenly arrested, as is proved by Mr. Mason, who had charge of the trial. On one occasion the quantity which suddenly came over from the boiler to the cylinder was so great that the piston was driven up the piston- rod about the sixteenth of an inch by compressing the water between the cylinder-head and the piston, as proved by Mr. Kiggin, who assisted on the trial. The danger of an explosion from low water at the dock was so great that the last witness refused to open the throttle- valve, when requested to do so by the United States Engineers on board, who represented that the contract required the engine to be run wide open. The witness said that he considered his own safety endangered, and should act on his own judgment. Mr. Bell, who took indicator diagrams at times during the trial, from the engine, says that the water worked out of the boilers so as to be heard striking in the cylinder frequently, when he was on board. Although the engines are arranged with a fresh water or " surface con- denser," whose office it is to keep the boilers supplied with fresh water, the water became salt very soon, and had to be 9 130 blown out, as if the engine had no " surface condenser." This was the condition of the Chenango when she was delivered into the charge of a second assistant engineer, with assistants, who, it appears, had not witnessed these operations in order to go to sea on duty. There is no difference of opinion among the en- gineers who have been examined on the subject, that a boiler in that condition was unsafe, and required extraordinary skill to avert an accident ; and the question is whether that extra- ordinary skill was employed upon them. The young men in charge are not pretended to have possessed any thing more than ordinary skill in their business, as their rank shows. In addition to these probabilities thus established, there are other facts which can not be denied or deceive others in regard to this matter. The mercury -gauge which was fitted and adjusted with the tell-tale set at zero, and from which no mercury could be expelled until the pressure exceeded forty-eight pounds to the square inch, was found by Mr. Powers, the boiler inspector of the City of Brooklyn, and by Mr. Dickerson, the witnesses who examined it in the presence of the jury, to have lost about five inches of mercury, so that the tell-tale stood about two and a half inches above the zero on the scale ; while at the same time the water which is generally in the small pipe connecting the gauge with the boiler, had been all blown out, and was found at the atmospheric end of the mercury and in the tube above it. There is no way in which this mercury could have been expelled from this tube unless by a pressure of steam more than forty-eight pounds high ; unless between the "time of the explosion and the time of the examination in our pres- ence this gauge had been taken down, some of the mercury poured out, and some dirty water poured into it ; which possi- bility is negatived by the testimony of Mr. Sullivan, who swore that nothing had been touched until it was examined in our presence. The hair felt which covered the top of the boiler where it was ruptured was found burnt black and shriveled by excessive heat, a sample of which is produced before us, while the wood in immediate contact with it shows no scorch- ing, and the witness told us that steam which is superheated by contact with hot iron will shrivel up animal fibers, like hair or leather, while it would not yet be hot enough to set fire to 131 wood ; but that saturated steam, or steam no hotter than water out of which it is made, would only be two hundred and eighty- nine degrees Fahrenheit hot at the pressure of forty pounds, and therefore not hot enough to burn hair. This is said to prove to a demonstration that the steam must have been super- heated to a high degree ; and it is admitted that unless the water was low no such effect could have been produced. It is also in evidence before you that the lead covering which was laid upon the outside of the boiler and outside of the felt was melted by the heat of the steam, and specimens have been shown you which were taken from the sheet lead immediately at the edge of the rupture, and which bear evidence of hav- ing been subjected to a melting heat. Steam at six hundred Fahrenheit will melt lead, and it is said by witnesses that it is common in cases of explosions, and in cases where low water has not been followed by explosion, to find lead and solder melted by the hot steam. It is to be remarked that this boiler had been the subject of an official examination and report by engineers of the United States Navy, and had been inspected by great numbers of persons, including Mr. Martin, (whose ar- rangement of it is charged as the cause of the explosion,) yet no witness has attempted to explain how the lead could have melted (unless indeed the suggestion of Chief-Engineer Sewell, that the tearing of the sheet created friction enough to melt it- self, may be considered an explanation) or the felt charred, unless by superheated steam ; and Mr. Martin himself remark- ed that the only evidence of low water which he had seen was in the fact of burnt felt, of which he had picked up a sample and then had it in his pocket. It is apparent that the engineer corps of the Navy, as well as the persons whose plans are in- volved, have a deep interest in assigning some other cause than low water, since if it were low, it must have been so either from carelessness of engineers, or from inherent defects in the organization which baffled the ordinary skill of such per. sons as had the machine in charge ; yet no attempt has been made to explain away the melted lead or to reconcile its pres- ence with the fact that there was enough water in the boiler. And as this is the ordinary cause of explosion, it would seem consequently the true one here, particularly since no evidence 132 of any sort has been produced to substitute any other cause, and we are left to the mere suggestion, without proof, that pos- sibly the braces might have been taken out by Mr. Cahill and not replaced, or possibly the cold-water test, which experience has shown to be infallible, has in this case proved a snare. Unfortunately there are other facts which point out very clear- ly the existence of an organic disease in these vessels, requir- ing the utmost vigilance to guard against, the presence of which is abundantly proved. A number of these vessels are just now coming out, and it so happened that on Saturday, the sixteenth day after this explosion, the Pawtuxet, having been run for ninety-six hours at the dock, was taken out on a trial trip from Providence. In the course of the run it became necessary to shut off the steam from the engine from some cause, and thus the fact appeared that the water which had seemed to be abundant in the gauges was low. Mr. Baker, an experienced engineer, who set up and ran the engine on her ninety-six hours' trial, at once had the fires drawn from the furnaces as a measure of safety ; the necessity of which, under the circumstances, Mr. Sewell admitted to you when on the stand ; and it was found that the steam-pump required twenty- two minutes to resupply the boiler with the water found want- ing, although the gauges had given no warning of its absence. But for Mr. Baker, this accident would have probably had its counterpart; and so convinced of the danger of the machine was Mr. Baker, that he refused to come to New- York in the vessel unless he had the control given him ; and he has told us these, facts and sworn to the danger. On the Chenango, the experienced engineers who ran the engine at the dock have told us that they considered their lives in danger from the lia- bility to low water ; and so convinced were they of it that they refused to open wide the throttle-valve, though the United States engineers who were present insisted that the contract required the engine to be run wide open. Mr. Smith, the en- gineer who erected and ran the engine of the Metacomet, another of the same class, has proved here that the water could only be ke^)t in her boilers by so setting the valves that they would not fully open when the engine worked ; and that when those valves were ordered by Mr. Sewell to be set so as to 133 open wider, and the vessel was run from the shop to the Navy Yard, the water worked so that the valves had to be put back to their original position, which was done by himself at the Navy Yard under orders from the Chief Engineer of the ship. The drawings of these engines have been produced before us, and the measurements made of the cubic feet of vacant space which existed in these cylinders between the valves when they are closed, and the piston when at the extreme end of the cylinder nearest the closed valves, and it appears that these spaces are great enough to hold more than sixteen hundred pounds of water at a revolution before they will be filled so as to arrest the motion of the piston as it approaches the end of the cylinder, and compel the opening of the relief- valves, which are placed in each end of the cylinder to prevent the destruc- tion of the engine by the confinement of the solid water in the cylinder; yet it appears here that even more than this quan- tity of water would at times come over from the boiler at a revolution, and that these self-acting relief- valves had to be opened constantly by hand to permit the escape of this enor- mous quantity of water more freely than it could be voided by the self acting valves. When it is considered that only about nine pounds of water in the shape' of steam are needed to make the ordinary revolution of these engines, and that at times they draw even more than three-quarters of a ton of water at a revolution, it is very easy to see how the boilers might be robbed of their water in a very few minutes, and the attention of an ordinary man be eluded. The coal burned by the Che- nango on her trial has been proved, and the amount of steam which that coal produced has been measured on the indicator diagrams which were taken on the trials, by which it is proved that in the form of steam these boilers only evaporate from three to four pounds of water to the pound of coal, whereas if they did not use up the heat by carrying it off from the boiler in hot water, they would evaporate seven or eight pounds of water into steam ; and it is testified to here, and the calcula- tions show upon the indicator diagrams themselves, that these engines must have been working out of the boilers, in water, on an average during the ninety-six hours of the trial, about six times as much hot water as steam. Of the accuracv of 134 such calculation, based upon comparing the weight of coal burned, with the cubic feet of steam used by the engine, you are, perhaps, better judges than I am ; but it is to be remarked that these calculations have been on the table for several days challenging contradiction, and that they are not disputed. It is further proved here that a considerable number of these ves- sels, exactly like the Chenango, have been recently built and tried, an& that they are now awaiting orders for sea ; yet no witness has appeared before us to say that any of the other of these vessels have operated differently from those whose per- formance has been proved ; although there is no want of proof that when these boilers are arranged with a high steam space above the ends of the tubes, and a steam chimney, they do not work out their water. It would have been much more instruc- tive to us if the engineers who have run so many of these low- roofed boilers had been produced, instead of those whose only experience has been with boilers not liable to that difficulty. We are informed by Mr. Sewell that a superheating apparatus has been applied to one of these double-enders, called the Eu- taw, and it appears that a large number of such appliances are being manufactured by order of the Navy Department, to be combined with these boilers in naval vessels, while at the same time a publication had been given in evidence, issued in 1863, un- der the authority of the Navy Department, in which this pro- position is made : " The advantageous use of superheated steam time appears to be confined to the case of bad boilers, . . . and which prime badly," and this proposition is followed by the declaration that " there are insuperable objections to the use of superheated steam, even with bad boilers, . . . particularly on account of its danger, and the complicated system of valves, thereby entailed ; for provision must be made for shutting off at a moment's notice, and resorting to the use of saturated steam." It would seem, therefore, that when the department resorts to the use of an apparatus pronounced dangerous, there could have been no less urgent reason for it than the one that is suggested in the book, which is to convert the water which is "primed," or worked over from the boiler into steam on its passage to the engine; and this of course admits the presence of a large amount of water between the boiler and the engine. 135 The Secretary of the Navy was kind enough, in answer to my application, to promise me that Mr. Isherwood, the Engineer-in- Chief of the Navy, should attend us, and give us the benefit of his knowledge and experience in our efforts to reach the cause of this melancholy disaster ; and in reply to my subpoena, Mr. Isherwood himself sent me a telegram, fixing last Thursday as the day when we might expect him. On that day he was. in New-York as he had promised ; but unfortunately he found the pressure of his onerous duties elsewhere too great to per- mit him to afford us the time for an examination. This I the more regret, as Mr. Isherwood might have satisfactorily ex- plained to us the very urgent reasons which must have con- trolled him in selecting this species of boiler, which by their height are more liable to be struck by shot in action than if the tubes which are used to aid in the production of steam were placed behind or on one side of the furnace, as is usual, instead of on the top of the furnace, as in this case ; and I was the more desirous of receiving that explanation after having heard read the report of the board of eminent engineers who were called by the Secretary of the Navy in January, 1863, to pronounce their opinion on these double-ender boilers, then to be con- structed, and whose report has been produced before us, in which they say that " on the whole we are compelled to con- sider the type of the boiler used in these steamers as inferior to the horizontal tubular boiler, which is generally used by other nations, and by this country in the mercantile marine." But as Mr. Isherwood has been deprived of the opportunity of giving us this information by the pressure of his duties else- where, I am unable to give you any assistance in solving this difficulty. With these remarks upon the testimony, I propose to submit the further consideration of this sad case to your judgment. The effect of this investigation can not fail to be very important in any aspect it may assume. The whole coun- try is interested in knowing the true reason of this explosion. The victims of the disaster exceed in number those who have perished from any explosion which I can now recall to memory ; and, according to the opinion of both scientific and practical men, a repetition of it may be expected at any time to occur, so long as the combination which existed in the Chenango is used. 136 Mr. Dickerson wrote a letter to Hon. Winter Davis, warning him of the danger, when a trial trip was to be made on one of these vessels. Mr. Baker narrowly escaped destruction by explosion, on another one the very day after this accident, and he refused to go on the vessel unless with entire control ; and the practi- cal men who ran this engine at the dock absolutely refused to inour the risk which would be encountered in opening the boiler freely to the engine. Under these circumstances, we should be false to our duty, either as citizens or as officers of the law, if we shrank from placing the responsibility where it belongs. You must guard your minds from being influenced by any other considerations than the testimony itself; and you have no right to find any verdict except one based upon established facts and according to established natural laws. If we should listen to other reasons than those, we might give any number of explanations which imagination could suggest. We find from the published statements that the Board of United States Engineers, which was convened by order of the Secretary of the Navy, to give their opinion on the cause of the calamity, reported that a defective vein in the sheet of boiler-iron caused the accident, and I wished Mr. Isherwood's judgment on that if we could have had it ; yet no witness here has suggested that explanation as possibly true, any more than that Board has suggested weakened braces as the cause. And some have gone so far as to propose the possibility that foul means had been resorted to, such as the use of gunpowder. But we all know that boilers constantly do explode from low water, and that there are but few other causes for explosion known in the world than those which depend upon low water. It is not very surprising, perhaps, that among the great numbers of ves- sels used by the United States and placed in the hand of young men who have had but little experience, and who are employed when there is a scarcity of engineers, on account of the great demand for the services of such men suddenly made by the Navy, that an explosion should occur at some time ; and if the machinery were of the ordinary kind the accident would ex- cite no unusual interest. But when it occurs on machinery peculiar in its construction, and which had been condemned as inferior by an official board of the most eminent engineers in 137 the country, and when it appears that those peculiarities have so exhibited their dangerous qualities as to alarm practical and scientific men, and to induce them to foretell an accident of this kind; and when we find these peculiarities existing on a great number of other vessels just now coming into use, upon which the lives of our fellow-citizens are to be intrusted, then it is of serious consequence, and demands of us to raise a voice of warning in time to prevent any more such horrors as we have witnessed. Our brave men, who are willing to expose their bosoms to the enemy's shot, ought not to be subjected to the chances of a horrible death at the hands of their own friends, and in their own floating homes. 138 THE TWO VERDICTS. We, the Jury empanneled by Thomas P. Nbrris, one of the Coroners of Kings County, State of New-York, to inquire into the circumstances surrounding the death of Joseph A. Cahill,. Alfred Yates, Albert Murray, Martin Mitchell, Frank P. Root, John Ruddy, • John White, John Murphy, Franklin Silver, John M. Smith, John Reilly, James A. Macomby, William M. Weir, Bernard Boyle, James Lyons, Archibald Fleming, Charles Wiles, Henry Livingston, George Wilson, Barney Cannagan, Samuel Randall, Michael Roddy, Wheeler Sherman, William Bons, Eugene O'Heary, John Mahan, William Hickey, James Smith, find as follows : That the Government ordered a number of boilers to be constructed to suit a number of gunboats, of which the Che- nango was one. That Mr. George W. Quintard, of the Morgan Iron Works, New- York, received the order from the Govern- ment for the boilers and engines of the Chenango. That he constructed them according to drawings and specifications mi- nutely given, except the bracing, which was done according to the maker's judgment, under the constant supervision of a Government officer. That they were subjected to the inspec- tion and a test of cold-water pressure on the boilers of fifty- eight pounds on the gauge, and two pounds for the height of the water in the pipe, making, as was supposed .by the officer, sixty pounds of cold-water pressure to the square inch. That the stops w T ere then carefully examined by the boiler-maker to see that they had all sustained the pressure without fracture or giving way, and found to have sustained no damage from this pressure. That they were then run at the dock of Mr. 139 George W. Quintard, as a trial test according to the specifica- tions, for ninety-six hours by experienced engineers, tinder the inspection of Government officers, having at times during this trial a pressure as high as forty pounds to the inch. That the boilers and engines of the Chenango were finally completed and delivered to the Government. That they were then ac- cepted by the Government as correct according to specifications. That the Chenango was then removed from the dock of Mr. Quintard to the Navy Yard in Brooklyn. That on the 15th day of April, 1864, at about quarter before three o'clock p.m., the boat left the Navy Yard, and proceeded down the bay on her first voyage to sea. At Governor's Island the record shows that they had but - twenty -six and a half pounds of steam, and at the Narrows the boiler exploded under a pressure, as the indicator-card shows, of not more than thirty-four and a half pounds. What the immediate cause of the explosion was is shrouded in mystery, for (as in all such cases) the life that could tell is taken away with the disaster, and the living are left to conjec- ture the cause as best they can. That there is great fault in the staying of the boiler from the roof to the tube-boxes is manifest to all. Yet it is impos- sible that it should have given way at a pressure less than tioenty-five pounds, having been tested with cold water at sixty pounds / the braces all carefully examined, and found to have stood the pressure without fracture, and in the face of the evidence that there are eighteen more of them noio running at higher pressures, stayed in the same way and by the same man. But the -well-known laws of science and mechanical arts, so carefully and beautifully brought out during this trial, can, we think, fathom the mystery, and point with unerring .aim to the causes of this disaster. Taking the peculiar construction of the boiler, (drawing the steam, as it did, but eighteen inches above the water-line,) with vertical tubular fire-surfaces placed directly over the crown of the fire-box, throwing the foaming water upward through the tubes as through a series of gun-barrels, and in 140 contact with the steam-pipe that is placed ready to draw it through the engine. The clear evidence that the engine had worked water in large qicantities from the time she was first started — that the pump of nine inches diameter, throwing seventy-two pounds of water to the stroke, while the cylinder required but nine pounds, was unable to keep up a supply, and the tendency of all new boilers to foam, especially when drawn upon beyond their capacity — thus deceiving the engineer as to the true con- dition of the water, and exposing an immediate area of surface (about one hundred and eighty feet less the bore of the tubes) to the intensity of the fire, (for it had but six inches to fall to do this.) generating, as it would with fearful rapidity, a dan- gerous gas, ready to lick up the water at the slightest agitation from without, and expand itself beyond the power of the boiler to resist. The presence of burnt felt and melted lead on the edges of the rupture after the explosion, that can only be accounted for by the escape of this gas. Taking these facts so clearly given, and we need be at no difficulty to account for this explosion, or point directly to its cause. We therefore find that this boiler exploded from low water and superheated steam. Abraham Inslee, Foreman, . William H. Bigelow, Theodore Ovington, Robert G. Anderson. MAJORITY VERDICT. We the undersigned jurors, forming a majority empanneled by Thomas P. JSTorris, Esquire, one of the Coroners of Kings County, State of New- York, to inquire into the circumstances surrounding the death of, [here follow the names of the de* ceased men,] find : That these men met their death from scalds and inhalation of steam on board the United States gunboat Chenango by the bursting of one of the boilers, which was caused by a greater tension exerted on the boiler than it could bear, the result of improper bracing. 141 The stays of the boiler being sixty-four in number, and at- tached to the side of the tube-boxes by thirty-two tugs, where- as the drawing calls for sixty-four braces attached to sixty-four tugs, thereby reducing the strength of the bracing to about one half of that shown in the drawing, also doubling the chances of rupture if a stay, by carelessness, should be left out, and the jurors consider the Inspector of such boilers highly censurable, as they consider it was his duty to have reported * to his immediate superior where so vital a change as this had taken place in the construction of this boiler. We also felt, from the evidence shown, that this accident arose from a gradual increase of tension of ordinary steam, and not from superheated or explosive steam. There is no evi- dence of explosive steam being generated. The testimony of the surviving Engineer and of Captain Fillebrown are conclu- sive that the engine and boilers were in fine working condition, and from the short period of one hour elapsing from the time she left her mooring at the Navy Yard and the time of the accident, and the active circulation of the fluids, renders it an impossibility that the water could have been too low at the time of the accident. These engines returning the water of condensation to the ' boilers, and the foaming taking place during this short period, would have precluded the possibility of the report of the En- gineer, Mr. Cahill, to the Captain. We also believe that the Martin boilers on board such ves- sels, when properly constructed, are not more dangerous than other boilers under similar circumstances. William Arthur, ] Norman Hubbard, | Thomas Kelly, Y Jurors. K. J. Hutchinson, Lancelot Kerkup, ^ LIBRARY OF CONGRESS 029 827 669