331 



THE CIVIL ENGINEER AD ARCHITECT'S JOURNAL. 



[Oct. 



ship.* Almost all tabular boilers have flat plates in front. If I used a flat 

 plate, I should construct it in such a manner that the stays themselves 

 might sustain tlie entire pressure. If the valves were tied down and the 

 boiler was subjerled to a strain of considerably above GO lb., ihe effect 

 would be gradually to weaken the boiler. All the parts of the boiler made 

 to resist the strainins would be acted upon by such a constant pressure. 

 The dome would not be alTerted by the pressure of 13f) lb., which I applied 

 to the nnexploded boiler. The vulnerable part of the boiler is the bad 

 plate in front." 



The inquest was again adjourned, and was resumed on the 24th, when 

 .several additional facts were elicited, Heasnian, the person who acted as 

 engineer on the day of the explosion, denied positively that the valves 

 were tied down, and he said that only a minute before the explosion the 

 gauge indicated a pressure of but 3S lb. to the square inch, and the steam 

 was blowing off slightly from the loaded valve. He was equally positive 

 that there was no string whatever attached to the lever of the larboard 

 boiler at the time, as it had been shaken olT on the Sunday morning pre- 

 viously, and had not been replaced. Mr. Lloyd was again called, for the 

 purpose of explaining a few points of his former evidence. He stated, in 

 confirmation of his opinion that the pressure at the time of the explosion 

 must have been at least 136 lb. to the inch, that the companion boiler had 

 been so much strained at the same time, that it could not have worked 

 afterwards, owing to the leakage ; and yet, in this weakened condition, it 

 bore a pressure of 136 lb. to the inch before it gave way. Mr. Joyce and 

 his foreman, Mr. Mearham, gave evidence. The latter states that when 

 the boilers were delivered from Mr. Trotman's, of Whitecross-street, 

 borough, they were proved to a pressure of 1.50 lb to the square inch. 

 The boiler was again proved to a pressure of 1.50 lb. on the 3rd of 

 August, when Ihe lubes were repaired. That pressure was not observed 

 to make any impression on the boiler. When he visited the boat on the 

 !3rd of August, he ordered the strings on the levers to be cut away. as 

 there had been a talk about Clark having lied down the valves ; but, 

 having himself confidence in Clark, he did not believe that he " had ever 

 done so wicked a thing." Had any one of the four valves been in opera- 

 tion, be was of opinion it would have been enoiigh to relieve the boiler 

 from dangerous pressure. The weight on the lever would be equivalent, 

 as slated by Mr. Lloyd, to a pressure of 66 lb., if placed at Ihe end of the 

 lever ; but it never could be brought within three inches of the end, owing 

 to the waste steam-pipe, and Ihe pressure could not then exceed 561b. or 

 57 lb , or, with Ihe lever and valve, 59 lb. Mr. Lloyd's proof was made 

 after the boiler had lost its slays. Had it been made when the boiler was 

 new, and with the stays in, he believed it would have supported a pressure 

 •{ 250 lb. 



Mr. .Joyce said that Mr. Trotnian had his own price for the boilers, and 

 he had reason to believe they were quite sound. In reference to Mr. 

 Lloyd's opinion, that boilers ought to be proved to ten times the working 

 pressure, Mr. Joyce observed that he never knew a boiler that would 

 stand such a test. The front plate of the Cricket's boiler was made of 

 B. B. H. iron, which is of very good average quality. The boilers of the 

 Ant and Bee are of good Slaffordshire iron, and the tube plates are not so 

 thick as those of the Cricket. 



Mr. Trotman, the maker of the boilers, gave the following evidence: — 



*' 1 have been a boiler-maker from my youth. T furnished the boilers of 

 the Cricket. Mr. Joyce said they were to work from JOlb. to 50 lb., but 

 never to exceed 50 lb. I proposed to prove them to 100 lb , and Mr. Joyce 

 said he should be very well satisfied. \l hen they were done, he offered to 

 prove them himself, after they were delivered, and I consented. I filled 

 them with water, to discover any leaks, but did not prove their strength. 

 I saw the exploded boiler Ihe Sunday after the accident. I concluded 

 there had been some unfair work. I don't Ihink Ihal any ordinary pres- 

 sure could have bent the plate and lorn the angle-iron, which was very 

 strong. I had the iron from Messrs Moser, in the Borough : I paid 15i. 

 a ton for Ihe tight iron, and 20i. a ton for that of the two plates. I have 

 worked torts of the B. B. H. iron, and consider it next to the Low Moor. 

 The engineers fix on the safety valves. With fair pressure and fair work, 

 those lioilers would have worked for years. They have been known to 

 work at 80 lb., and Ihat is much more than I was told would be required, 

 1 have never known a boiler so strong as to resist a pressure ten limes the 

 ordinary amount. This accident must have been occasioned by pressure, 

 which must have been excessive to send part of the botler. weighing per- 

 hiips a Ion and a half, through the stern of the boat, and about forty yarJs 

 through the water." 



Mr. Robert Kettle, of Ham, civil engineer, though he admitted he had 

 never seen the valves nor the boiler, spoke confiilently that the cause of 

 the explosion was the overheating of the flues, that the stoppage of the 



* [We thinit Mr. Lloyd must here allude to low-preBstire boilers, where the steam is 

 rarely generated at a higher pressure then 101b. or 121b.]— Kditor. 



valves was quite inadeqaate to account for the explosion, and that the 

 pressure must have been nearer 300 lb. than 150. 



The evidence having been concluded, the coroner (Mr. Bedford) summed 

 up, and the jury, after deliberating for an hour and fifty minutes, delivered 

 the following verdict; — 



" We finrl that Thomas Shed, John Blunt, John Littleton, George Shnte, 

 and John Buckley came to their deaths by the bursting of the boiler of 

 the Oicket steamboat, on the 271h of August, 1817. We find a verdict of 

 mnnstaughter iif^ahist Henry Heasmnn, the engineer on that day. We con- 

 sider Clark highly culpable, and unfit to hold the situation of engineer. 

 We likewise consider Mr. Smith's conduct shamefully neglectful in not 

 properly investigating the complaint made against Clark." 



The foreman stated that they were unanimous in their verdict. The 

 inquisition was then signed by the jurors, and the coroner made out his 

 warrant for the commitment of Heasraan. 



Thus has terminated this important inquiry, which lasted seven days, 

 and on the last occasion the jury sat from ten in the morning till ten at 

 night. In an engineering point of view it possesses great interest, and 

 the evidence given respecting the explosion, and the experience gained by 

 it, will, we trust, operate in giving additional protection to the public 

 against such disasters in future. 



CONSTRUCTION OF PENITENTIARIES. 



The following propositions on the construction of prisons were discussed 

 at a meeting of delegates from the ditferent European Governments, met 

 last month at Brussels, to take into consideration Penitentiary discipline. 

 The meeting was attended by Major Jebb, sent over by our Government, 

 Mr. Rolch,and Mr. Pearson, from England : — 



"The buildings should be disposed in such manner as to facilitate tha 

 various duties, without any confusion. To that effect it is indispensable to 

 separate the prison, properly so called, from the accessory localities de- 

 stined for the directors and other persons employed. The external com- 

 munications may be maintained without exercising any influence on the 

 preservation of order wilhin. With that view messengers, purveyors, &c., 

 should never come into contact with the prisoners. Each branch of the 

 service should be carried on in some respects in an inilependeut manner, 

 with reference, however, to the principal direction from n hich it receives 

 its impulse. 



Central Observatory. — The various parts of the buililing should be 

 connected with a central point of inspection, from wirich the head of tire 

 establishment may inspect, without being under Ihe necessity of moving, 

 all the essential branches of the service. Regard must be had to the inter- 

 nal distribution of the localities, to the arrangement of the galleries, and to 

 the choice of the materials of construction, in order that no material obsta- 

 cle may thwart that inspection. 



Cells. — In the disposition and arrangement of the cells, regard must be 

 had to Ihe following conditions:— 1st. The cells must be large enough to 

 allow of the prisoners' taking exercise, carrying on trades, and enjoying 

 sufficient space and air for the preservation of their health. The space 

 should vary from 28 to 35 cubic metres. 2nd. They should be lighted irp, 

 ventilated, and heated in a suitable manner. 3rd. Their constructrou 

 should be such as to allow of no commnnicalion between therr inmates. 

 4lh. They should be furrrished with bed and bedding, with a fixed wash- 

 hand basin with a tap, with a water-closet and with other necessary arti- 

 cles. The prisoners should also have the means of giving Ihe alarm to the 

 attendants in case of illness or accident, or under any circumstance in 

 which their presence might be necessary. 5th. The prisoners should be 

 sutyect to an easy but unperceived inspection. 



SpKClAL Cells. — In penal prisons it is necessary to have a certain num- 

 ber of special cells for the irrfirruary, for special punishments, for Ihe diffe- 

 rent callings, and for prisoners on their first arrival. The cells for in- 

 firmaries, chiefly reserved for parients who cannot be suitably attended to 

 iu the ordinary cells, should be more spacious than the former, and should 

 be disposed in such a manner as to allokv of the free access of the atlendauLs. 

 One cell of that kind for every 40 or 50 prisoners would possibly be suffi- 

 cient. Cells for punishment should be stronger than others, and should be 

 built in such a manner as to be easily darkened, if necessary. One such 

 cell would be siiflicient for about 100 prisoners. Tire dimensions of the 

 cells for the exercise of certain trades should correspond with the use to 

 which they are to be put. They should be situated in preference on the 

 lower stories, and their number must depend on the nature of the trades 

 carried on in the prison. In prisons where prisoners are constantly arriv- 

 ing, a certain number of cells should be made in which each prisoner may 

 be placed temporarily, previous to being seen by the surgeon, and suck 

 cells might be of smaller dimensions than others. 



Heatino and Ventilation. — Whatever the system of ventilating bT 

 heating may be, its results should be the following :— A sufficiency to eaih 



