STEAM-BOILER INSPECTION AND EXPERIMENTS. 



707 



Quesada and Figueredo were executed at San- 

 tiago. On December 14th the official organ 

 of the Spanish authorities announced that 

 three thousand two hundred insurgents had 

 signed at Puerto Principe a document declar- 

 ing their submission to the Spanish Govern- 

 ment. The -document states that the insur- 

 gents still in the field were, almost exclusively, 

 negroes under the leadership of Ignacio Agra- 

 inonte, who had rebelled against Cespedes. 

 On December 27, 1871, Captain-General Yal- 

 maseda issued a proclamation in which lie says 

 the offer of pardon to the insurgents cannot 

 last forever. He now gives notice that every 

 insurgent captured after the 15th of January, 

 1872, will be shot, and those surrendering after 

 that date will be sentenced to perpetual im- 

 prisonment. The negro men are to be treated 

 the same as the whites. All negro women 

 captured will be delivered to their owners, and 

 will be compelled to wear a chain for four 

 years, and all white women captured in 

 the woods after the 15th of January will be 

 banished from the country. The chiefs of in- 

 surgent bands will be allowed to surrender, 

 until the 15th of January, under the conditions 

 hitherto granted. The Cuban reports on the 

 progress of the war frequently charged the 

 Spanish authorities, and in particular the vol- 

 unteers, with committing the greatest cruel- 

 ties. In November the Spanish authorities 

 ordered a punishment for a political offence, 

 which has been regarded as rash and severe in 

 the extreme, although their reasons have not 

 been stated. Eight medical students, who 

 were found guilty of having demolished the 

 grave of Gonzalo Castanon, were by the court- 

 martial sentenced to be shot, and the sentence 

 was immediately executed. 



STEAM-BOILER INSPECTION AND EX- 

 PERIMENTS. The Steam-Boiler Inspection 

 and Insurance Company at Hartford, Conn., 

 states the results of the inspections made under 

 its direction in the months of November and 

 December, 1871, which are summarily as fol- 

 lows : 



During these two months, 1,490 visits of inspection 

 were made, and 2,965 boilers examined 2,656 exter- 

 nally and 1,096 internally while 240 were tested by 

 hydraulic pressure. The number of defects in all 

 discovered were 1,566, of which 332 were regarded 

 as dangerous. These defects were as follows : Fur- 

 naces out of shape, 71 17 dangerous ; fractures, 99 

 62 dangerous; burned plates, 95 i3 dangerous: 

 blistered plates, 204 28 dangerous; sediment and 

 deposit, 28222 dangerous ; incrustation and scale, 

 235 22 dangerous ; external corrosion, 90 24 dan- 

 gerous ; internal corrosion, 45 7 dangerous ; inter- 

 nal grooving, 38 5 dangerous ; water-gauges defec- 

 tive, 93 10 dangerous ; blow-out defective, 26 9 

 dangerous ; safety-valves overloaded and out of order. 

 4914 dangerous ; pressure-gauges defective, 230 14 

 dangerous ; boilers without gauges, 8 ; cases of defi- 

 ciency of water, 15 2 dangerous ; cases of broken 

 braces and stays, 52 29 dangerous ; boilers con- 

 demned as unsafe to use, 34. Among the defects 

 enumerated, fractures are quite numerous, and they 

 call attention to it from the fact that several cases 

 have been found where the difficulty originated in 

 poor workmanship in the construction of the boiler ; 



for instance, a, case was found where a seam was 

 cracked in line of the rivets for three feet, and on 

 close examination it was ascertained that the defect 

 had its origin with the "drifting-tool." Several 

 similar cases have been met with, and, although pre- 

 senting fractures of less extent, are perhaps none the 

 less dangerous from the fact that a weak point in the 

 boiler is provided, which, upon severe strain being 

 brought, is liable to bo increased suddenly with 

 serious results. Plates often become burned and 

 weakened in places impossible to discover, except 

 the boiler is cold and subjected to both internal and 

 external examination. A case of this kind is the 

 following : The brick-work setting of the boiler had 

 become Droken down on the side against the brick 

 wall of the building. The fire had gone up beyond 

 the water-line, and badly burned and weakened the 

 sheets exposed. The boiler was set with the front 

 in the chimney, and the defect was so far forward 

 that the fire escaped through the break into the 

 chimney. No idea or apprehension of danger was 

 suspected, until a cold examination revealed the de- 

 fect and prevented disaster. More or less ignorance 

 prevails relative to the importance of a good safety- 

 valve. And^ in the fitting up of a boiler, or nest of 

 boilers, the ignorance of the ooiler maker and fitter 

 is often glaringly apparent. There seems to be no 

 calculation made relative to the fitness of appliances 

 for the work required of them. Of course this is not 

 true of those who, by long experience and careful 

 observation, have ascertained just what the wants of 

 a boiler are, but more particularly of irresponsible 

 concerns that have no conception of the immense 

 strain brought to bear on boilers at work, nor of the 

 importance of having all the appliances adapted to 

 the size of boiler, pressure of steam carried, and 

 amount of work required. 



In a large mill using six boilers there was but one 

 safety-valve, and the escape-pipe from this valve 

 was only two inches in diameter. The boilers con- 

 demned were not all beyond repair, though many 

 were entirely worn out. Those capable of being ren- 

 ovated have been put in good condition, and will 

 doubtless last for some time yet. There were twenty- 

 four boiler-explosions during the months of No- 

 vember and December, doing serious damage, and 

 killing 19 and wounding 38. 



Experiments have been made at Sandy 

 Hook, N. Y., by Mr. Francis B. Stevens, of 

 Hoboken, N. J., on steam-boiler explosions, 

 which present the following results : 



The first experiment, November 22d, was made on 

 a boiler built by Fletcher, Harrison & Co., in 1858, 

 and taken out of the steamboat Joseph Belknap, in 

 July last, after haying been thirteen years in use. 



It had been subjected to a hydrostatic pressure of 

 112 pounds per square inch, which broke a few of 

 the braces without altering the form of the semicir- 

 cular top of the rectangular front. After being re- 

 paired, it was again subjected to a hydrostatic test 

 of 82 pounds per square inch, without the rupture of 

 any part ; and again to a steam-pressure of 60 pounds 

 per square inch, without fracture. 



In this experiment the fuel used was wood, and it 

 was intended to burst the boiler by steam-pressure 

 tinder the condition of 12 inches of water above the 

 top of the flues ; but it was found that the pressure 

 could not be raised above 93 pounds per square inch, 

 owing to the excessive leakage of steam from the 

 seam joining the steam-chimney to the boiler-shell. 

 At the above pressure no fracture occurred, but the 

 form of the semicircular top of the rectangular front 

 underwent a change. The experiment was only of 

 value in showing the strength of a boiler of this type 

 and construction after thirteen years' service in a 



The next experiment was made on a rectangular 

 box, built to represent the fiat water-space or water- 

 leg of the Westfield's boiler, recently exploded at 



