Many of our readers doubtless recollect the history of a terrific explosion that took place on board the ship European, when lying in harbor at Colon, Panatna, on April 3, 1866. Amongst the-cargo put on board at Liverpool were 70 cases of nitro-glycerine, and one case containing 70,000 percussion caps. At 7 A.M., on the 3d, a most tremen dous explosion occurred in the after part of the ship. It was described as most rapid, Without smoke, but with a great flame, and the ship was immediately after seen to be on fire. -The whole of the deck and cabin aft were carried away, and the side of the ship was also much damaged, the plates above the water line being blown away, and the parts below it being much injured. For fear of further explosion, the ship was towed into the bay, where she shortly sunk. Nor was the injury confined to the European ; the jetty was nearly blown away, and it vessel lying on the other side of it was ranch damaged. Houses in the town were also partially destroyed, the floors in many cases being torn up; and altogether about 50 lives were lost. Wimn the bodies were recovered, they presented no sign of smoke nor any symptoms of scalding; and hence it. was inferred that the explaion could not havo been produced either by the percussion caps or by steam. On these and other grounds, the conclusion was irresistible that the explosion was due to the nitro-glycerine. An action was (Aug. 1867) brought at Liverpool by the owners of the European against the shippers of the nitro-glycerine, on the groin:A that no due notice of the dangerous properties of that compound bad been given; and at this trial, several of the important points regarding the explosive properties of nitro-glycerine, which we have noticed, were elicited from prof. Abel, chemist to the laboratory at Woolwich; col. Boxer, superintendent of the Woolwich laboratory; and prof. Roscoe, who appeared as scientific witnesses. To give sonic definite idea of the explosive force of this' substance, prof. Roscoe stated that one case of it would have sufficed for the destruc tion of the European. It is used to a considerable extent in the slate quarries in Wales, and in mining operations. A workman at one of quarries described how he had been set to clean II wagon which had held some of it, which he did by scraping it with a piece of slate; and inadvertently throwing the piece of slate into the wagon when he had finished, the percussion exploded the remnants of the oil, and the wagon was blown to pieces. He states that it is regarded as ten times as powerful an explosive agent as gunpowder.
We learn from a number of the Nevada Gazette (quoted in the Chemical News, Aug. 16, 1867), that this substance was very advantageously employed in the blasting necessary for the construction of the summit tunnel on the Central Pacific-railway. The operation is said to have been carried on 25 per cent faster than if powder had been used. The small holes required for the oil can probably be drilled in less than one-third the time required for the larger ones necessary in using powder. The oil does much more execu tion than powder, as it always breaks the rock from 2 to 16 in. beyond the hole, and also throws out a much larger body. The oil was estimated as having, iu hard rock, a strength five times greater than powder. It was made upon the spot, and was con
sidered much stronger as well as safer than the imported compound. After havin7 been used for several months, there had been no accident, nor had a single blast missed fire since the Chinamen commenced filling the cartridges. Col. Schaffner of the U. S. army published an official report on this compound, to which he gives the name of " nitroleum,' which confirms the fact that its explosive properties are far greater than those of gun powder. From a report on the same subject by rapt. Grant, R.N., it appears that it is exploded by percussion, and apparently, under ordinary circumstances, by nothing else —neither by friction nor fire. Generally is trifling blow is sufficient to explode it. Its explosive force is about ten times that of gunpowder. It has all the appearance of com mon oil, and is usually carried in tin cases, each of which holds 25 lbs. Each can is packed in a wooden case for carriage. In a paper on this subject by M. Kopp, that chemist holds the view already noticed, that accidents are mainly due to the presence of impurities. He states. that, by means of charges of 1500 or 2000 grams of oil, from 40 to 80 cubic meters of a hard rock may be detached.
We have already noticed Richter's observations on the slight inflammability of this compound; and as the employment of this explosive agent seems to be increasing, we shall give his other chief results, so as to bring up our knowledge to the latest possible date. The shaft in which the experiments were made was being sunk 30 ft. long by 8 ft. wide, in hard gray gneiss with occasional joints, which facilitated the working. From these experiments it appeared not only that its power was four or five times greater than that of the nitrate-of-soda gunpowder commonly used for mining purposes in Germany, but that other advantages accrued from its use, which may be summed up as follows: (1.) Fewer men are wanted for working out a certain-sized piece of ground, and fewer holes have to be bored than at present. (2.) Nitro-glycerine does not take fire easily (see above). (3.) The amount of smoke after a Nast is small, as compared with that of pow der; and workmen can return at once to the spot when the blast has taken place. (4.) Holes that have missed, or only partly torn, can he retamped and shot off, which, with the present arrangements. is impossible, or very dangerous. Against these advantages must be set off the following disadvantages: (1.) The gases formed during the explo sion of nitro-glycerine have an injurious effect on the organs of sight and respiration.
(2.) Nitro-glycerine explodes on being struck smartly, and easily freezes. (3.) The masses of rock which it removes are mostly very large, and considerable time has to be spent in breaking them up.
In another s(7d, of experiments, the relative cost of blasting by nitro-glyeerine and gunpowder was compared, and it was found that a cubic fathom of ground could he removed by the former for £4 Os. 4d.; the cost amounted to £5 Os. 91d? when the latter was used. In sinking a shaft in clay-slate by means of nitro-glycerine, the cost was under £3 per cubic fathom. For further details regarding these experiments the reader is referred to the Chemkal News, Nov. 15, 1867, ;OA contains a translation of Richter's valuable memoir.