DYNAMITE. 
369 
A mining accident would almost be a rarity, and it is really a proof of the safe properties 
of nitro-glycerine that accidents have occurred almost only on those occasions (as at 
Aspinwall and San Francisco) when it was forwarded under a wrong declaration, and 
consequently the necessity of cautious handling could not be known. 
These hints will give sufficient insight into the importance of converting nitro¬ 
glycerine into a solid. It is not only a theory or some demonstrative experiments on 
which I base that assertion, but also on practical experience. Dynamite has only re¬ 
cently grown to be an article of commerce, yet the quantity sold hitherto exceeds fifty 
tons, and the most serious accident it has caused was the case of a man who, having 
lighted the fuse, kept the cartridge in his hand till it exploded and blew off his arm. 
No explosive can be safe against accidents of that kind. 
Besides the security derived from its solid form, dynamite has over nitro-glycerine 
other special advantages. Its sensitiveness to concussion is, as I have already stated, 
reduced in a very high degree, and since fire does not cause it to explode, it offers great 
security for transportation and storage. Besides, it is quite natural that miners should 
prefer, as more practical, a solid to a liquid explosive. Dynamite is now generally sold 
in ready-made cartridges, and nearly all the workman has to do is to put them into his 
borehole and fire. 
Having now compared the two explosives, nitro-glycerine and dynamite, and shown 
the reasons why the latter, with equal power, is far superior to the former in point of 
safety and facility for use, I will briefly point out the sterling properties which render 
nitro-glycerine such a highly valuable blasting agent. The merits of dynamite are 
essentially the same, so that what is said of one is in the same measure applicable to the 
other. 
The miner’s work is divided in two parts, viz. to make a chamber for the explosive, 
and to charge it. If that chamber was a matter of small expense, it might be very im¬ 
material whether Ihe amount of power required to do the work occupied a great or small 
bulk. But drilling holes in any rock, and especially in hard ones, is a slow and tedious 
labour, and there are mines where it takes a man three days of hard work to make a 
1 in. hole of only 24 in. depth. Three days’ labour, exclusive of tools, represents at 
least 9s., yet the charge of gunpowder which can be lodged in such a hole is at most 
six ounces, or a value of less than 2 d. It is easy, from such an example, to see why the 
miners should be anxious for a more powerful explosive, and ready to pay a much higher 
price for it. The instance here given is almost an extreme one, yet even in rock of very 
little hardness the cost of labour always greatly exceeds the value of the explosive used. 
It needs no explanation why an explosive containing, within the same bulk, ten times 
more power than gunpowder, should greatly reduce the number of boreholes and warrant 
a common saying amongst the workmen in Sweden, that they would blast with nitro¬ 
glycerine even if they could get gunpowder for nothing. 
I have been frequently asked for a positive statement as to the economy in labour 
which the use of dynamite effects. This, however, is a question which cannot be 
answered in a positive manner, for every kind of rock would require a special estimate 
based on its hardness, the nature of the strata, etc., and which greatly vary, not only in 
different localities, but within the limit of a single mine. Every one will therefore have 
to form his own estimate, but as far as I have been able to ascertain, the use of dynamite 
or nitro-glycerine generally causes a reduction of at least one-third on the general cost 
of blasting, which is a very great saving indeed, considering that the cost of the explosive 
rarely figures for more than ten per cent, of the expense. 
I am, however, not in a position to give on this subject as full information as I might 
desire. The miners are generally extremely sparing in communications of that kind. 
Amongst my correspondents I can find only one who gives clear and positive statements 
in figures of the saving effected. It is Mr. Alexander, manager of the “ Phoenix ” mine, 
on the Lake Superior. His letter is dated February 2, 1868, and the mine had up to 
that time used 7000 lb. of nitro-glycerine (they have no dynamite yet), so that the re¬ 
sult is certainly based on sufficient practical experience. The material had been pur¬ 
chased from New York at the price of 1 dol. 50 cents per lb., irrespective of the cost of 
transportation to the Lake Superior. 
Another statement in figures is that of Mr. Nondenfelt, director of the Great Northern 
Railway, in Sweden, who, as far back as the 19th July, 1865, asserted that the use of 
nitro-glycerine had allowed his contracting for blastings with a reduction of 25 per cent. 
