370 
DYNAMITE. 
Mr. Unge, who has blasted with nitro-glycerine an extensive tunnel through Stock¬ 
holm, states the saving to have been 23 per cent, on the cost of blasting, and the pro¬ 
gress of the tunnel 87 per cent, quicker than when gunpowder was used. 
These results show that even in the present state of comparative inexperience in the 
use of the new explosive, a great economy is obtained. 
The saving of labour which dynamite causes is its greatest feature. Next to that we 
must class the saving of time. Nearly every mine is dependent on the progress of its 
shafts and pits; and as for railway tunnels, the famous one through Mont Cenis is only 
a glaring example of the necessity of quickening the tedious work. 
Next to the saving of time ranks its peculiar adaptability to wet ground, since water 
has no effect on the charge. Every miner has had more or less experience how difficult 
it is to blast with gunpowder wherever the rock is water-bleeding, which is only too 
common. 
Another sterling advantage of dynamite is that it needs no tamping, and consequently 
does away with a great number of minor accidents, which are little thought of in general, 
being too common to be reported in the daily papers, but form nevertheless a very long 
and sad list of continued calamities. I was told in Cornwall that by far the greater 
number of accidents, occurring in the mines of that county, are due to the act of tamp¬ 
ing. It is abuse, I admit, for a hole may be tamped without firing the charge; still, it 
is very desirable to provide against a source of accidents which, after centuries of ex¬ 
perience, still continue to exact such numerous victims. 
It would be a great drawback on the advantages here set forth if, as has been some¬ 
times asserted, the fumes of nitro-glycerine or dynamite were of a noxious nature. The 
best answer, perhaps, to those who maintain that opinion, is that a great number of 
mines are daily using it for underground work, and that the miners do not at all com¬ 
plain. The truth is that when nitro-glycerine is allowed to leak into the crevices of a 
borehole, it does not all explode, and being dispersed in the atmosphere causes a severe 
headache. It is, however, easily remedied by using cartridges, which prevent leakage, 
and in the case of dynamite, which is a solid, that inconvenience falls away entirely. 
Since that explosive became introduced no complaints have been made, and the work¬ 
men in many mines assert that dynamite cannot be nitro-glycerine, because the fumes 
are so different. 
So far its properties, and now we will examine the practical results. 
The introduction of dynamite is so recent that its advantages over other blasting 
agents cannot be proved by statistics. But in all except danger it is so analogous to 
nitro-glycerine, that the results obtained with the latter will allow us to form a clear 
estimate of its commercial value. Sweden is the only country where nitro-glycerine has 
been in use ever since 1865; it is therefore the most conclusive example. The sales in 
that country, as estimated from the books of the Nitro-glycerine Company at Stockholm, 
were, in 1865, 32,2581b.; in 1866, 48,7851b.; in 1867, 76,5751b.; and during the first 
six months of the present year reached 64,293 lb. These figures show a steady and rapid 
increase. The quantities are not enormous, but it should be borne in mind that Sweden, 
although an extensive country, is not a very productive one, and that Cornwall alone 
consumes three times as much gunpowder as the whole of Sweden. The sale of 221,9001b. 
of nitro-glycerine in that country, equal to at least 2| million pounds of gunpowder, is 
therefore a proof of decided success. If the material had, over gunpowder, the advan¬ 
tage of cheapness, weight for weight, the demand might possibly be ascribed to futile 
and mistaken economy; but as 1 lb. of nitro-glycerine costs the miner as much as 8 lb. 
of gunpowder, it is evident that it must do some work or he would not have it. 
It has no doubt greatly facilitated the introduction of nitro-glycerine into Sweden 
that the transportation, storage, and use of the quantity above-mentioned, has caused 
no accident of any serious nature, and positively a less total of minor accidents than if 
gunpowder had been used in its stead. That immunity from danger is, in all probabi¬ 
lity, due to the colder climate of Sweden, which allows of nitro-glycerine being trans¬ 
ported, nearly all the year round, in a congealed state, its freezing-point being as high 
as 50°. 
In this country nitro-glycerine, notwithstanding the strong dislike which generally 
prevails against it, has been constantly used in the quarries of North Wales since 1866, 
and is in high favour with the miners. Two quarries alone (Brynderven and Driwrwic) 
have up to this time consumed about £3000 worth of the material, or about nine tons; 
