Use of the Galvanic Battery in Blasting. 33 
Art. IV.—On the use of the Galvanic eon, in Blasting ; by 
Hamiuron K. G. Mor 
To the Editors of the Philosophical Magazine and Journal, (Lond ) 
Johnstone Castle, Wexford, May 24, 1839. 
G'entlemen—I Bre to trespass on your time by this letter on 
the use of the galvanic battery, instead of the fuze in blasting. 
The papers have given short descriptions of the experiments 
made at Chatham, but all the details were not given. I com- 
menced my experiments on blocks of the old trees that were 
blown down by the late storm. I first prepared an igniting car- 
tridge by joining two pieces of clean copper wire to the extremi- 
ties of a steel wire taken from the scratch brush, such as is made 
use of by gun-makers; this steel wire is fastened to the copper 
wires by waxed silk ; the length of steel wire to be deflagrated is 
one-fourth of an inch; a piece of very slight wood is spliced to 
both copper wires to protect the steel wire from any accident—it 
makes the whole strong and more convenient to be introduced 
into the small cartridge, which is either a quill or a small paper 
tube. They are filled with fine powder, and made air and water- 
tight, to prevent the powder from getting damp and rusting the 
steel wire; a second small piece of wood is then fastened to this 
‘small cartridge and the copper wires; one of the wires is bent 
_ over this piece of wood and brought up at an angle with the 
other upright wire. This is my exploding cartridge: it cannot 
be easily put out of order. The wires of the cartridge have only 
_to be made bright before they are fastened, by twisting them 
round the positive and negative wires of the battery. I always 
place the cartridge deep in the hole made to receive the powder, 
in order that the pressure from the turnpeg may be taken off by 
the quantity of powder above it. 
The wire I made use of is the common copper-bell wire. The 
battery is the old Wedgwood trough, with 4-inch plates, double 
coppers. I prevent the zinc plates from touching the copper by 
small pegs of wood passed through the four corners. Wooden 
troughs with movable divisions were tried, but not with any 
good result. A wooden trough with the plates in a frame of 
wood, with varnished paper between the copper, was tried, but 
‘i 8 i pomntrena trough far surpassed them. My first experiment 
Pi 5 
}. xxxvin, No. 1.—Oct.-Dec. 1839. _ 
