Hudson and Mohawk Rail Road. 141 
touching the tube, at any point above that where the finer portion 
alone intervenes. ‘T’o the outside of the tube a copper wire about 
No. 16 is soldered, long enough to extend to a stout copper wire pro- 
ceeding from one of the poles of a galvanic deflagrator or calorimo- 
tor. The wire passing through the cork, from the inside of the tube, 
is in like manner made to communicate with the other pole. The 
connections between the wires, and the poles, should be made by 
means of soft solder, previously to which we must imagine that the 
tube has been introduced into a perforation made for its reception in 
arock to be blasted. ‘The tin tube may be secured within the rock 
by the usual method of ramming in brick dust or sand, by means of 
a punch, having holes for the protection of the wires of communica- 
tion already described. : 
The apparatus being thus prepared, by a galvanic discharge, pro- 
iby the movement of a lever through a quarter part of a circle, 
the finer wire is ignited, in the place where it intervenes solely in the 
circuit, so as to set fire to the surrounding gunpowder. 
As the enclosure of the gunpowder in the tube must render it im- » 
possible that it should be affected by’ a spark elicited by ramming, as _ 
no means of ignition can have access to the charge besides the gal- 
vani¢ discharge ; and as this can only occur by design, without an 
intention to commit murder or suicide, or unpardonable neglect, it is 
inconceivable that an explosion can take place in this method of blast- 
ng, When any person is so situated as to suffer by it. 
' must be obvious that in all cases of blasting under water, the plan 
of the tin tube, and ignition by a galvanic circuit, must be very eligible. 
Mr. Shaw is now in Philadelphia, and I hope he may meet with 
the Patronage which his project merits. 
August, 1931. 
Arr, TT Soe account of the Hudson and Mohawk Rail Road ; 
by §, DeWirr Bioopcoon, Corresponding Secretary of the Al- 
bany Institute, : 
PEs disparagement to similar works which have tie: 
wu € Hudson and Mohawk Company, it may nevertheless be 
Bite as the most important, from its position, of any yet con- 
in the United States. Albany, when in its infancy, was call- 
=a the 4ppropriate title of “the net,” since it caught all the travel, 
*s. 
