68 Dr. Hare's Improved Eudiomeiers. 
having proved insecure, a new and unobjectionable method 
has been adopted. 
A Fig. 1. 
ae 
wh 
In the instrument represented by the preceding cut, the 
igniting wire is soldered into the summits of the two brass 
wires (WW), which pass through the bottom of the socket 
(S), parallel to the axis of the glass recipient (G), within which 
they are seen. One of the wires is soldered to the socket, 
the other is fastened by means of a collar of leathers, packed 
by a screw, so that it has no metallic communication with the 
other wire, unless through the filament of platina, by which 
they are visibly connected above, and which | have already 
called the igniting wire. The glass has a capillary orifice at 
the apex (A), which by means of alever and spring (appa- 
rent in the drawing) is closed, unless when the pressure of 
the spring is counteracted by one of the fingers of the ope- 
rator. The sliding rod (seen at R) is accurately graduated 
to about 320 degrees. | 
So easy is it to manipulate with this instrument, that any 
nymber of experiments may be performed in as many min- 
utes. The ignition of the platina wire, is caused by either of 
four calorimotors, each consisting of four plates of zinc, and 
of five of copper. They are all suspended to one heam, a 
may be seen in fig. 2. following. 
