Description of the Steam Pyrometer. 99 
be found expedient to allow a moderate discharge only at the mouth 
of the pipe, and to cause the greater part of the action to take place 
through the metal of the receiver R. The only uses indeed of this 
part of the apparatus are Ist, to receive, without loss of heat, the 
standard piece I, and deposit it in the water without coming in con- 
tact with the exterior air, and 2d, to prevent the dispersion of the 
water by the extreme rapidity of its action, particularly towards the 
close of the operation. The pipe of R, is wrapped with flannel. 
The manner of transferring the standard-piece is seen in Fig. 3, 
where G is a cyMndrical or slightly conical recipient either entirely 
closed, or having a few orifices h, h, h, at the bottom. This recip- 
ient is to be formed either of iron, copper, silver, platina, plumbago, 
wedgewood ware, or crucible clay, according to the heat to which it 
is to be exposed, or the materials into which it is to be plunged. It 
will often be found expedient to protect the cylinder I, from the di- 
rect action of the fused metal, of which we would ascertain the tem- 
perature, otherwise there might be an adhesion of some portions of 
the melted mass which would vitiate the experiment. When the 
body I, has been heated to the requisite degree, and is to be trans- 
ferred to the receiver R, the container G, is laid, by means of the 
handle, g, w, on some convenient support; R is then inserted at the 
mouth so that the hook p, shall be on the same side with the handle ; 
G and R are then inclined so that I may slide from the bottom of G 
into R, the latter is then rolled over upon the side p, when the concave 
base of J, will be received upon the hook, and the cylinder will take the 
position indicated by the dotted figure, the moment R is raised to. a 
vertical position. 
It may then be plunged in an instant into the boiling water, as seen 
in Fig. 2. The quantity of vapor produced, is shown by the weights 
W, w, which it may be necessary to add to A in order to restore the 
position of the beam, so that the index EH, shall again point to an en- 
graved line on the side of the bar. 
The receiver R, may be kept in the water wlien not required for 
immediate use, and be weighed with the liquid both before and after 
the experiment. By this means its temperature will be the same as 
that of the water, and no calculation necessary. 
The lamp L, instead of being removed by revolving to allow the 
generator A, to rest on the cushion B, may rise through the center of 
that cushion, which may, in turn, be supported by the rod attached 
ats. ‘This arrangement is seen at B, Fig. 2, where the rod Q, sus- 
tains a small circular platform and cushion, as well as the lamp L. 
