uld not be made at that time, because the
tasimeter adjustment was too delicate, and at the best the galvanometer
deflections were so marked that they could not be kept within the
limits of the scale. The sensitiveness of the instrument may be easily
comprehended when it is stated that the heat of the hand thirty feet
away from the cone-like funnel of the tasimeter will so affect the
galvanometer as to cause the spot of light to leave the scale.

This instrument can also be used to indicate minute changes of
moisture in the air by substituting a strip of gelatine in place of the
vulcanite. When so arranged a moistened piece of paper held several feet
away will cause a minute expansion of the gelatine strip, which
effects a pressure on the carbon, and causes a variation in the circuit
sufficient to throw the spot of light from the galvanometer mirror off
the scale.

The tasimeter has been used to demonstrate heat from remote stars
(suns), such as Arcturus.

VIII. THE EDISON PHONOGRAPH

THE first patent that was ever granted on a device for permanently
recording the human voice and other sounds, and for reproducing the same
audibly at any future time, was United States Patent No. 200,251, issued
to Thomas A. Edison on February 19, 1878, the application having
been filed December 24, 1877. It is worthy of note that no references
whatever were cited against the application while under examination in
the Patent Office. This invention therefore, marked the very beginning
of an entirely new art, which, with the new industries attendant upon
its development, has since grown to occupy a position of worldwide
reputation.

That the invention was of a truly fundamental character is also evident
from the fact that although all "talking-machines" of to-day differ very
widely in refinement from the first crude but successful phonograph of
Edison, their performance is absolutely dependent upon the employment of
the principles stated by him in his Patent No. 200,251. Quoting from the
specification attached to this patent, we find that Edison said:

"The invention consists in arranging a plate, diaphragm or other
flexible body capable of being vibrated by the human voice or other
sounds, in conjunction with a material capable of registering the
movements of such vibrating body by embossing or indenting or altering
such material, in such a manner that such register marks will be
sufficient to cause a second vibrating plate or