Mr. Edison, the inventor of the phonograph, gave exhibitions with the instrument to-day at the Capitol in the presence of a large number of Senators and Representatives.  Messrs. Garfield, Cox, of New York, and others, spoke in the phonograph and their voices and speeches were reproduced with remarkable accuracy, the volume and peculiarity of sound and emphasis of each speaker being plainly recognized.  In an interview published in the Star Mr. Edison describes a marvelous discovery recently made.  He says: "Night before last I found out some additional points about the carbon which I use in my carbon telephone. It may be used as a heat measurer.  It will detect one-fifty-thousandth of a degree, Fahrenheit.  I don't know but what I can make an arrangement by which the heat of the stars will close the circuit at the proper time automatically and directly.  It is a curious idea that the heat of a star millions of miles away should close a circuit on this miserable little earth, but I do not think it is impossible."  Of the practical uses for which the phonograph may be made available, Mr. Edison says: "I expect to have my improved phonograph ready in four or five months.  This will be useful for many purposes.  A business man can speak a letter to the machine, and his office boy, who need not be a shorthand writer, can write it down at any time, as rapidly or slowly as he desires.  Then we mean to use it to enable persons to enjoy good music at home.  Say, for instance, that Adelina Patti sings the 'Blue Danube' into the phonograph, we will reproduce the perforated tinfoil on which her singing is impressed, and sell it in sheets.  It can be reproduced in any parlor with equal fullness and about one-half the original volume.  In the same way the tones of a great elocutionist can be preserved and heard.  The President of the American Philological Society wants one of my improved phonographs to preserve the accents of the Onondagas and Tuscaroras, who are dying out.  One old man speaks the language fluently and correctly, and he is afraid that he will die.  The phonograph will preserve the exact pronunciation."