h a double grating of parallel slits lying bolic curve, C C, serves to concentrate the beam and to re- close to one another, one of which was fixed, the other mov- the battery, P, cannot go round the telephone circuit with- able and attached to a vibrating diaphragm. When these flect it down upon… … Responsibility of Employers. the speaker's tones. Fig. 3.-SECTION OF THE SELENIUM RECEIVES. The great diffioulty to be overcome in the use of While a boy of 16 was at work upon a printing press disk to the next. The special advantages of the "cell" in the press room of a New York paper the press…
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