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Scientific American, Vol. 81, No. 7 (August 1899) (1899)

leaf 3

An illustration from Scientific American, Vol. 81, No. 7 (August 1899), 1899, leaf 3
- tant this may have been. As far as profits are con- power. We are indebted to Mr. Emil S. Boas for our illustration and particulars. cerned, the invention of toys pays better than those of anything else. Money has been, and always can be, made more THE "POLYPHONE"—ATTACHMENT FOR PHONOGRAPHS.… … Sei ■?«■*& the use of two diaphragms imparts to the sound ward movement of the sleeve. that quality which, as before remarked, de- The valve is under the complete control of the oper- pends upon the application of the principle of ator, for when he grasps the sleeve to force the drill…

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