New Telephone Sound Augmenter

1916 Scientific American  
IT is po�si1l1e tu cunstruct a number of novel pictures, all uf which may afford a good deal of diversion. One llWY Jir�t of all des�ribe the mysterious 11ieture, quite an old hlea, by tile way, but one which is not commonly knowll at the present time. F'or the purpose it is need ful to take two pieces of glass exactly the same size; the lllffisurements might suitably be about four inches wid(', and five or six: illehe� long. Hather thick gla�s iH l:e�t, although any kind would answer the
more » ... ld answer the purpose. Bee that the sl l f!ets are quite clean and then set about Lurderillg oue of the pieces with strips of eardboard,
doi:10.1038/scientificamerican09161916-180bsupp fatcat:laznm6l66fhzjjdx5cfvtmsdyy