Edison : his life and inventions . l. Such a record or phonogram, as it was thencalled, could be removed from the machine or re-placed at any time, many reproductions could beobtained without wearing out the record, and when-ever desired the record could be shaved off by aturning-tool so as to present a fresh surface on whicha new record could be formed, something like anancient palimpsest. A wax cylinder having wallsless than one-quarter of an inch in thickness couldbe used for receiving a large number of records, sincethe maximum depth of the record groove is hardlyever greater than one one
Edison : his life and inventions . l. Such a record or phonogram, as it was thencalled, could be removed from the machine or re-placed at any time, many reproductions could beobtained without wearing out the record, and when-ever desired the record could be shaved off by aturning-tool so as to present a fresh surface on whicha new record could be formed, something like anancient palimpsest. A wax cylinder having wallsless than one-quarter of an inch in thickness couldbe used for receiving a large number of records, sincethe maximum depth of the record groove is hardlyever greater than one one - thousandth of an on, and as the crowning achievement in thephonograph field, from a commercial point of view,came the duplication of records to the extent of manythousands from a single master.** This work wasactively developed between the years 1890 and 1898,and its dif^culties may be appreciated when theproblem is stated; the copying from a single master 218 (T) o* 3 cro•I a n< ?t w o t-H w o H w p o 1 d pi o. THE PHONOGRAPH of many millions of excessively minute sound-waveshaving a maximum width of one hundredth of aninch, and a maximum depth of one thousandth ofan inch, or less than the thickness of a sheet of tis-sue-paper. Among the interesting developments ofthis process was the coating of the original or masterrecord with a homogeneous film of gold so thin thatthree hundred thousand of these piled one on top ofthe other would present a thickness of only one inch!Another important change was in the nature of areversal of the original arrangement, the cylinder ormandrel carrying the record being mounted in fixedbearings, and the recording or reproducing devicebeing fed lengthwise, like the cutting-tool of a lathe,as the blank or record was rotated. It was earlyrecognized that a single needle for forming the recordand the reproduction therefrom was an undesirablearrangement, since the formation of the record re-quired a very sharp cutting-tool, while sati
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Keywords: ., bookauthormartinth, bookcentury1900, bookdecade1910, bookyear1910
