Tyndall, John, 1820-1893 · London : Longmans, Green · leaf 230
C is a cylinder of brass having a spiral groove or screwcut upon its surface from end to end. It is mounted uponp spindle (well seen in fig. 109), whose length is rather morethan three times that of the cylinder. At one end of thespindle is a winch handle, between which and the cylfnder THE… … a screw is cut of the sauie pitch as that upon the cylinder—viz. eight threads to the inch. The spindle turns intwo brass bearings, one of which has an inside screwcorresponding to the screw upon the spindle. A very thin sheet-iron diaphragm d d (fig. 110) receivesthe operators voice. It is secuied…
Sound
Internet Archive · Boston Library Consortium · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer01inte-494-198.webp)
