Bullivant, Cecil Henry · New York, Dodge publishing company · leaf 415
HOW TO MAKE A TELEPHONE 407 The thin plate which vibrates with the voice must next be made. Obtain a smooth piece of very thin sheet-iron — of just such a texture S-i3*1 A Fig. 3. — Section of completed Fig. 2. -Arrangement of instrument. magnet. as is used by photographers for ferrotypes. Take the… … Fig. 4. — Connection with battery. section. Take the lid in which you have already cut the circular hole and fasten it to the box in such a way that it keeps the iron plate in position (Q, Fig. 3). Push the magnet very close to, but not quite touching, the disc of
Amusements
Internet Archive · The Library of Congress · Public domain (published before 1931). Free to use for anything.
