Amateur mechanics ... a book for old and young who like to make things .. (1907)
Popular mechanics magazine, Chicago. [from old catalog] · Chicago, Popular mechanics · leaf 14
sfrom the center at a velocity which is nearlyconstant, thereby producing a partial vacuumbetween the spool ami the card. Can anyof the readers of Mechanics for YoungAmerica devise a practical application ofthis contrivance? Mechanics for Young America, our iplandid book for boys. Only 25 centa.… … To Make a Telephone Sing mitter, as shown in the illustration. Theexperiment will work well on most tele-phones, but not on every one. When the receiver is placed in the posi-tion shown it acts like an ordinary buzzer,and the function of the transmitter willthen be that of an interrupter. The…
Handicraft · Amusements
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Graphophone patents] (1878)](https://img.insideoutlibrary.com/img/200/ia-graphophonepaten07unit-841-546.webp)
