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 62
i ; : :, tloere are sev-eral other : ; the mercurycommutator types,me better known tn: _::e ex-pi denced in coil operation. Automatic Time Switch This device can be used to either open or close the circuit at any desired time. An alarm clock is nrmlv fast- a wooden bracket and provided ?mall wood… … Will Open or Clos-e Circuit as D«sired POPULAR MECHANICS When the cord is passed oyer pulleyshown in Rg. 1. the circuit will be closed when the alarm goes off, but patted over I» the circuit willnea. Pullej I is fastened to aof spring Bteel, E, which in op-eration i- bent, aa shown by the…
Handicraft · Amusements
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer03inte-706-409.webp)