Twentieth century handbook for steam engineers and electricians, with questions and answers; a practical nontechnical treatise on the care and management of steam engines, boilers and electric machinery (1922)
Swingle, Calvin Franklin, 1846- [from old catalog] · Chicago, F. J. Drake & company · leaf 1465
tion.—If a piece of zinc, and a piece of copperbe placed in a jar containing dilute sulphuric acid, andnot allowed to touch each other below the surface of theliquid, but are connected above it, by a wire, a current ofelectricity will flow through the wire, and the wire will showmagnetic qualities.… … NEGATIVEPOl£ ORELECTRO on PLATE
