The practical telephone handbook and guide to the telephonic exchange (1906)
Poole, Joseph · New York, Macmillan Co. · leaf 61
ction being made byan insulated copper wire passing through the liquid. The jaris rilled three parts full with a saturated solution of sulphate ofcopper, to which extra crystals are added. Over this a weaksolution of sulphate of zinc is very carefully poured so as notto mix. In the zinc solution a… … Fig. 21 sulphate of copper solution, and sinks to the bottom, and thedisplaced copper solution deposits copper on the zinc. Someof the top liquid should, therefore, be taken out every few daysby means of a syringe, and water added to take its place.A hydrometer (an instrument used to show or…
Telephone
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