6 DECEMBER 1884, Page 20

Oa the Alterations in the Electrical Resistances of Metallic Wires

Produced by Coiling and Uncoiling. By James Hopps.—This paper, originally read before the Physical Society, and now reprinted from the Philosophical Magazine, deserves some attention. Mr. Hopps observed in the workshops of Cooper's Hill College that great differ- ences often existed between the resistance of the wire of resistance- coils before it was coiled on its bobbin and after, and was led to make a series of interesting experiments on these differences as they were exhibited by various metals. The results are carefully stated, and illustrated by tables, in these pages.