Elementary telegraphy : a manual for students; written specially to meet the requirements of the ordinary grade of the subject as published in the syllabus of the city and guilds of London Institute (1910)
Pendry, H. W. (Henry Walter) · London ; New York : Whittaker & Co. · leaf 101
- consists of twoflat coils of wire and two magnetic needles so pivoted thattheymove horizontally one AAatliin and the other aboA^e thecoiis. The poles of the needles are dissimilarly placed,that is, A^ above S, and rice versa, and by this means the … Fin, 71.—Astatie galvanometer. directive force of the earths magnetism is practicallyeliminated, consequently tJie needles can respond veryeasily to the effect of a current. Sometimes they aresuspended by a thin AA^ire or silk fibre instead of beingpivoted. The greatest defect of the astatic…
Telegraph
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
