. The elements of physiological physics: an outline of the elementary facts, principles, and methods of physics; and their applications in physiology. Biophysics. TOO PHYSIOLOGICAL PHYSICS. [ sensitive instrument, Laving as many as 30,000 coils of fine wire. The form of instrument mainly used now is the reflecting galvanometer, of which two forms will be described, that of Sir William Thomson, largely employed in this country, and one of a German origin, called Wiedemann's galvanometer. The feature of Sir William Thomson's instrument (Fig. 53) is the small size of the needles, so that t
. The elements of physiological physics: an outline of the elementary facts, principles, and methods of physics; and their applications in physiology. Biophysics. TOO PHYSIOLOGICAL PHYSICS. [ sensitive instrument, Laving as many as 30,000 coils of fine wire. The form of instrument mainly used now is the reflecting galvanometer, of which two forms will be described, that of Sir William Thomson, largely employed in this country, and one of a German origin, called Wiedemann's galvanometer. The feature of Sir William Thomson's instrument (Fig. 53) is the small size of the needles, so that they possess little weight, with a high degree of magnetisa- tion. The magnets are very thin, usually not more than one-eighth of an inch long, and are arranged in two sets, an upper and a lower, connected together by an aluminium rod. The needles of each set are arranged astatically. Round each set is a separate coil of wire, the lower coil (6, Fig. 53) having its course in opposite direction to the upper. The coils are brought very near to the needles, and con- tain a very large number of turns of fine wire. Fixed to the upper set of needles is a slightly concave Fig. 53.—Sir Wm. mirror, not more than one quarter Thomson'sReflect- r> i v j_ rrn ing Galvanometer, of an inch in diameter. Hie system of needles and mirror is so light as to weigh barely a grain. The system is suspended by a single fibre of fine silk from a brass pin fixed on the top of the vulcanite frame of the coils. The coils are supported on brass uprights. The whole apparatus stands on a vulcanite disc, brass-bound, and levelled by three screws, and is enclosed in a brass-bound glass shade. The cover of this shade is of brass, and supports a brass rod c, on which slides a large curved magnet d, feebly magnetised, by which an artificial meridian can be created in any. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and
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Keywords: ., bookcentury1800, bookdecade1880, bookpublisherphila, bookyear1884
