A text-book of physiology, for medical students and physicians . omplete instrument, in Fig. 3!). A large l,i,i i hoe magnel <», 8) is fixed permanently and between the poles is swung a coil (c) of delicate wire, t he I wo ends of t lie u ire being connected with bindingposts in the frame of the instrument. The coil is held in place below by a,delicate piral. In Fig, 40 it- will be seen that the delicate thread suspending ELECTRICAL PHENOMENA. 99 the coil carries just above the coil a small mirror, m, and a plate of thin micaor aluminum. The mirror is deflected with the coil, and when viewe
A text-book of physiology, for medical students and physicians . omplete instrument, in Fig. 3!). A large l,i,i i hoe magnel <», 8) is fixed permanently and between the poles is swung a coil (c) of delicate wire, t he I wo ends of t lie u ire being connected with bindingposts in the frame of the instrument. The coil is held in place below by a,delicate piral. In Fig, 40 it- will be seen that the delicate thread suspending ELECTRICAL PHENOMENA. 99 the coil carries just above the coil a small mirror, m, and a plate of thin micaor aluminum. The mirror is deflected with the coil, and when viewed throughthe telescope pictured in Fig. 39 the image of the scale above the telescope isreflected in this mirror. As the coil and mirror are twisted by the actionof the current passing through the former the reflection of the scale in themirror is displaced. By means of a cross hair in the telescope the angle ofdeflection may be read upon the reflected scale. The aluminum vane back ofthe mirror makes the system dead-beat, so that when a deflection is obtained. Fig. 40.—Diagram of struc-ture of the dArsonval galvanom-eter, c is the coil of fine wirethrough which the current ispassed. It is swung by a finethread of phosphor-bronze so asto lie between and close to thepoles—in) north pole, and (s)south pole—of the magnet. Justabove the magnet the thread car-ries a mica or aluminum vane towhich is attached a small scale of the instrument is re-flected in this mirror and isobserved through the telescopeshown in Fig. 38.
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Keywords: ., bookautho, bookcentury1900, bookdecade1900, booksubjectphysiology
