Electricity for public schools and colleges . Fig. Fig. ii. of any plug throws into the circuit that resistance coil which inthe figure lies below that plug. Hence, by a suitable removal ofplugs we can throw into the circuit any resistance that is con-tained in the box. The figure indicates that the coils are so wound as to obviateerrors due to induction {see Chapter XXI.). 224 ELECTRICITY CH. XIV. § 3. Wheatstones Rheostat—We will now mention an instru-ment intended for the measurement of resistances continuously,the resistance box above described being evidently discontinuous. J^ote. We
Electricity for public schools and colleges . Fig. Fig. ii. of any plug throws into the circuit that resistance coil which inthe figure lies below that plug. Hence, by a suitable removal ofplugs we can throw into the circuit any resistance that is con-tained in the box. The figure indicates that the coils are so wound as to obviateerrors due to induction {see Chapter XXI.). 224 ELECTRICITY CH. XIV. § 3. Wheatstones Rheostat—We will now mention an instru-ment intended for the measurement of resistances continuously,the resistance box above described being evidently discontinuous. J^ote. We may here remark that on account of certain defects of contact, &c., that appear to be inherent in the very nature of a Wheatstones rheostat,this instrument cannot be used in any but very rough measurements. Its chief use is as a continuously adjustable resistance, in cases where it isnot desired to measure the resistance thus introduced. A and B are two parallel cylinders, A being of brass and B ofwood. A line uniform wire can be wound from A
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Keywords: ., bookcentury1800, bookdecade1890, bookpubl, booksubjectelectricity
