Twentieth century hand-book for steam engineers and electricians with questions and answers; a practical non-technical treatise .. (1913)
Swingle, Calvin Franklin, 1846- [from old catalog] · Chicago, F. J. Drake & company · leaf 1341
Fig. 614switch board instrument a certain spot and stop dead. This is called a ^^dead beat^needle. Some instruments have electro-magnets instead of per-manent magnets. The Thomson Astatic instruments areof this type. Two of these instruments are shown in Figs.615 and 616. This latter has a scale or… … Fig. 615switch boakd ammeter
