Twentieth century hand-book for steam engineers and electricians, with questions and answers .. (1905)
Swingle, C. F. [from old catalog], Horstmann, Henry Charles, 1858- [from old catalog], Tousley, Victor Hugo, 1875- [from old catalog] · Chicago, F. J. Drake & co. · leaf 560
lation. Although not the best insulator by anymeans, there are few substances which possess betterinsulating qualities than air, although on account of itsabsorption of moisture, it becomes often a much poorerinsulator than many other materials. In this type of ELECTRICITY FOR ENGINEERS 141… … FIGURE 81. increased, the core moves up into the helix and causesa deflection of the pointer across the scale on theinstrument. This type of instrument has the sameobjection as that of the magnetic vane instrument, 142 ELECTRICITY FOR ENGINEERS namely, residual magnetism of the iron, and henceerror…
