. The medical and surgical uses of electricity. . nfluence machine datesfrom i860, when C. F. Varley produced a form with six carriers mountedon a rotating disk of glass. This was followed in 1865 by the machine H ELECTRO-PHYSICS. of Holt and that of Topler, and in 1867 by those of Kelvin, Then fol-lowed the Wimshurst machines, perhaps the most widely used of all. Wimshiirsfs Influence Machine.—We have in this machine no fixed fieldplates. In its simplest form it consists (Fig. 10) of two circular plates ofvarnished glass, which are geared to rotate in opposite directions. What occurs in this
. The medical and surgical uses of electricity. . nfluence machine datesfrom i860, when C. F. Varley produced a form with six carriers mountedon a rotating disk of glass. This was followed in 1865 by the machine H ELECTRO-PHYSICS. of Holt and that of Topler, and in 1867 by those of Kelvin, Then fol-lowed the Wimshurst machines, perhaps the most widely used of all. Wimshiirsfs Influence Machine.—We have in this machine no fixed fieldplates. In its simplest form it consists (Fig. 10) of two circular plates ofvarnished glass, which are geared to rotate in opposite directions. What occurs in this machine is best explained by means of a diagram(Fig. 11). In order to render the explanation clearer, the rotating platesare represented as though they were two cylinders of glass, rotating inopposite ways, one inside the other. The inner cylinder will representthe front plate, the outer the back plate. In Figs. 10 and 11 the front plate rotates right-handedly, the backplate left-handedly. The neutralizing brushes, w,, n^, touch the front sec-. FlG. 10. tors, while «,„ n^ touch against the back sectors. Now suppose any oneof the back sectors represented near the top of the diagram to receive aslight positive charge. As it moves onward toward the left it will comeopposite the place where one of the front sectors is moving past thebrush n^. The result will be that the sector so touched while under in-fluence by w, will acquire a slight negative charge, which it will carry on-ward toward the right. When this negatively charged front sector arrivesat a point opposite w^, it acts inductively on the back sector, which is be-ing touched by «,,; hence this back sector will in turn acquire a positivecharge, which it will carry over to the left. In this way all the sectorswill become more and more highly charged, the front sectors carrying overnegative charges from left to right, and the back sectors carrying over GOLD-LEAF ELECTROSCOPE. 15 positive charges from right to left. At t
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishernewyo, bookyear1896
