Publisher's Synopsis
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1890 edition. Excerpt: ...with vulcanite discs, by Bleekrode. One of the plates of this machine may be rendered quiescent by removing the neutralizing rod. A new kind of neutralizing rod was devised by Bleekrode, having gas flames instead of combs for collecting the electricity from the surface of the rotating disc. Gas burners, consisting of pieces of bent glass tubes, were fixed on the end of a transverse wooden rod occupying the same position as the ordinary neutralizing rod in front of the rotating disc. Gas is supplied to the burners by flexible tubes, and the flames are put in conducting communication by a metallic wire, the ends of which dip in the respective gas flames. These flames behave as if they were positively electrified, the flame opposite the negative field plate is attracted, while that opposite the positive field plate is repelled. Such a neutralizing rod furnishes a useful method of visibly showing the direction of the electric current in the neutralizing rod. It is evident that the machine will not work if the wire is removed. If the vulcanite should deteriorate by the action of light or ozone it may be restored by washing with a solution of carbonate of magnesia. Machines with Multiple Field Plates.--In machines hitherto described there have usually been two field plates. In one of Holtz's earliest machines we have seen that he suggested the use of more than one pair of field plates, when it was desired to get larger quantities of electricity from a machine. Poggendorff also devised a machine, Fig.. 54, in which there were four field plates, four openings in the fixed disc, and four collecting combs standing opposite the field plates in front of the rotating disc. In such a machine, going round the disc the field plates have alternately...
