Nikola Tesla - Free-Energy Devices

278 INVENTIONS OF NIKOLA TESLA.pump settles down. Ifthis course is not followed, the sticks, asordinarily employed, may give off moisture at a certain veryslow rate, and the pump may work for many hours withoutreaching a very high vacuum. The potash was heated either hya spirit lamp or by passing a discharge through or it, by passinga current through a wire contained in The it. advantage in thelatter case was that the heating couldjbe more rapidly repeated.Generally the process of exhaustion was the following At:the start, the stop-cocks c and c t being open, and all other connectionsclosed, the reservoir n> was raised so far that the mercuryfilled the reservoir R tand a part of the narrow connectingU-shaped tube. When the pump^was set to work, the mercurywould, of course, quickly rise in the tube, and reservoir RJ waslowered, the experimenter keeping ^the mercury at about thesame level. The reservoir RJ wasj balanced by a long springwhich facilitated the operation, and the friction of the parts wasWhen thegenerally sufficient to keep it in almost any position.Sprengel pump had done its work, the'reservoir R% was further loweredand the mercury descended in R and tilledtR>, whereupon stopcock02 was closed. The air adhering to the walls of R and thattabsorbed by the mercury was carried off, and to free the mercuryof all air the reservoir E 2was for a long time worked up anddown. During this process some air, which would gather belowstopcock c 2 was, expelled from R 2 by lowering it far enough andopening the stopcock, closing the latter again before raising thereservoir. When all the air had been expelled from the mercury,and no air would gather in Rg when it was lowered, the causticpotash was resorted to. The reservoir RJ was now again raiseduntil the mercury in RJ stood above stopcock Ci. The causticpotash was fused and boiled, and moisture 'partly carried off bythe pump and partly re-absorbed and this ; process of heatingand cooling was repeated many times, and each time, upon themoisture being absorbed or carried off, the reservoir B^ was fora long time raised and lowered. In this manner all the moisturewas carried off from the mercury, and both the reservoirs werein proper condition to be used. The reservoir R 2was then againraised to the top, and the pump was kept working for a longtime. When the highest vacuum obtainable with the pump hadbeen reached, the potash bulb was usually wrapped with cottonwhich was sprinkled with ether so as to keep the potash at avery low temperature, then the reservoir R 2was lowered, and uponreservoir R tbeing emptied the receiver was]quickly sealed up.