Nikola Tesla - Free-Energy Devices

492 INVENTIONS OF NIKOLA TE8LA.ends protruding from the boxes B.Assume that the motion impartedbe such as to move the piston to the left (when looking atthe diagram) then the air rushes through the slot s' and tube Tinto the chamber to the left. The pressure now drives the pietontowards the right and, owing to its inertia, it overshoots theposition of equilibrium and allows the air to rush through theslot s and tube T into the chamber to the right, while the communicationto the left hand chamber is cut off, the air of thelatter chamber escaping through the outlet o on the left. Onthe return stroke a similar operation takes place on the righthand side. This oscillation is maintained continuously and theapparatus performs vibrations from a scarcely perceptible quiveramounting to no more than l of an inch, upto vibrations of a littleover | of an inch, according to the air pressure and load. It isindeed interesting to see how an incandescent lamp is kept burningwith the apparatus showing a scarcely perceptible quiver.To perfect the mechanical part of the apparatus so that oscillationsare maintained economically was one thing, and Mr. Teslahinted in his lecture at the great difficulties he had first encounteredto accomplish this. But to produce oscillations which wouldbe of constant period was another task of no mean proportions.As already pointed out, Mr. Tesla obtains the constancy of periodin three distinct ways. Thus, he provides properly calculatedchambers, as in the case illustrated, in the oscillator itself or he associateswith the oscillator an air spring of constant resilience. But;the most interesting of all, perhaps, is the maintenance of the constancyof oscillation by the reaction of the electromagnetic part ofthe combination. Mr. Tesla winds his coils, by preference, for hightension and associates with them a condenser, making the naturalperiod of the combination fairly approximating to the average periodat which the piston would oscillate without any particular provisionbeing made for the constancy of period under varying pressureand load. As the piston with the coils is perfectly free to move,it isextremely susceptible to the influence of the natural vibrationset up in the circuits of the coils H H. The mechanical efficiencyof the apparatus is very high owing to the fact that frictionis reduced to a minimum and the weights which are moved aresmall;the output of the oscillator is therefore a very large one.Theoretically considered, when the various advantages whichMr. Tesla holds out are examined, it is surprising, consideringthe simplicity of the arrangement, that nothing was done in this