898

. NVENTIONS OF NIKOLA TESLA.

nations per second to excite the induction coil for charging theLeyden jar which discharges through the primary—shown dia-gvammatically in Fig. 211,—as in such case, before the disrup-tive discharge takes place, the tube or bulb is slightly excited andthe formation of the luminous circle is decidedly facilitated.

Fig. 211.

Primaryin Lamp.

But I have also used a Wimshurst machine in some experi-ments.

Prof. J. J. Thomson’s view of the phenomena under consid-eration seems to be that they are wholly due to electro-magneticaction. I was, at one time, of the same opinion, but upon care-fully investigating the subject I was led to the conviction thatthey are more of an electrostatic nature. It must be remem-bered that in these experiments we have to deal with primarycurrents of an enormous frequency or rate of change and of highpotential, and that the secondary conductor consists of a rarefied

Fig. 212.

gas, and that under such conditions electrostatic effects must playan important part.

In support of my view I will describe a few experiments madeby me. To excite luminosity in the tube it is not absolutelynecessary that the conductor should be closed. For instance, if