CHAPTER XLII.

Mr. Tesla’s Personal Exhibit at the World’s Fair.

While the exhibits of firms engaged in the manufacture ofelectrical apparatus of every description at the Chicago World’sFair, afforded the visitor ample opportunity for gaining an ex-cellent knowledge of the state of the art, there were also numbersof exhibits which brought out in strong relief the work of theindividual inventor, which lies at the foundation of much, if notall, industrial or mechanical achievement. Prominent amongsuch personal exhibits was that of Mr. Tesla, whose apparatusoccupied part of the space of the Westinghouse Company, inElectricity Building.

This apparatus represented the results of work and thoughtcovering a period of ten years. It embraced a large number ofdifferent alternating motors and Mr. Tesla’s earlier high fre-quency apparatus. The motor exhibit consisted of a variety offields and armatures for two, three and multiphase circuits, andgave a fair idea of the gradual evolution of the fundamental ideaof the rotating magnetic field. The high frequency exhibit in-cluded Mr. Tesla’s earlier machines and disruptive discharge coilsand high frequency transformers, which he used in his investi-gations and some of which are referred to in his papers printedin this volume.

Fig. 297 shows a view' of part of the exhibits containing themotor apparatus. Among these is showm at a a large ring in-tended to exhibit the phenomena of the rotating magnetic field.The field produced was very powerful and exhibited strikingeffects, revolving copper balls and eggs and bodies of variousshapes at considerable distances and at great speeds. This ringwas wound for two-pliase circuits, and the winding was so dis-tributed that a practically uniform field was obtained. This ringwas prepared for Mr. Tesla’s exhibit by Mr. C. F. Scott, elec-trician of the Westinghouse Electric and Manufacturing Com-pany.

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