CHAPTER XXV.

Introduction.—The Scope of the Tesda Lectures.

Before proceeding to study the three Tesla lectures herepresented, the reader may find it of some assistance to have hisattention directed to the main points of interest and significancetherein. The first of these lectures was delivered in Xew York,at Columbia College, before the American Institute of ElectricalEngineers, May 20,1891. The urgent desire expressed immedi-ately from all parts of Europe for an opportunity to witness thebrilliant and unusual experiments with which the lecture wasaccompanied, induced Mr. Tesla to go to England early in 1892,when he appeared before the Institution of Electrical Engineers,and a day later, by special request, before the Royal Institution.Ilis reception was of the most enthusiastic and flattering nature onboth occasions. He then went, by invitation, to France, and re-peated his novel demonstrations before the Societe Internationaledes Electriciens, and the Societe Frangaise de Physique. Mr. Teslareturned to America in the fall of 1892, and in February, 1893, de-livered his third lecture before the Franklin Institute of Philadel-phia, in fulfilment of a long standing promise to Prof. Houston.The following week, at the request of President James I. Ayer,of the .National Electric Light Association, the same lecture wasre-delivered in St. Louis. It had been intended to limit the in-vitations to members, but the appeals from residents in the citywere so numerous and pressing that it became necessary to securea very large hall. Hence it came about that the lecture waslistened to by an audience of over 5,000 people, and was in someparts of a more popular nature than either of its predecessors.Despite this concession to the need of the hour and occasion, Mr.Tesla did not hesitate to show many new and brilliant experi-ments, and to advance the frontier of discovery far beyond anypoint he had theretofore marked publicly.

We may now proceed to a running review of the lectures them-selves. The ground covered by them is so vast that only the