I have often asked myself the question, Why did not our Joseph Henry, who discovered the oscillatory electrical motions and operated with apparatus similar to that employed by Hertz, pursue his studies further than he did in 1842? and why did not Maxwell, the formulator of the modern electromagnetic science, perform those ideally simple experiments which Hertz performed? The knowledge of the electrical oscillator was the same in 1865 as in 1887, and Maxwell undoubtedly had that knowledge. History offers an answer to these questions and this answer throws a splendid light upon the character of these two great scientists. Soon after 1842 Joseph Henry resigned his professorship at Princeton College, and bade good-by to his laboratory where he had made several of his splendid discoveries, and where in 1832 he had constructed and operated the first electromagnetic telegraph, one of the practical results of his great discoveries. This happened long before Morse had ever been heard of. Henry’s fame among men of science was very great and promised to grow even greater if he continued his scientific researches. He was still in his prime, only a few years over forty. But a patriotic duty called him to Washington, where the Smithsonian Institution waited for his skilled hand to organize it and to defend it against the scheming politician. This duty tore him away from his beloved laboratory, and he spent the rest of his life, over thirty years, in Washington as secretary of the Smithsonian Institution, as originator of most of the national scientific bureaus of which this country is proud to-day. He was also the first president of the National Academy of Sciences, chartered by Congress in 1863, thanks to his efforts. Physical science under his leadership had rendered valuable service to the country during the Civil War, and the congressional charter to the National Academy of Sciences was a graceful recognition of this service. I have already pointed out Joseph Henry’s splendid efforts for the advancement of scientific research in this country and shall return to it later. He was a great scientist, but he was also a great patriot; his country stood first and his own scientific achievements and fame stood second in his heart. That, I am sure, was the reason why he did not pursue any further than he did his researches of electrical oscillations. I will mention here that one of the most gratifying results of my humble efforts was the naming of an electrical unit after his name. My colleague, the late Professor Francis Bacon Crocker of Columbia University, joined me most enthusiastically in these efforts; and the Electrical Congress in Chicago in 1893, at which Helmholtz presided, adopted the name Henry as the unit of electrical inductance; the unit Farad was named in honor of Faraday. No other electrical units are in more frequent use than the Farad and the Henry, particularly in the radio art. No other men