Electrical Review, December 29, 1897, page 316:
Commercial Wireless Telegraphy.
The United States Electrical Supply Company, of 120 Liberty street, New York city, are about to introduce an apparatus for wireless telegraphy. The construction of the instrument in many ways is similar to that employed by Marconi in his experiments, by which, by the use of the Hertzian waves, a message can be transmitted through almost any obstruction.
Mr. W. J. Clarke, general manager of the company, gave a very successful exhibition of the uses of the instrument before the American Institute of Electrical Engineers on December 15. He showed in the experiment that a message could be accurately transmitted from one room to another through two closed doors.
He has done away with the reflectors used by Marconi for his air circuits, holding that they have no material influence in the transmission of the electrical current.
Mr. Clarke also claims that by means of the improvements made the new machine over that of Marconi's, a message can be accurately sent to the distance of 10 miles.
Several changes have been made in the instruments with the view of condensing them into such a shape as may be more convenient for commercial purposes.