Typescript letter written on the Offices of Charles H. Riches letterhead and signed by Charles H. Riches. In this letter, Riches responds to F. Lorne Hutchison's request that he study Zuelzer's United States patent No. 1,027,790. Details the differences, with specific reference to the text of the patent application, between Zuelzer's patent and those held by the Board of Governors of the University of Toronto.
