This folder contains correspondence from inventors and others asking for Edison's advice on technical matters or his assistance in improving or promoting inventions. Also included are general inquiries relating to the invention and patenting processes or requesting financial support for an invention. Most of the correspondence consists of unsolicited letters from the general public, and some are by children. However, there are also letters to and from Edison associates such as John W. Lieb of the New York Edison Co. Some of the correspondence for 1918 deals with antisubmarine warfare and other war-related topics, including letters to Lieb about smoke suppression in ships and George O. Smith of the U.S. Geological Survey about acoustic range finding. Also included are letters about sound recording and reproduction, electrical products, automobiles, and perpetual motion machines.

Among the inquiries that received personal attention from Edison are letters from laborer C. J. Barclay on absorbent fabric; attorney Frederick A. Hubbard on a lightning rod for the Second Congregational Church in Greenwich, Connecticut; P. J. McMahon of Key West Naval Station on a chemical motor for torpedoes; William F. McNabb of the Vanadium Metals Co. on the solubility of carbon; chemical engineer James B. Pratt on incendiary shells; businessman and author Alexander St. Clair-Abrams on a lawsuit involving an alternating-current transformer malfunction; U.S. Army engineer Henry W. Wilson on seismic instruments; and inventor Ruben Zertuche on the extraction of rubber from plants. There is also a letter regarding a possible visit to the West Orange laboratory by drill inventor Aaron Hill.

Approximately 5 percent of the documents have been selected. The unselected material includes items receiving no answer or form-letter responses stating that Edison did not become involved in others' inventions or that he was away and not reading his mail. Some of the unselected inquiries were referred by Edison's secretaries to the U.S. War Department or other government offices, while others received a brief informational reply from Edison's personal assistant, William H. Meadowcroft. Some technical suggestions were evaluated and rejected by chief engineer John P. Constable, and some foreign-language letters were redirected to the Export Division for translation. Also unselected are letters attempting to reach Edison through his wife Mina Miller Edison, inquiries regarding a news story about generating water power from small streams, and printed documents submitted by correspondents in support of their requests.

Similar letters about war-related inventions can be found in the Naval Consulting Board and Wartime Research Papers, Special Collections Series.