In 1925, C. Francis Jenkins—holder of over three hundred patents and builder of an early motion-picture projector—published a survey of technologies for sending pictures by wire and radio. The book is not a theoretical treatise but a working inventor’s scrapbook of machines, patents, and firsthand accounts. Jenkins describes the telestereograph used by the London Daily Mirror in 1909, the Korn machine that transmitted halftones between London and Paris in 1907, and his own early suggestion (which he later called “the bravery of ignorance”) of a surface studded with thousands of selenium cells. The catalog subject is simply “Phototelegraphy,” but the excerpts show a text preoccupied with the messy, empirical process of making those systems work.

Machines as Characters

The book treats each transmission apparatus almost as a protagonist. The Baker machine, or “telestereograph,” used a halftone photograph printed in fish glue on lead foil, wrapped on a sending cylinder that rotated once every two seconds. The receiving cylinder carried absorbent paper soaked in a colorless solution that turned black when decomposed by the incoming current. Jenkins notes that the electrolytic solution was probably sodium iodide or potassium bromide, but the original report did not specify. The Dr. Korn machine, by contrast, employed a Nernst lamp and selenium cells on a Wheatstone bridge to overcome the lag of selenium. Its receiver used two fine silver strings that moved laterally in a magnetic field, widening or thinning the photographed line. Jenkins quotes Baker’s 1910 Smithsonian Report to describe how the developed film, laid out flat, resolved a spiral line into parallel lines. The Belinograph and Rignoux–Fournier scheme each get similar treatment: a paragraph of mechanical detail, a note on who built it and when, and a quiet judgment of practicality.

The Inventor’s Own Role

Jenkins does not present himself as a neutral chronicler. He dedicates the book to six young assistants who “so efficiently assisted in the attainment of Photographs by Radio, Radio Vision, and Radio Photograms.” In the foreword he compares the development of radio pictures to the evolution of motion pictures, which he helped shape: the spiral picture disc, the picture “thumb book,” cards on drums, and finally the long film strip. He admits that his own 1894 suggestion of a selenium-cell array—360,000 cells for a one-foot-square picture—was made “in the bravery of ignorance.” The biographical sketch at the front lists his inventions (the all-paper container, the first photographs by radio) and his memberships, but the excerpts show a man who is both proud of his patents and willing to call earlier ideas impractical. The text is as much a personal record as a technical one.

Evidence from Patents and Exhibitions

Jenkins grounds his descriptions in documentary sources. The Baker machine account comes from the Smithsonian Report of 1910; the Korn machine description also cites that report. The Rignoux–Fournier scheme is illustrated “by courtesy of Science and Invention.” Jenkins notes that the original picture for the “Electrograph” was given to him by T. A. Witherspoon, a principal examiner in the U.S. Patent Office who had charge of the Patent Office exhibit at the 1900 Buffalo Exposition. He adds that twenty-four years later, the American Telephone and Telegraph Company sent their first wire pictures from Cleveland—a coincidence he calls “of passing interest.” These citations do more than verify facts; they reveal a network of patent examiners, expositions, and technical journals that formed the infrastructure of early phototelegraphy. The book itself is a node in that network.

Readers should approach Vision by Radio as a primary document from the experimental phase of picture transmission, not as a finished history. Jenkins’s voice is that of a practitioner who knows the difference between a promising scheme and a workable machine. The excerpts do not reveal whether his own radio-vision system succeeded or failed, but they do show how he thought about the problem: as a series of mechanical and chemical puzzles to be solved by trial, error, and public demonstration. The book rewards attention to its small details—the fish glue, the silver strings, the “well calibrated clocks”—that later accounts often smooth over.