Patent attorneys continually refer to “one skilled in the art.” Somehow, this has an antique flavor. It smacks of wrinkles, recipes, and secret formulae, rather than of the firm basis we imagine must underlie our technological civilization. One would think of art, perhaps, in the case of the physician, who deals with a system as complicated and as little understood as the human body, but scarcely in connection with a matter of applied physics, involving old and well known phenomena of great commercial importance. A particular example should, however, convince the most skeptical that there is sometimes art where one would wish and hope for science. Lest it be too discouraging, the story that follows has, I believe, a happy ending, for it looks as if the physicists and chemists are at last reaching indisputable conclusions concerning the functioning of the oxide‐coated thermionic cathode.

You do not currently have access to this content.