Science: Micromicrocamera

One of the questions medieval debaters liked to argue was how many angels could dance on the head of a pin. The National Bureau of Standards does not allow itself to measure angels—but it has developed a micromicrocamera that can put a page of the Bible on a bit of photographic film much smaller than a pinhead. On this scale all the pages of a Bible would barely cover Lincoln’s head on a if piece; the 27,357 pages of the Encyclopaedia Britannica could be reproduced on the back of a matchbook.

The camera that performs these stunts is a sort of microscope in reverse. One end looks at a page of print or a pattern of parallel lines, and the train of small lenses at the other end forms an exact and tiny image. Individual letters on the negative are hardly bigger than bacteria, and an excellent microscope is needed to read them.

Developed by Calvin S. McCamy, chief of the bureau’s photographic research section, the camera’s purpose is to test the resolving power (fine-grainedness) of photographic films, plates and papers. It may never be used for practical microfilming. It is too hard to focus, and it must be shielded from even faint vibration by enclosing it and the object to be photographed in a heavy metal cylinder suspended by springs. If a stray speck of dust wanders onto the film it might blot out half a book.