Micro-Bible

At first glance, the tiny exhibit at the National Cash Register Co.'s pavilion at the New York World's Fair seems singularly insignificant. But the sheet of transparent plastic, less than 2 in. square, is covered closely with 1,240 barely visible rectangles. And when examined with a microscope, each tiny rectangle spreads out into a page of the Bible. Both the Old and New Testament -- all 773,746 words of the King James Version -- are all clearly recorded on that one slip of plastic. The job took only four hours.

The Bible was reproduced by what Bob Chollar, the company's head of research, calls photochromic micro images, or PCMI. The film has none of the silver halide grains that are the vital element in conventional photographic film; instead there is a very thin layer of a dye that darkens rapidly when exposed to ultraviolet light. The resulting picture has no "grain." Images of Bible pages projected in ultraviolet were reduced by lenses and focused one by one on the dye. After each exposure the film was moved mechanically to array the tiny pages in close-packed rows. This miracle of miniaturization, which makes the traditional Lord's Prayer engraved on a pinhead seem downright brobdingnagian, can cram 1,000,000 book pages on a stack of 3-in. by 5-in. index cards about 4 in. high. It could pack all the books in the Library of Congress into six ordinary filing cabinets. To read one of these literary slides, a viewer can use a device similar to a microscope, or the material can be projected in standard page-size on a translucent screen.

While hailing the miniaturizing ability of PCMI, the company's scientists think it has another talent that is even more important. Records made by ultraviolet light are easily correctable. When the recording operator or one of his machines makes an inevitable mistake, the unwanted page can be erased by one quick flash of yellow light. A new page can be printed by ultraviolet in the same place. The observer can watch both erasure and printing in green light, which does not affect the sensitive dye.

When the card is finally complete, with all its million pages of print in the desired places, it can be made permanent by a secret process that makes it insensitive to light of any color.

This file is automatically generated by a robot program, so reader's discretion is required.