Electronic Engraving

If all the human fingers and toes in the world (somewhat more than 30 billion) were free electrons and were multiplied by a billion and again by a billion, all those electrons would weigh just about one ounce avoirdupois. And yet one of those almost weightless electrons, a negative charge of electricity, as it shoots from the cathode of an X-ray tube or from the filament of a radio tube engraves its path on metal.

The paths are slim for electrons going at high speed, broader for slower moving ones. This is a phenomenon noted in Professor Floyd Karker Richtmyer's physics laboratory at Cornell University and announced last week. One of his graduate students, Dr. P. H. Carr of Gaffney, S. C., had noted how pitted the metal targets of X-ray tubes became after long electronic bambardment,* and inferred that flicking light also left its invisible mark. To bring such marks, if existent into sight meant long trials of various reagents on such battered metals. In the end he found that mercury vapor "developed" electronic engravings on gold, iodine on silver, hydrochloric acid on zinc, iodine on copper.

*In an X-ray tube the cathode shoots a stream of electrons at a hard metal target. The electrons heat up a spot of the metal so that it gives off invisible light rays, the X-rays.

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