Science: Seeing by Electron Waves

Four years ago the first modern electron microscope was exhibited by the Siemens & Halske A.-G., in Berlin (TIME, June 6, 1938). Two years ago the R.C.A. Laboratories completed the first commercial American model, seven feet tall, magnifying by 25.000 diameters and costing $10,000. Last week R.C.A. and General Electric, racing for 1) a major public service, 2) a big market among hospitals, universities and industrial laboratories, both announced simplified, portable models at about $2,000 ready for general use—by priority customers. A big world beyond the limits of the ordinary light microscope now lies open to exploration.

A crowd of researchers from the National Exposition of Chemical Industries at Chicago witnessed the demonstrations. They compared photographs already made with the large instrument, revealing unsuspected details in the structure of metals, pigments, powder, oils and in the anatomy of bacteria and viruses. Physicians were especially eager: some expect the conquest of diseases like the common cold, influenza and infantile paralysis, caused by viruses invisible except in the electron microscope.

Greater magnification is possible because electron waves are shorter than light waves. Highest magnification requires shortest possible electron waves, hence higher voltage. The portable models sacrifice extreme magnification, but R.C.A. gives 5,000 diameters, G.E. 10,000 (compared to 2,000 useful upper limit in the best microscopes using light waves). Both can be “blown up” photographically to give in effect 100,000 diameters or more. The G.E. instrument, developed by Dr. Simon Ramo and Dr. Charles H. Bachman, has a horizontal system, is 52 inches high, operates on a 110-volt light circuit, The R.C.A. model, only 16 inches long in us optical parts, is the product of work directed by famed television expert, Vladimir Kosma Zworykin.

What the electron microscope contributes to war research will not be published. But so great an advance is expected that a society of electron microscopists is now contemplated.