OCR Text |
Show New Powerful Microscope Uses Beam of Electrons A new kind of microscope is so powerful that it shows particles too small to be seen by optical methods. Secret of the new instrument in-strument is the use of a beam of electrons instead of a beam of light, and by this means even the shape of particles of smoke can be clearly seen. Zinc oxide smoke is shown to consist of long thin needles; magnesium mag-nesium oxide smoke of groups of small cubic crystals; while carbon car-bon smoke from a wax taper consists con-sists of very small units forming long chain groups. - The instrument, the electron microscope, mi-croscope, was designed by Prof. L. C. Martin, Imperial College of Science, London. The "lenses" of the electron microscope mi-croscope consist of electrostatic and magnetic fields which refract the electron beams in much the same way that the glass lenses refract the light in an optical instrument. in-strument. By the use of magnetic coils an enlarged image of a small object can be reproduced on a fluorescent flu-orescent screen, or photographed. |