This photograph demonstrates the exceedingly fine particle size of Ludox colloidal silica, a new product of the DuPont Company. This picture was taken with an electron microscope. The magnification is 25,000 diameters. This high magnification was...
Typed caption: "This is inside the tunnel under Seymour Narrows which extended about 2,400 feet from Maud Island to a point under Ripple Rock, a massive underwater mountain. This age-old peril to navigation was destroyed on April 5, 1958, by the...