To determine the degree of gloss in a lacquer or finish, du Pont chemists use a device that measures the amount of light reflected. The light from a constant source is thrown back from the panel into the telescope tube. One half of the 'eyepiece'...
Parades & processions; Soldiers; Military organizations; Military officers
Letter from R. Emmet Robinson informing du Pont of a torch light procession that was being organized to welcome home the 4th Regiment of Delaware Volunteer Infantry. According to Robinson, the procession was also intended to affect an upcoming...
Artillery (Troops); Artillery (Weaponry); Campaigns & battles; Soldiers; Military officers
Narrative of the military campaigns that Light Battery B, 5th U. S. Artillery participated in during 1864, including the campaigns in Virginia's Shenandoah Valley. This work also lists the men who served in the battery. This copy is an expanded...
An unusual property of Lucite acrylic resin is its ability to pipe light efficiently and with very little leakage around curves (radius of the curve must be at least twice the diameter of the thickness of the rod or sheet used). This ability is...
Lamp end of the absorption system of the ultra violet photometer shows a mercury lamp with glass envelope removed. Radiation from the lamp is rendered roughly parallel by condensing lenses of quartz and the light is reflected down the absorption...
Text from back of image: "The first International Challenge Tour for Light Planes, the biggest light plane contest ever held, started from Orly, near Paris yesterday (Wed). After preliminary tests for folding, weight, engine-starting, etc., the...
Text from back of image: "The first International Challenge Tour for Light Planes, the biggest light plane contest ever held, started from Orly, near Paris yesterday (Wed). After preliminary tests for folding, weight, engine-starting, etc., the...
Handwritten on back: "Lower Flower Garden, Square pond; Light limestone walk; ivory white pansies around pond; jar - ivory white. steps and platform - dark red brick; approach to steps is same as walk; stone work in pond - dark ones are dark gray;...
Table of Contents: The Layfayette Centenary; Another Ute trail is rejuvenated; Fast and fugitive colors; Keep the cobwebs off your guns; Better light, better sight; Paint for better light; Carrying a river across mountains and deserts; Some unusual...
New type sleeper trailer of light weight stainless steel construction for travel in Syrian desert. Constructed by the Edward G. Budd Company of Philadelphia for the Nairn Transport Company Ltd. The trailer utilizes the same principles of...
New type sleeper trailer of light weight stainless steel construction for travel in Syrian desert. Constructed by the Edward G. Budd Company of Philadelphia for the Nairn Transport Company Ltd. The trailer utilizes the same principles of...
Correspondence regarding a draft against the "George Hallett" shipment, bills of lading for "Scargo" and "John Haven," and the "Northern Light" shipment. Includes memos of invoices, refractions of shipments, refractions of purchase, and of...
Final inspection of Dycril printing plates under gold light at DuPont's new plant at Parlin, New Jersey. Operator here inspects plate to insure against surface flaws. When used in printing, the photosensitive plate is placed in contact with a...
Final inspection of Dycril printing plates under gold light at DuPont's new plant at Parlin, New Jersey. Operator here inspects plate to insure against surface flaws. When used in printing, the photosensitive plate is placed in contact with a...
Inspections station of type used to inspect Photolith and X-ray film after film has been slit and chopped. Girl inspects film for flaws ad proper size, viewing it in reflected light form safe light.
A new type of outdoor sign originally conceived by engineers of the Sun Oil Company mounted next to a conventional sign illustrates elimination of glare from projecting lamps. The new sign on the right is illuminated from within by cold cathode...
