Knight's American mechanical dictionary : a description of tools, instruments, machines, processes and engineering, history of inventions, general technological vocabulary ; and digest of mechanical appliances in science and the arts . he operating-room has two windows, through one of whichsufficient yellow light is admitted to enable the operator towork; the lower piirt of the other window is provided with ashutter 14 inches high, the upper part being blackened Inthe shutter is a hole in which is inserted a tube a, throughwhich the solar light retlected from a plane mirror b, or. prefer-ably
Knight's American mechanical dictionary : a description of tools, instruments, machines, processes and engineering, history of inventions, general technological vocabulary ; and digest of mechanical appliances in science and the arts . he operating-room has two windows, through one of whichsufficient yellow light is admitted to enable the operator towork; the lower piirt of the other window is provided with ashutter 14 inches high, the upper part being blackened Inthe shutter is a hole in which is inserted a tube a, throughwhich the solar light retlected from a plane mirror b, or. prefer-ably a helio^tat, is thrown upon the achromatic condenser ofthe microscope; the microscope c is placed on a shelf at thewindow of the dark room, and the light reflected through tlietube, which is provided with an achromatic lens of about 10inches focal length, is thrown upon the achromatic is the focusing device ; g/, the negative-holder and its powers from 2(0 to 5(Kt, a i g-inch objective without au eye-piece is u,-;ed, the power being varied by increasing or diminish-ing the distance of the sensitized plate froui the cell filled with ammonio-sulphate of copper, which absorbs Fig. 3683. Fig. 3684. Woodiear(Vs Microphotographic Apparatus {with Solar Light). the non-actinic rays, is interposed between the large lens andthe condenser, and a hood is drawn around the instrument toprevent leakage of lijrht into the room. For objects less than 500 diameters, the time ofexposure, being less than a second, is regulated by a slidingshutter placed before a slit in front of the microscope, the widthof the slit being adjusted to correspond with the required lengthof exposure. For powers between 500 and 1,500, a i,,,.-iuchobjective is employed, dispensing, in general, with an eye-pieceor amplifier, iind placing the sensitized plate a-t a distance notexceeding 3 to 4 feet from the microscope. In the case ofobjects having very minute details, however
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Keywords: ., bookcentury1800, booksubjectin, booksubjectmechanicalengineering
