Eudiometer. A graduated glass tube, fitted with platinum 



electrodes, used in analysis of explosive gas mixtures. 

 Evaporimeter or Evaporpmeter. An instrument for ascertaining 



the quantity of a liquid evaporated in a given time. An 



atmometer. [6, 13, 17, 18,.} 

 Evaporimeter, Piche's. Consists of a graduated glass tube which 



is filled with the liquid and closed by a piece of filter or 



blotting paper. 

 Evaporimeter, Pickering's. Consists of a copper reservoir and 



a linen evaporating surface 50 sq. cm. in area. The volume 



of liquid evaporated is measured by a graduated glass tube. 

 Evelyn Bubble Clinometer. See Clinometer. [13, 15.] 

 Everest Theodolite. See Theodolite. [2, 13, 20, 21, 25, 26, 27.] 

 Evershed Spectroscope. See Spectroscope. [2, 14, 26.] 

 Ewing Compression Extensometer. See Extensometer. [4.] 

 Ewing Extensometer. See Extensometer. [4.] 

 Ewing's Apparatus. An apparatus for experiments on the 



bending of bars and for cantilever experiments. [19.] 

 Extension-Measuring Apparatus. An instrument for measuring 



minute extensions, deflections, and compressions by means 



of a multiplying optical apparatus. See also Extensometer. 



[19.] 

 Extensometer. An instrument for measuring the extension of a 



body ; especially for measuring the elongation of bars of 



iron, steel, or other metal or material subjected to a tensile 



force. [3, 4, 8, 19.] 

 Extensometer, Cambridge. An extensometer hi which the 



extension of the test piece is measured by a micrometer 



screw and a modified form of contact measurement. [4.] $ 

 Extensometer, Dr. Morrow's Mirror. An extensometer in which 



the extension is measured by the deflection of a beam of 



light reflected from a mirror connected to two parts of the 



test piece. [3, 20.] 

 Extensometer, Ewing. An extensometer, designed by Sir J. A. 



Ewing, in which the extension of the test piece is measured 



by means of a microscope with an eyepiece micrometer. [4.] 

 Extensometer, Ewing Compression. An instrument for measuring 



the elastic compression of short blocks ; constructed on 



similar principles to the Ewing Extensometer. [4.] 

 Eyeglass. Any form of lens for aiding and correcting vision, 



such as spectacles, a monocle, a pince-nez. [2, 3, 9, 13, 14, 



17, 21.] 

 Eyeglasses, Frameless. A single or double eyeglass made 



without a rim or frame. [2, 9, 15, 17, 20, 21.] 

 Eyepiece. An eyepiece is the lens or combination of lenses, next 



the observer's eye, used in microscopes or telescopes, etc., 



to examine the image formed at the focus'of'the'object-glass. 



[1, 2, 3, 8, 9, 10, 11, 13, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 



25, 26, 27.] 



