63 



Synonym for a Field Glass (q.v.). [2, 3, 5, 9, 10, 13, 15, 16, 

 17, 18, 20, 21, 22, 24, 25, 26, 27, 28.] 



Binocular, Galilean. A binocular constructed on the same prin- 

 ciples as the Galilean Telescope (q.v.). 



Binocular Magnifier. See Magnifying Glass. [2, 3, 10, 13, 15, 



20, 26, 27.] 



Binocular Microscope. See Microscope. [2, 3, 5, 9, 15, 17, 20, 



21, 22, 27.] 



Binocular Telescope. See Telescope. [2, 3, 5, 9, 15, 17, 20, 21, 



22, 27.] 



Bioscope. See Cinematograph. [3, 20.] 



Biram Air Meter or Anemometer. A form of anemometer (q.v.) 



with revolving vanes for registering the rate of air currents 



in mines, etc. [2, 5, 6, 10, 13, 15, 16, 17, 21, 24, 27.] 

 Birt's Buoy & Nipper. An apparatus or device used on a ship 



for obtaining a vertical or plumb sounding. [15.] 

 Bisecting Compasses. See Bisecting Divider. [6, 13, 15, 17, 21, 



24, 27.] 



Bisecting Divider. See Divider. [2, 6, 13, 15, 17, 21, 24, 27.] 

 Blackburn's Pendulum. See Pendulum. 

 Blanchimeter. An instrument for measuring the bleaching 



power of chloride of lime and potash. 

 Blast-Meter. An anemometer or wind-gauge as applied to the 



nozzle of a blowing engine, etc. [17.] 

 Blast Recorder. An instrument for recording on a revolving 



drum the duration, pressure and time of a blast. [5, 6.] 

 Blind Scale Thermometer. See Thermometer. [4, 5, 6, 13, 15, 



16, 17, 20, 21.] 



Blisch Horizon Corrector Prism. An instrument for attaching 



to any sextant, and giving the correction for dip and 



refraction. [15.] 

 Boiling Point Apparatus. An instrument, called a hypsometer 



(q.v.), used for determining altitudes by observation of the 



boiling points of water. [2, 5, 6, 13, 15, 17, 21, 24, 25, 27.] 

 Bolometer. An instrument for measuring minute quantities of 



radiant heat, especially in different parts of the spectrum ; 



called also Actinic Balance and Thermic Balance. [4, 19.] 

 Bone and Wheeler's Gas Analysis Apparatus. For gas analysis 



purposes. 

 Boning-Rods. Stout T-squares used with mechanic's levels in 



surveying work. [5, 6, 13, 15, 16, 21, 24, 25, 27.] 

 Borda Pendulum. -.See Pendulum. 

 Bordering Pen. A special form of pen for drawing in border 



lines on plans and maps. [5, 6, 13, 15, 17, 20, 21, 25, 27.] 

 Bo's'un Reel. A simple form of sounding winch. [13, 15, 28.] 

 Boucher's Calculating Circle. See Slide-Rule. [5, 13, 15, 17, 21, 



24, 27.] 

 Bourdon's Pressure Gauge. See Pressure Gauge. [5, 13, 15, 16, 



17, 21, 27, 28.] 



Bow Calliper. See Calliper. [6, 15, 20, 24, 26, 27.] 



