55 



Ammoniameter. A hydrometer graduated to indicate the 

 strengths of ammonia solutions. [15.] 



Ampere Meter. See Ammeter. 



Amsler's Integrator. See Integrator. [21.} 



Amsler's Planimeter. See Planimeter. 



Anaerobic Apparatus. For obtaining cultures of bacteria which 

 do not grow in the presence of oxygen. [26.] 



Anaerobic Apparatus. An apparatus for obtaining plate cultures 

 of anaerobic bacteria. [26.] 



Anaerobic Apparatus, McGowan's. 



Anaerobic Apparatus, McLeod's. 



AnaUatic Telescope. A surveying telescope fitted with an 

 additional lens in the focal plane of the object-glass, in 

 order to avoid the necessity of adding a constant for 

 tacheometrical measurements. [3, 17, 18, 20, 21, 27.] 



Anastigmat. A lens corrected for astigmatism. [1, 3, 8, 18, 20, 

 23, 26.] 



Anastigmatic Objective. An object-glass (q.v.) corrected for 

 astigmatism. [1, 3, 8, 20, 25.] 



Anderson Slide-Rule. See Slide-Rule. [13, 15, 20.] 



Anemo Biagraph. See Anemograph. [15, 17, 20, 21.] 



Anemogram. The diagram of a recording anemometer. 



Anemograph. A recording anemometer- or wind-gauge. [15, 

 17, 20, 21.] 



Anemometer. An instrument for measuring the force and 

 velocity of the wind, or of currents of air or other gases. 

 There are two types : (i) Cup (or Robinson) Anemometer, 

 consisting of four hemispherical cups attached to the ends 

 of a light metal cross which rotates under the force of the 

 wind, the rate of revolution being registered on a dial, 

 counter or chart. (2) Pressure Tube (Dines's) Anemometer, 

 consisting essentially of a Pilot tube (q.v.) head connected 

 to a manometer, the wind exerting a pressure on one limb 

 and a suction on the other limb and the combined effect 

 being recorded on a chart or otherwise registered. [2, 5, 13, 

 15, 16, 17, 20, 21, 24, 25, 26, 27.] 



Anemometer, Fletcher's. For measuring the speed of flue gases 

 [13, 15, 17, 21.] 



Anemometer, Inclined Pattern. A form of pressure gauge for 

 measuring small pressures. A Pilot head is connected to a 

 U tube which can be inclined at any angle so as to vary the 

 sensibility. [6, 13, 16, 17, 20, 21, 24, 25.] 



Anemometer, Lea Biram. A special form of Biram anemometer 

 with one dial and one pointer. [13, 21.] 



Anemometer Pressure Plate. For indicating the pressure of 

 wind acting on the surface of a plate against a spring and 

 suspended to work over a vertical quadrant. [13, 15, 17, 21.] 



Anemoscope. An instrument which indicates the direction of 

 the wind. [13, 15, 17, 21.] 



