7 8 



Curve-Tracer, Brearley. A semi-automatic apparatus for the 



recording of curves in any experiment in which the deflec- 

 tions of a galvanometer vary with time. Originally designed 



for obtaining recalescence curves on an open scale with 



rectangular co-ordinates. [4.] 

 Curves, Elliptic. Curves cut from a turned cone, used for 



drawing ellipses. [2. 6, 13, 15, 20, 21, 24, 27.] 

 Curves, Mathematical. Pieces of wood, celluloid, etc., cut in 



the forms of various curves for the use of draughtsmen. 



[2, 5, 6, 9, 13, 15, 17, 20, 21, 24, 25, 26, 27.} 

 Curvograph. See Arcograph. 



Cust's Station Pointer. See Radiograph. [13, 15, 21, 25.] 

 Cutting Compass. Drawing compasses, one of the legs of which 



is a cutter to cut washers, wads, and circular discs of paper, 



etc. [13, 21.] 



Cyanometer. An instrument for measuring degrees of blueness. 

 Cyclograph. See Arcograph. 

 Cyclograph, Hooke's. An instrument invented by Dr. Hooke for 



producing arcs of high radii by oblique rolling contact. 

 Cycloidograph. An instrument for the practical drawing of 



cycloids. [21.] 



Cycloids. An instrument for describing cycloidal curves. [27.] 

 Cyclonometer. An instrument for estimating the approximate 



direction and speed of approaching cyclones. [15.] 

 Cycloscope. A machine for measuring at any moment the 



velocity of rotation. 

 Cymograph. An instrument for taking full-size profile drawings 



from mouldings in brass. [21.] 

 Cystoscope. A small microscope or periscope with an illuminant, 



for inserting in various orifices of the human body for 



examination of disease. [1, 3, 13, 22, 26.] 



Dairy Acidimeter. See Acidimeter. [8, 13, 17, 21.] 



Daniell's Hygrometer. See Hygrometer. 



Dasymeter. An instrument for testing the density of gases. 

 It consists of a thin glass globe, which is weighed in the gas 

 or gases under observation, and then in an atmosphere of 

 known density. [21.] 



Davenport Air-Speed Indicator. A speed instrument for aero- 

 planes. 



Davis Biram Anemometer. An improved form of the Biram 

 anemometer. 



Davis-Blih-Hedley Dial. See Dial. [20, 21, 25.] 



Davis-Lee-Bottomley Slide-Rule. See Slide-Rule. 



Davis-Lyall Air Speed Indicator. See Miner's Dial. [21} 



Davis-Martin Wireless Slide-Rule. See Slide-Rule. [21.] 



Davis Self-Registering Water-Gauge and Clock. An instrument 

 for registering on a chart the water-gauge fluctuations in a 

 coal mine. [13, 21.] 



Davis Shutter. See Shutter. [2, 3, 21, 22. 26] 



