64 SEC. 3. MEASUREMENT. 



attached. It is not necessary to pierce or employ a tank when attaching one 

 of these gauges, and the small pipes -can be laid in the walls in a similar 

 manner to gas tubes. In some cases one tube is sufficient, the water column 

 being balanced by mercury in a metal tube at the back of the gauge. This 

 gauge is suitable for tanks upon the roofs of mansions or hotels, where engines 

 are used for pumping. 



327 c. Patent Indicator for Artesian or other deep wells, 

 or ships' bilge-well. John Nicholas. 



This instrument indicates the quantity or depth of water in a deep well or 

 pit, or the quantity of water in any vessel, as a ship's bilge, &c. It consists 

 of an elastic chamber at the bottom of the well, connected with a glass tube 

 and scale by a small lead pipe. This pipe and chamber are filled up with 

 coloured liquid until it can be seen at on the scale, the well being empty at 

 the time. Any pressure put upon the now distended chamber presses forward 

 the liquid along the glass tube, thus showing the depth of water above the 

 chamber. 



328. Indicator. 



Dreyer, Rosenkranz, and Droop, Hanover. 



329. Apparatus for determining the capacity of Car- 

 tridge-cases as far as 20 cub. mm. A. Bonsack, Berlin. 



330. New Volumeter, consisting of A. Sauer's burette, 

 a second glass piece, stands and tubes. 



(Compare Fresenius, " Zeitschrift fur analytische Chemie," xiv. 

 heft. 3 and 4). 



Berggewerkschafts-kasse at Bochttm, Dr. Heintzmann. 



331. Model of a Gas Meter of ancient construction, with 

 glass sides. 



School for Industry at Halle (Dr. Kohlmann, Director}. 



V. MEASUREMENT OF MASS. 



A. BALANCES. 



333. Balance, with double column, 20-inch beam, fitted with 

 steel knife edges working on agate planes, to carry 5 Ibs. in each 

 pan, and turn distinctly with 01 grain. Fitted with apparatus 

 for moving sliding weight without opening glass case. As made 

 for the Warden of Standards, for comparison of standard of standard 

 weights. L. Oertling. 



334. Balance, with double column, very light beam, 10 inches 

 long, fitted with agate knife edges and agate planes, to carry 

 30 grains in each pan, and turn distinctly with 001 grain, with 

 apparatus for moving sliding weight. L. Oertling 



