45, CORNHILL, E.G., AND 122, REGENT STREET, W., LONDON. 187 



Q O 



FIG. 492. 



PAGE 168. 



FIG. 514. 



FIG. 517. 



FIG. 513. 



501 Fahrenheit's Hydrometer has two glass bulbs blown on a tube similar to the 

 ordinary hydrometer, the upper bulb being the larger. The top of the stem is 

 terminated by a small cup or dish. The lower bulb is weighted with mercury 

 sufficient to cause the partial immersion of the instrument when placed in water 

 without any weights being placed in this cup. In the middle of the stem is 

 a mark, to which point the hydrometer is adjusted in water by placing weights in 

 the cup. Its use is similar to that of Nicholson's Gravimeter. 10 6 



502 Densimeter, a modification of Fahrenheit's instrument, 



chiefly used in France 12 6 



503 Richter's and TraUe's Hydrometer, with Thermometer . . . 15 6 



504 Normal Alcoholometer, Tralle's, used in Prussia and the United 



States, has a scale figured from to 100, each degree repre- 

 senting one per cent, by volume of Alcohol, Specific Gravity 

 07939 in any mixture of Alcohol and Water at 60 degrees temper- 

 ature Fahrenheit 14 



505 Wooley's Hydrometer. This instrument has 2 scales, viz., 



Government Proof and Specific Gravity 066 



506 A set of five Standard* Glass Hydrometers. Government Proof 



Scale, forty under Proof to sixty over Proof, with a very accurate 

 Thermometer in a Mahogany Box, with Book of Tables as used 

 with the metal Hydrometer 400 



507 Hermbstadt's Hydrometer and Saccharometer, having two Scales, 



one showing Specific Gravity, I'OOO to T321 and percentage of 



Sugar to 67 066 



