FACTS ABOUT WATER 



263 



Use of Water Pressure. Water pressure is used to turn water 

 wheels, and to run machinery in factories, in electric generating 

 stations, etc. The most popular type of water wheel to-day is the 

 turbine. 



TABLE OF DENSITIES 



DENSITIES IN GRAMS PER CUBIC CENTIMETER 



Aluminum ............... 2 . 67 



Antimony, cast ........... 6.7 



Beeswax 



96 



Bismuth, cast ............ 9.8 



Brass . 



8.4 



Copper 8 . 8-8 . 9 



Cork '. 14-. 24 



Galena 7.58 



German silver 8.5 



Glass, crown 2.5 



Glass, flint 3-3.5 



Gold 19.3 



Irpn, bar 7.8 



Iron, cast 7 . 2-7 . 3 



Ivory 1.9 



Lead 11.3-11.4 



Marble 2.72 



Mercury, at C 13 . 596 



Platinum 21.5 



Quartz 2 . 65 



Silver 10.4-10.5 



Steel 7.8-7.9 



Sulphur, native 2 . 03 



Tin 7.3 



Zinc, cast 6.86 



Water pressure is used for supplying cities and towns with water 

 from either reservoirs or lakes higher than the town, from which the 

 water flows into a standpipe higher than any of the buildings in the 

 town. All water is taken from reservoirs and pumped into a stand- 

 pipe. 



The diagrams will show the different methods of supplying towns 

 with water. It will be seen that the water coming from faucets 



Alcohol (95 per cent) 82 



Blood 1.06 



Carbon disulphide. 1 . 29 



Chloroform 5 



Copper sulphate solution . . 16 



Ether 72 



Glycerine 27 



Hydrochloric acid 22 



Nitric acid 5 



Sulphuric acid (15%) 10 



Sulphuric acid 1.8 



Water (4 C.) 1.000 



Water, sea 1 . 026 



GASES AT C. AND 76 CM. 

 PRESSURE 



Carbon dioxide 001977 



Hydrogen 0000896 



Nitrogen 001256 



Oxygen. 001430 



