Puur out^ alxml (Hic-lialf of the water in tlie llaHk ami put in a weighed cjuantity (10 

 grams) of the soil, whirh has V)een i)reviously dried at 110° C. for twenty-four hours. 

 Place the flask iu a shallow water bath and boil for two minutes in order to drive out 

 the soil air. Fill the flask with distilled water and bring to the same temperature at 

 which tlie ])revions weight was taken. Weigh. (See that flask is full when weight 

 is taken. ) 



Calculation. — Add weight oi soil used to weight of flask lilied with water and deduct 

 therefrom weight of flask tilled with water and sdl. The difference expresses the 

 weight of a volume of water equal to the (juantity of soil used. 



The speciflc gra^•ity is found by dividing the weight of the soil taken by the weight 

 of the water it has <lisi)laced. 



JUxjH'riiiiriit Nu. ^. 



DETEKM I NATION OK '111 K \<)I,IIMK WKKiUT, AI'J'AKKNT SI'KI'IFIC (iHAVITY, AND I'OKOSri'Y 



OF SOILS. 



Detennine the volume weight of four soils, Nos. 1, 2, 'A, and 4. Weigh the empty 

 tubes (fig. 11 ) carefully. Tse the soil direct from the bins and pour into the tube the 

 measure level full. Tlien place the tube in the compacting machine (flg. 12) and 



Fii;. 11.— Determination of volume wcigtit, apparent specific gravity, and porosity of soils. 



allow the weight to fall six times from the 12-inch mark. l'()iu- in anotliet; measure 

 of soil and repeat. Continue this until the tube is filled to the mark near the top. 

 Weigh. Determine at the same time with a special sample the hygroscopic^ water 

 which escapes at 110° C. Also determine the numl)er of cubic inches, or centimeters, 

 occupied by the soil in each tul)e. 



Calculations. — Subtract the weight of the empty tube plus the weight of hygro- 

 scopic water in the soil used from the weight of the filled tube. This will be the 

 weight of the given volume of soil. The volume weight of a cubic centimeter of soil 

 should then be calculated. 



By dividing the volume weight of the soil with the weight of the same volume of 

 water, the apparent specific gravity of the soil is obtained. 



By dividing this apparent specific gravity with the real specific gravity of the soil 

 obtained in experiment No. 1, and substracting from 100, the remainder expresses 



