14 



The Philippine Journal of Science 



1914 



we have substituted therefor a block of wood having adjacent 

 uniform vertical grooves faced with a glass plate. Any such 

 method assumes that the percentage of voids in the material 

 with the different sizes of the grains is identical, and for this 

 reason cannot be strictly accurate. Furthermore, clay and silt 

 cake in drying, and care has to be exercised that these are 

 broken up. We found a great variation in the sum of linear 

 measurement of the fractions of samples of different soils of 

 the same weight. Comparative determinations by weight and 

 by measurement are as follows: 



Table I. — Mechanical analyses of soils comparing determinations by weight 



and by measurement. 



Source. 



Batang^as 



Do-.- 



Do 



Do 



Do. 



Do 



Do..._ 



Do 



Do 



Do 



Do 



Do 



Do..._ 



Do 



Do..__ 



Do 



Do 



Do..._ 



Do 



Do 



Do _ 



Do... 



Mountain Province. 



Do..-_ 



Do... __. 



Do 



Do _. 



Do 



Do 



Do..__ 



Do _. 



Do.. 



Cagayan 



Do.. 



Do 



Do 



No. 



Coarse 

 sand, 

 1-0.5 

 mm. 



Percent. 

 0.8 



"5 



i>5 

 »10 

 blO 

 »15 

 bl5 

 «16 

 bl6 

 «28 

 bSS 

 a 29 

 b29 

 «30 

 b30 

 "36 

 b36 

 »37 

 b37 

 »38 

 b38 

 a 41 

 t.41 



•3 



b3 



»8 



"8 

 al2 

 6 12 

 a 20 

 6 20 

 «33 

 1-33 



a? 



67 



«8 

 i>8 

 By weight, 



1.1 

 0.6 

 1.3 

 1.0 

 1.3 

 0.5 

 1.0 

 0.7 

 0.7 

 0.1 

 0.7 

 0.2 

 0.1 

 2.1 

 3.4 

 2.9 

 2.5 

 2.1 

 2.1 

 2.8 

 2.8 

 1.2 

 1.1 

 4.1 

 3.4 

 3.5 

 4.2 

 5.6 

 13.3 

 24.6 

 27.9 



Medium 



sand, 



0.5-0.25 



Per cent. 

 3.7 

 4.2 

 2.7 

 7.6 

 2.7 

 4.1 

 1.9 

 7.6 

 2.9 

 1.9 

 0.6 

 4.7 

 0.8 

 1.6 

 5.6 

 11.9 

 5.2 

 5.2 

 12.0 

 8.8 

 5.4 

 5.9 

 4.0 

 4.6 

 7.2 

 7.9 

 5.4 

 8.5 

 10.6 

 12.9 

 25.1 

 26.6 

 1.5 

 1.9 

 1.1 

 1.2 



Fine Very fine 



sand, I sand, 



0.25-0.10 i 0.10-0.05 

 mm. 



Percent. 



9.8 



8.7 



16.9 



16.8 



10.9 



12.0 



20.0 



16.8 



9.5 



10.8 



16.6 



17.5 



18.5 



15.0 



23.6 



18.2 



13.3 



9.2 



27.2 



20.1 



14.6 



10.2 



8.1 



7.3 



18.7 



14.4 



18.7 



10.7 



25.2 



12.6 



5.2 



7.3 



23.6 



20.6 



18.9 



16.0 



b 



Per cent. 

 13.9 

 12:1 

 U.4 

 13.2 

 16.1 

 22.1 

 14.8 

 14.8 

 12.6 

 12.2 

 31.7 

 27.8 

 29.4 

 30.0 

 18.4 

 16.3 

 15.5 

 15.8 

 9.5 

 12.4 

 19.8 

 17.3 

 7.9 

 7.7 

 13.4 

 13.7 

 19.9 

 16.1 

 13.6 

 13.6 

 15.5 

 16.3 

 36.7 

 35.7 

 37.2 

 36.8 



Silt, 



0.05-0.01 



mm. 



Per cent. 

 19.0 

 19.2 

 14.4 

 19.5 

 19.0 

 18.1 

 6.3 

 6.6 

 23.0 

 24.1 

 17.7 

 15.4 

 18.3 

 18.9 

 15.5 

 15.4 

 19.2 

 20.9 

 15.6 

 11.9 

 15.3 

 15.0 

 8.9 

 10.8 

 13.6 

 16.6 

 15.3 

 19.7 

 12.1 

 15.0 

 6.3 

 7.2 

 12.0 

 11.2 

 12.4 

 12.7 



Fine silt, 



0.01-0.002 



mm. 



Per cent. 

 40.9 

 41.9 

 31.2 

 31.3 

 34.7 

 31.6 

 29.3 

 28.9 

 32.4 

 32.8 

 26.0 

 26.4 

 24.3 

 25.6 

 23.7 

 24.3 

 31.8 

 35.8 

 21.0 

 28.3 

 30.6 

 37.4 

 42,1 

 41.8 

 26.4 

 33.3 

 29.2 

 32.7 

 21.8 

 22.5 

 9.9 

 6.7 

 21.0 

 23.5 

 23.4 

 26.0 



Clay lesB 



than 0.002 



mm. 



Percent. 



11.9 



12.8 



22.8 



10.3 



17.1 



10.8 



27.2 



24.3 



18.9 



17.5 



7.3 



7.6 



8.6 



8.8 



11.1 



10.5 



12.1 



10.6 



12.6 



16.4 



11.5 



11.4 



27.8 



26.7 



16.6 



11.8 



8.0 



8.1 



11.1 



10.1 



13.4 



8.0 



6.2 



7.1 



6.0 



7.3 



By measurement. 



