soils — FEBtlLIZEB .".1 1 



tod (3) an outlet which can be fitted with delivery tubes of any desired diamei 

 The methods of standardizing this apparatus are described, as well as the differenl 

 Bteps in a mechanical analj sis. 



The author emphasizes the Importance of taking account of coarser constitui 

 the soil in order that the mechanical analysis may serve as a guide to the structure 

 and physical properties of a soil as it exists in nature. With this object in view he 

 begins with a few kilograms of soil from a typical position and picks oul all b1 

 larger than 5 cm. in diameter. One kg. of the soil from which these largt 

 have been removed is passed through a sieve with meshes l cm. in diameter. The 

 stones collected on ihe sieve are washed, dried at aboul 90 , and weighed. Five 

 hundred gm. of the material passing this sieve is pul through a Bieve with circular 

 holes 1 mm. in diameter. The material remaining on the sieve is washed, dried, 

 and weighed. Twenty gm. of the material passing the Bieve, dried at 9i 

 boiled in a porcelain dish for I hour with constant si irring and gentle pestling with 

 a rubber-tipped class rod, and is used for elutriation in the apparatus described. 



Mechanical analyses of soils and subsoils by centrifugal action ; with 

 notes on treatment of samples, .1. K. Kilroe [Econ. Proc. Roy. Dublin 5 

 1 {1904), No. 5, A, pp. .'.'■: ?S0, figs. 2). — The method proposed is a combination 

 of those <>f Whitney and Bennigsen, and is thus described: 



'• Adopting the idea of an inverted flask, attach a tube firmly to it, BO a- to make 



this serve as a prolongation of the neck, [nto the flask thus fitted, earth is intro- 

 duced, and distilled water poured in, so as almosl entirely to till the neck with 

 clear liquid. The tube is then corked (with india-rubber stopper), a sheath of tin 

 i- slipped down over the neck and secured by pliahle copper wires to a leather base 

 or cradle, which fitsclosely to the bottom of the bulb, and hears the extreme statical 

 pressure resulting from the rotary motion. The flasks are then fixed securely on 

 the centrifugal table .... with the hulhs inward and the tubes outward, the 

 extremities being about 15 in. from the axis of rotation. 



"*\Yhen the table is revolved for a short time, at 900 revolutions per minute, the 

 coarser particles become precipitated, and so consolidated that, at the close of the 

 operation, when the tlask is removed from the table and held with the bulbs down- 

 ward, the sand and coarse silt remain in the tube, and the clay and tine silt, form mil' 



the fluid mixture, are found in the flask. The chief advantage of the apparatus is 



that the detachable tube admits of the easy removal of the sand and silt. . . . 



"The detailed procedure, as practiced in the examination of soils and subsoils at 



the I reological Survey of lice, is as follows: In the case of line homogeneous earths, a 



quantity of soil or subsoil, dried and averaged, is taken, and passed through a 2 nun. 

 sieve; of this 20 gm., if a sandy soil, 25 if a loam, and ."><> if a clay, are taken for 

 treatment. It is boiled with distilled water for some hours, to loosen the clay from 

 the sands ami silts. 



"The mixture i- then thoroughly shaken to break up the compound particles 

 and detach the clay from the sand particles. It is then transferred to the flask, and 

 the latter nearly filled with distilled water to within an inch of the outer end of the 

 connected tithe. If this he carefully done, the neck is filled with clear water. The 



sheath is run down over the tube and neck of the flask, and fastened to the base "I 



the tlask. The bulb is then shaken to detach all particles from the bottom, and the 

 Whole inverted. The coarser sand and silt fall down through the clear liquid in 

 the tube, and are thus free from clay particle-." 



Soil moisture investigations for the season of 1904, .1. I >. Tissi w\ and .1. .1. 

 Vernon | New Mexico Shi. Bui. 54, /'/'• *7 t figs. •/'). — This is a continuation of experi- 

 ments of previous year- (E. 8. R., 15, p. 1060). As in the previous year the crop 

 grown was wheat. 



The results in 1903 having indicated that the application of water while w heat was 

 heading ami tilling was more beneficial than its' application before this time, the 



