SOILS FERT.ILIZEKS. 19 



"The section of the Rillito Valley, as exposed by five deep test wells, 

 together with numerous shallow wells, consists of a porous gravelly recent fill 

 underlain by an older, nearly impervious main valley fill. 



" The water-bearing gravel of the recent fill is clean, coarse, well-sorted, and 

 porous, and affords extensive ground-water storage. 



" The main fill is compacted, and nearly impervious and sustains the ground 

 water at shallow depths. In arid valleys where the main fill is pervious, the 

 underdrainage may exceed the inflow and consequently no ground water may 

 exist except at great depths. . . . 



" The fluctuations of the water table are extreme beneath the Rillito bottom- 

 land, becoming less with distance away from the river. Waves of flow starting 

 from the river during flood seasons have been traced underground away from 

 the river toward the south. . . . 



" The porous character of the Rillito fill, the high rate of underflow observed, 

 well sections, pumping tests, and seepage measurements unite to demonstrate a 

 large ground-water supply, of which, however, existing data do not permit exact 

 computation. . . . 



" The development of Rillito ground waters must be mainly by pumping. 

 Individual pumping plants as now existing and in use, are poorly designed, 

 unintelligently operated, and furnish water only at very high cost per acre-foot." 



Cooperative ownership and operation of large plants is considered the most 

 economical and efficient means of pumping the water for irrigation. A plan 

 for such a cooperative enterprise is described in detail. 



Water-logging' of the Nile Valley, H. G. J. de Lotbinieke ( Cairo Sci. Jour., 

 4 (1910), iYo. 4S, pp. 221-223, pi. i).— It is pointed out in this article that as a 

 result of the uneven character of the alluvium of the Nile Valley and of over- 

 irrigation and seepage from high level canals water-logged areas are of frequent 

 occurrence in the soils. To find a remedy for such conditions it will be neces- 

 sary to devise a method of drainage based upon a careful study of the char- 

 acter of the soil. 



The water, O. Anselmino (Das Wasser. Leipsic, 1910, pp. VI +122. flgs. 

 44). — This booklet treats briefly and simply of the chemistry of water, the 

 water of the earth, purification of water, drinking water, mineral waters, and 

 difl:usion. 



SOILS— FERTILIZERS. 



The soils and soil-formers of the subantarctic islands, B. C. Aston ( Reprint 

 from Subantarctic Islajids of New Zealand. Wellington, N. Z., 1909, pp. 

 145-1111, pis. 12). — This report on soil investigations in the subantarctic islands 

 of New Zealand is divided into descriptions and analyses of the humus of the 

 Auckland, Campbell, and Antipodes islands; analyses of rocks and minerals 

 from Campbell, Euderby, and Auckland islands, and of the products of their 

 weathering; analyses of granite from Snares and Bounty islands; and analyses 

 of sea-lions' and sea-birds' dung from Snares and Bounty islands, respectively. 



A purpose of these investigations was to indicate why the soils of these islands 

 are so abundantly supplied with humus. It was found that the soils " are for 

 the greater part not formed in the manner in which peat in its special sense is 

 formed, inasmuch as («) they are derived chiefly from the decay of the higher 

 plants (Filices, Juncacese, Gramineje, Araliacere, Umbelliferae, Composita?, Lili- 

 aceae,' Rubiacese, Myrsinese, and Epacridacese) on the uplands and unforested 

 areas, and from Filices, Myrtaceas, Epacridacete, Araliacese, and Compositiie in 

 the forests; (&) they are not formed in or under stagnant water, [and] many 

 of the soils must have been formed on a steep hillside, with every advantage of 

 drainage which such a position could afford . . . ; (c) they support a vigorous 



