FERTILIZERS. 37 



The greatest difference between the readings of the 3-inch thermom- 

 eter for 4 years (1892-'95) was 1.8° ; for the G-inch, 1.4° ; the 12.iuch, 1.0° ; 

 the 24-inch, 1°; the 36-inch, l.GO; the 72-inch, 0.-7°. ' 



The public lauds aud their water supply, F. H. Newell ( U. S. Geological Sur- 

 vey Iipt.lS94- 05, pp. 463-533, pis. 5, figs. 10). — This is an account of a continuation of 

 work bej^nn by the Geological Survey in 1879. The purpose of the present paper is 

 "simply to point out the location of the public lands, to indicate in a general way 

 their extent and position, and to lay before the public such facts as have been 

 obtained concerning their broader physical characteristics, and their water supply. 

 The latter is still a subject of investigation, and although considerable work relating 

 to it has been done, in view of the enormous extent of country to be traversed it 

 cau hardly be said to be more than inaugurated." 



The classification of the public land was provided for in the organic law of the 

 Geological Survey approved March 3, 1879. The mapping aud studj^ of soil condi- 

 tions have proceeded rapidly, and facts regarding the phj^sical conditions of large 

 jiortions of the national domain are now available. A detailed map is given show- 

 ing the disposition made of public lands in the United States. Smaller maps are 

 given which show the relative location of forests, woodlands, and irrigated areas, 

 and the areas within which dry farming is attempted. The subject of water supply 

 is treated under the general heads of sources of supply, including streams, wells, 

 and reservoirs; and the supply of the individual States in the arid region. 



Nitrates in potable waters, T. Schlossing {Compt. Itend., 123 {189G), No. 19, pp. 

 1030-103S). — The results of examinations of three sources of water supply with ref- 

 erence to nitric nitrogea and lime during the spring and summer of 1895 are reported 

 in tables and diagrams. lu one case the average amount of nitrogen found was 10.26 

 mg., of lime 114.2 mg. per liter; in the others the figures were 11.61 and 106.5 mg., 

 and 10.84 and 86.3 mg., respectively. 



Analyses of drinking water, J. L. Hills and B. O. White ( Vermont Sia. Bpt. 

 1S94, pp. S4, 85). — Analyses with reference to drinking qualitj'^ of 12 samjiles of 

 spring water, 16 of well water, and 9 of reservoir or brook water are reported. 



FERTILIZERS. 



A phosphate deposit in Juniata County, Pennsylvania, M. C. 

 Ihlseng and ]\I. S. McDowell {Pennsylvania Sta. Bui. 34, irp. 14, pi. 

 l,Jig. 1). — A i^reliminary report of investigation of tlie geology and 

 chemical composition of a phosphate de^josit in this locality to which 

 the attention of the station was called in 1895. 



"The existence of an especially fertile narrow belt of soil along the two central 

 ridges of .luniata County has been known to observant farmers for years. It was in 

 this fertile belt that the discovery was made, along the outcrop of what is called 

 th(s Oriskauy sandstone. Between this and the overlying Onondaga limestone is a 

 decomposed mass of marls and sands in which the phosphatic material is found. The 

 seams lie conformably with the stratification of the country, and may be easily 

 traced. The prospect has not yet been developed, though trenches and drifts have 

 been dug at numerous points along the contact, giving evidence of a persistent belt 

 of i)hosphatic material which cau be easily mined, is accessible to railroad, and 

 incloses valuable material in amount sufficient to constitute an industry. 



"Three classes of phosphatic materials have thus far been discovered. The first 

 is a friable white rock, locally known as ' white vein,' containing in typical speci- 

 mens from 29 to 54 per cent of bone phosphate. The second consists of red nodules 

 similar in appearance to the so-called 'clay ironstones,' but containing from 45 to 



