218 EXPERIMENT STATION BECORD. 



Underground water in crystalline rocks, V. (i. ('lapp {ttngin. Rec., 60 

 (1909), No. 19, pp. o2o-527, //f/.s. S). — This article deals with the mode of occur- 

 rence of water in crystalline rocks and the sinking of wells to obtain a water 

 supply under such conditions. 



It is stated that it is safe to assume " that a well drilled in crystalline rocks 

 will, with about 90 per cent of probability, strike enough water to supply a 

 family for domestic purposes. The probability that enough water will be found 

 within 100 ft. of the surface is about 85 per cent. It is not well to give up 

 without siidving at least 200 ft., hut drilling over 200 ft. is not advised, although 

 a few wi'lls have got water at greater depths. If a well owner is unfortunate 

 and does not obtain sntlicient water at that dei)th. he is advised to sink a 

 second well 100 ft. or more distant, and the chances are good that he will be 

 successful in the second attempt if not in the first. 



"Although water in these rocks is moderately charged with mineral matter, 

 they are not hard, and are not known in many cases to contain sufficient iron 

 or other mineral to interfere wi'rh their use. They are good for laundry and 

 boiler purposes, but the supi)ly is seldom sufficient for large plants. The cost 

 of drilling in these rocks is high, but deep wells in them will always pay in the 

 long run." 



The selection of a water supply, H. X. Ogden (Pror. Ann. Conf. Sanit. Off. 

 N. Y., S {1908), pp. 161-171, dgrns. 2). — The conditions and requirements of a 

 wholesome water supply are explained. 



The location, construction, and care of wells, L. M. Wachter (Proc. Ann. 

 Vonf. ^^anit. Off. N. Y., 8 (1908), pp. 172-182) .—The general requirements in the 

 location, construction, and care of wells are explained. 



The pollution of streams by domestic sewage and industrial wastes, T. 

 HoRToN (Pro€. Ann. Conf. Sanit. Off. N. Y., 8 (1908), pp. 136-1 'i6) .—The danger 

 from this source is pointed out. 



Report on sewerage and water supplies, H. jNI. Herbert (Ann. Rpt. Bd. 

 Health N. J., 32 (1908). pp. 265-.'i52, pis. //).— This is a report of the state sew- 

 erage commission and of the division of sewerage and water supplies of the 

 New Jersey State Board of Health for the year which began November 1, 1907. 

 It contains detailed reports on various water supplies, sewerage systems, and dis- 

 posal plants throughout the State, and discusses the danger of polluted water 

 as a means of directly or indirectly transmitting disease. The rapidly growing 

 need for careful supervision of public water supplies, including thorough in- 

 spection of the entire watershed from which the supplies are drawn, is strongly 

 emphasized. 



Attention is also called to railroads as a source of danger in the spread of 

 disease. 



It is stated that the artesian well supplies of New Jersey are in good condi- 

 tion. The waters, however, are not always wholly acceptable to the consumer 

 on account of the extreme hardness or excess of iron. 



The surface supplies of the State are filtered and in most cases well purified. 

 The filtration plants in some cases were found to be in bad condition and had 

 become an additional source of pollution to the water. 



Purification of potable waters (Bill. Off. Intrrnat. Hi/ft. PidJ. [Paris], 1 

 (1909), No. 3, pp. 206-220).— This is an extract of the reports of city officials 

 having charge of the water and drainage of Paris, and describes briefly the 

 various methods which are being employed for obtaining a pure water supply for 

 the city. 



