METEOKOLOGY WATER. 529 



related to the turninj: points of the suuspot curve, the larger maximum of rain- 

 fall corresponiliiifj; to the suiispot iiiiiiinuun. the smaller to the suiispot maxi- 

 mum. A .'i5 years' cycle con'espoiuliufr to that de(Ui(<'(l In- r.riickiier Un- the 

 whole of Euroii(> se(>me(l to he lioi'ue out hy the data for North (k-rmaiiy. 



A viiluminous liihlid.^raphy oi' litcralure relating to German rainfall is given. 



Cirrus clouds and rain { Sciciicc. ii. .scr.. .i) (IDOC). Ao. lil'i, p. IS.',). — .\ 

 brief note is given on studies l)y \;ni(lerlinden at the Koyal Observatory of 

 Belgium at Uocle on the i-elation between the direction of movement of 

 cirrus clouds and the suhseipient occurrence of rain. The observations show in 

 general that cirrus clouds "do not appear always to lie the prognostics of 

 rain whicli they have been said to be." 



The Mount Rose weather observatory, J. E. Church. Jr., {Mo. Weather 

 Rer., SJf (1D()()), Ao. 6, pp. 2.).3-.i6U //f/.s-. 9). — An account is given in this article 

 of the establishment, with tlie cooperation of the Nevada Academy of Sciences, 

 the United States Weather Bureau, and the Nevada Agricultural Experiment 

 Station, of a small observing station on the sumnnt of this mountain which 

 forms the northern apex of the Carson Range of the Sierra Nevada and is 

 10.800 ft. high. The peak is near Reno, Nev., and coimnniids the Lake Tahoe 

 and Truckee and Carson valleys. It was selected because it was believed " that 

 an observatory here would be of service in furnishing data as to the constant 

 air movements from the I'ai-ific coast and in reporting approaching weather 

 conditions to the districts farther east." and would furnish a valuable means of 

 comparing the weather conditions of this high elevation with those of Reno in 

 the valley, 0,268 ft. below, and of San Francisco to the southwest. 



The records thus far made indicate a rather constant correspondence between 

 fall in pressure and fall in temperature, and furthermore, that such fall pre- 

 cedes by several hours (24 to .">(;) the appearance of frost in the Truckee and 

 Carson valleys below, thus furnishing a possible basis for frost prediction for 

 these valleys. 



In cooperation with the Nevada PLxperiment Station it is proposetl to continue 

 these frost studies and also to make investigations on precipitation and evapo- 

 ration at this high .nltitude as well as of other prol)lems having an agricultural 

 bearing. 



Water supply and sewerage (Ann. Rpt. Bd. Health Mas.^., 31 (1905). pp. 

 33-.'t2(), ftfiH. 3, charts 3). — This report contains as usual accounts of advice given 

 to cities, tow'ns, and public institutions regarding water and ice supply, sewerage 

 and sewage disposal, pollution of ponds, sti'eams, and other bodies of water, 

 etc., the results of examinations of public water supplies and rivers, and water 

 supply statistics, as well as articles on materials used for service pipes in 

 Massachusetts, experiments on the removal. of organisms from the waters of 

 ponds and reservoirs by the use of copper sulphate, investigations concerning 

 absorption and sedimentation of copper sulphate used as an algicide and con- 

 ceriung tiie bactericidal itroperties of copper and copper sulphate, experiments 

 on the purification of sewage and water at the Lawrence Ex])eriment Station 

 in 1905, and examination of sewer outlets and of tidal waters and flats from 

 which shellfish are taken. 



E.rperiments with copper siilpliatc on ponds and reservoirs (pp. 207-287). — Ex- 

 periments on a number of ])onds and reservoirs with varying amounts of copper 

 sulphate are reported, showing that the sulphate completely destroys certain 

 kinds of organisms but has little or no effect on others. " The C.vanophycejp, 

 which are among the most trcmblesome of the organisms wiiich cause disagree- 

 able tastes and odors in the waters of ponds and reservoirs, can be removed by 

 the application of cojjper sul]ihate in a quantity amounting approximately to 

 1 part of copper sulphate in 4,000,000 to 8,000,000 parts of water." Uroglena 



