118 EXPERIMENT STATION RECORD. 



C. Kicliet, based uiK)n interruptions of the How of the current of air while 

 in contact with viscous li(iui(ls, {glycerin and soap solution, or simply water. 



The duration of hailstorms (Rcr. *S'(/. [Paris], p' (1!)0!)), II, 'So. 11', p. 533). — 

 This is a note on a report by IMnniandon on a largo number of observations 

 from 1886 to 1908. While a lar.ce inimber of the storms observed were of short 

 duration some of them lasl(>d as lonj^ as an hour. Storms of long duration were 

 observed at all altitudes from 300 to 1,200 meters. No general cause is assigned 

 for such storms. 



A test of hail protection, re Beauchamp (Compt. Rend. Acad. 8ci. [Paris], 

 J/,9 (1909). No. 1, p. 73; abs. in Jour. Agr. Prat., n. ser., 18 {1909), No. J,9, p. 

 767). — An attempt to dissipate hailstorms in a region near Vienna subject to 

 great damage from this source by means of high towers carrying metal con- 

 ductors connecting with copper plates in contact with the ground water i^^ 

 briefly described. 



Some observations on dew ponds, E. A. ISIartin {Geogr. Jour., 3Jf {1909), No. 

 2, pp 174-195, dgms. 7; ab.s. in Nature [London], 81 {1909), No. 2085, pp. J,58, 

 J/59). — This article reports a series of observations in Sussex on methods of 

 construction and conditions determining the filling of dew ponds. The observa- 

 tions indicate that dew furnishes a comparatively small part of the water col- 

 lected in these ponds, particularly in case of ponds on the lower lands. During 

 the winter, rain, snow, and mist as well as dew contribute to the water supply. 

 In summer and in times of drought the water supply is derived from mist, fog, 

 and dew. 



Dew ponds {Agr. Students' Gaz., n. scr., U, {1909), No. .',, pp. 105-107).— This 

 is a concise summary of information regarding the nature, construction, and 

 use of dew ponds. 



Fluorescent substances in waters, F. Dienert {Ann. Observ. Munic. {Obscrv. 

 Montsouris) [Paris]. 9 {190S), No. 3-',, pp. 322-325, fig. i ) .—Apparatus and 

 delicate methods for studying fluorescent substances in waters are described. 



Methods used for measuring fluorescence in waters, F. Dienert {Ann, 

 Observ. Munic. {Observ. Montsouris) [Paris], 9 {1908), No. 3-1,, pp. 326-328, 

 figs. 2). — Apparatus and delicate methods for this purpose are described. 



The use of the acoustele in hydrology, F. Dienert {Ann. Otiscrv. Munic. 

 (Observ. Montsouris) [Paris], 9 {1908), No. 3-4, pp. 315-321, figs. 2).— The con- 

 struction of the Daguin acoustele, an acoustic cornet, is described and its use in 

 locating undergi'ound water is explained. 



Study of the subterranean waters of Paris, P. Miquel {Ann. Observ. Munic. 

 (Observ. Montsouris) [Paris], 9 (1908), No. 3-1,, pp. 303-^05).— Detailed ex- 

 aminations of a number of samples are reported. 



Potable and drainage waters of Paris, P. Miquel {Ann. Observ. Munic. 

 {Observ.' Montsouris) [Paris], 9 (1908), No. 3-J,, pp. 258^0//).— Bacteriological 

 and chemical examinations of samples of water from reservoirs in Paris and 

 its environs and from fountains, schools, and the Seine, as well as of sewage, 

 are reported. 



Pure water in town and country (Va. Health Buh, 1 (1909), No. 1',, pp. 363- 

 376, figs. 6). — It is stated that the purpose of this bulletin is to explain the 

 conditions which are necessary for the maintenance of a good water supply and 

 those which lead to contamination and impurity of water. Simple means of 

 protecting springs and wells from pollution are described. 



Drinking water on trains {Va. Health BuL, 1 (1909), No. 10, pp. 284, 285).— 

 The water supply on railroad trains in Virginia was found by the state board 

 of health to be satisfactory but objections were made to the manner of handling 

 ice. It is stated that the railroads have ample regulations for such matters 

 but that they are disregarded. 



