510 EXPERIMENT STATION RECORD. I Vol. 38 



"A number of determinations of (lie volume concentration of nitrogen peroxid 

 in the atmosphere during the prevalence of anticy clonic weather has shown 

 that at Canterbury, Victoria, in the rear circulation of anticyclones the air 

 contains a greater proportion of nitrogen peroxid than the air of the front 

 circulation. On the assumption that the oxidized nitrogen of the rainfall is 

 derived from the atmosphere, the amounts of nitrogen peroxid in the latter 

 were compared with the amounts of oxidized nitrogen found in the rainfall at 

 Canterbury for the corresponding weather types. It is shown that air con- 

 taining 0.56 volume of nitrogen peroxid per 10^ volumes in the rear of an 

 anticyclone would require to be washed out to a height of about 4,000 ft. above 

 ground-level in order to give the amount of oxidized nitrogen usually found 

 in the rainfall accompanying this weather condition. Similarly, in the case 

 of the front of an anticyclone, it is shown that the height would require to be 

 about 3,100 ft. The above are in fair agreement with the average altitude 

 of rain clouds (base), which according to leading authorities is about 3,500ft." 



Lunar period in the rates of evaporation and rainfall, J. R. Sutton (Ahs. 

 in Nature ILondon'i, 100 {1911), No. 250^, p. 160; U. S. Mo. Weather Rev., 45 

 (1917), No. 10, p. 501). — The paper "directs attention to the possibility of a 

 lunar influence governing the evaporation from a water surface, and a lunar 

 period in the incidence of rainfall. Tables are given showing that as the 

 result of hourly observations of evaporation and rainfall during the 120 lunar 

 months from August, 1899, to April, 1909, rainfall has its maximum frequency 

 about the time of moonrise and its minimum just after moonset ; also that the 

 rate of evaporation has a maximum and minimum, respectively, shortly after 

 the moon passes the meridian above and below the horizon." 



Torests and rainfall experiments (U. S. Mo. Weather Rev., 45 {1911), No. 9, 

 p. 453).— Referring to a review by H. R. Mill of an article by M. Hill (E. S. R., 

 37, p. 716), attention is called to the fact that one of the methods proposed by 

 Mill for studying the relations between rainfall and forestation has been 

 in use by the U. S. Weather Bureau, cooperating with the Forest Service, since 

 1910 in two contiguous and practically Identical watersheds in the Rio 

 Grande National Forest. These watersheds are " at present under identical 

 forested conditions, and have established therein a large number of thermom- 

 eter, precipitation, and stream-gauge stations. Careful observations will be 

 carried on in both watersheds for a number of years, and at the conclusion 

 of this first period one of the watersheds will be deforested and the same 

 observations continued for a second period corresponding to the first one." 



Monthly Weather Review {V. 8. Mo. Weather Rev., 45 {1911), Nos. 9, pp. 

 439-419, pis. 8, figs. 9; 10, pp. 480-528, pis. 9, figs. 11).— In addition to weather 

 forecasts, river and flood observations, and seismological reports for Septem- 

 ber and October, 1917 ; lists of additions to the Weather Bureau Library 

 and of recent papers on meteorology and seismology ; notes on the weather 

 of the months ; solar and sky radiation measurements at Washington, D. C, 

 during September and October, 1917 ; condensed climatological summaries ; 

 and the usual climatological tables and charts, these numbers contain the 

 following articles: 



No. 9. — D()ppler's Principle for a Windy Atmosphere, by H. Bateman ; Propa- 

 gation to Great Distances of the Sound of Cannonade at the Front, by G. 

 Bjgourdan ; Acoustic Efliciency of Fog-signal Machinery, by L. V. King ; Sur- 

 face Currents of Jupiter, by S. Bolton; Effect of Terrestrial Relief on Ionic 

 Densities in the Atmosphere, by P. L. Mercanton ; Observations of Atmospheric 

 Electricity During the Total Solar Eclipse on October 10, 1912, at Boa Vista, 

 Brazil, by W. Knoche and J. Laub ; Release of Radium Emanation from Water 



