118 EXPERIMENT STATION EECOED. 



For the summations of temi^erature efficiencies, the normal daily efficiencies cor- 

 responding, respectively, to the normal daily means of Bigelow's tables have 

 simply been added for the same days as in the direct summations, thus giving 

 what may be termed a tentative index of temperature efficiency for growth dur- 

 ing the normal frostless season." 



The general conclusions reached are that " the method of direct temperature 

 summations has proved itself to give, in a b.roadly general way and for most of 

 the area of the United States, nearly the same climatic zones as does [the] 

 method of efficiency summations. . . . The similarity between the results de- 

 rived by these two methods of temperature integration, however, is only 

 superficial and roughly approximate. The ratios of direct summation to 

 efficiency summation range in magnitude, for the mean frostless season in the 

 United States, from a minimum of 7.49 to a maximum of 10.44. A rational and 

 consistent climatic chart represents the geographical distribution of these ratio 

 values; on such a chart the marginal regions of the country are frequently 

 characterized by low ratios and the two main mountain systems appear to con- 

 trol areas of high values. There seems to be no doubt that the ratio here 

 brought forward quantitatively represents a climatic dimension or characteris- 

 tic, which appears to be some sort of function of the daily normal temperatures 

 upon which this whole study has been based and of the time distribution of 

 these temperature data within the period of the mean frostless season." 



British rainfall, 1912, H. R. IVIill and C. Salter {London, 1912, pp. 372, 

 pis. Jf, figs, 87). — This report summarizes observations at 5,272 stations in Great 

 Britain and Ireland grouped by counties and river basins. 



The mean rainfall during the year was 39.31 in., 23 per cent above the av- 

 erage for 35 years (1875-1909), for England; 56.19 in., 19 per cent above the 

 average, for Wales; 49.01 in., 11 per cent above the average, for Scotland; and 

 44.06 in., 8 per cent above the average, for Ireland. "Within the last 32 years 

 for which comparisons are available, two only (1882 and 1903) have been wetter 

 than 1912 in the British Isles. 



The report contains special articles on the great rain storm of August 25-26, 

 1912; the wettest summer in England and Wales; and the "Seathwaite" pat- 

 tern rain gage. 



Evaporation from a plain water surface, J. W. Leather (Mem-. Depf. Agr. 

 India, Cliem. Ser., 3 {1913), No. 1, pp. 15, pi. 1, figs. 2; al)S. in Internat. Inst. 

 Agr. [Rome'], Mo. Bui. Agr, Intel, and Plant Diseases, 4 {1912), No, 8, pp. 

 1186, 1187). — ^A description is given of the evaporimeter in use at Pusa, which 

 consists essentially of a circular cement tank 6* ft. in diameter and 5 ft. deep, 

 with an adjustable pointer for measuring the water level. Records for 1911 

 and 1912 are tabulated and compared with other data obtained from the obser- 

 vatories at Madras and Lyallpur. 



The rate of evaporation during the cold weather months was much the same 

 at Pusa and at Lyallpur but was much higher at Lyallpur throughout the six 

 hot months from May to October. At Pusa during the hottest months the rate 

 of evaporation was three times that of the coldest months, at Lyallpur five 

 times, and at Madras not quite twice that of the coldest months. 



Dew ponds and mist ponds, E. A. Martin {Rpt. Brit. Assoc. Adv. Set., 1912, 

 pp. 530, 531). — ^An attempt is made in this article to explain the accumulation 

 of water in these ponds. " The precipitation of mist into ponds, aided perhaps 

 by silent discharges of electricity, and the entanglement of mist-laden salt dust 

 in the hollows in which the ponds lie. are believed to be the means by which 

 some ponds maintain a supply of water all through the year, in spite of the 

 great draft which is made uix>n them by numerous cattle." 



