740 



SCIENCE 



[N. S. Vol. XXXIII. No. 854 



similarly by departures in the average weather 

 conditions. Though the approximate date of 

 flowering is determined by heredity, the 

 weather conditions of the preceding season, 

 when the seeds are maturing, have no effect. 

 When the flowering stage is delayed because 

 of unfavorable conditions, a change to more 

 favorable weather will bring out the flowers 

 with a less amount of " accumulated tempera- 

 ture " than otherwise. In general. Dr. Van- 

 derlinden concludes that temperature and in- 

 solation outweigh all other climatic factors 

 in the development of the plant up to flores- 

 cence. 



Having been successful in the recovery of 

 sounding-balloons previously sent up at 

 Omaha, Neb., the United States Weather 

 Bureau again used this station as a base of 

 operations in a series of daily ascensions from 

 February 7 to March 3. As it is necessary to 

 recover the instrument carried by this form 

 of balloon in order to get the desired record, 

 the starting point must be well inland, as the 

 prevailing wind aloft invariably blows the bal- 

 loons eastward. At Mount Weather Observa- 

 tory, which is unsuitably located for this par- 

 ticular work, pilot balloons have been used 

 since March 1 to supplement the kite flights on 

 the days set apart for international coopera- 

 tion in aerological exploration. No attempt 

 is made to recover these balloons, as they carry 

 no instruments. By observing them with 

 transit-instruments until they disappear, the 

 velocity and the direction of the wind are 

 obtained. They have been used successfully 

 for this purpose at Blue Hill Observatory 

 since 1909. 



Though it has generally been supposed that 

 the rain gauge was invented by Castelli in the 

 early part of the seventeenth century, recent 

 discoveries seem to indicate that it was in use 

 in Korea at a much earlier date. In Volume 

 I. of the " Scientific Memoirs of the Korean 

 Meteorological Observatory," Dr. Y. Wada, 

 the director of the newly established weather 

 service of that country, states that in 1442 

 King Sejo had a cylindrical btonze gauge, 

 about 12 inches high and 5 inches in diameter, 

 in which the depth of the water was measured 



after each occurrence of precipitation. In one 

 which he has found, the cylinder stood in a 

 depression in a boulder upon the sides of 

 which an inscription gave the year and stated 

 the purpose of the gauge. Though similar 

 instruments were later used in other parts of 

 the same country. Dr. Wada has been unable 

 to recover any of the records, which were 

 doubtless preserved for a time. The latter 

 would be exceedingly interesting and valuable 

 at present in furnishing data concerning cli- 

 matic changes. Korea is a land of deficient 

 rainfall now, and the special efforts made to 

 measure it five centuries ago would seem to 

 indicate that it was an important factor in 

 the welfare of the jieople even at that early 

 date, suggesting similar conditions then. 



" Dynamic Meteorology and Hydrography," 

 by Professor V. Bjerknes, of the University 

 of Christiania, and various collaborators, has 

 recently been publshed by the Carnegie Insti- 

 tution of Washington. The greater part of 

 the volume consists of exhaustive discussions,' 

 in nine chapters, of the more important prob- 

 lems in statics. Diagrams, tables and mathe- 

 matical demonstrations are generously em- 

 ployed to make clear some of the complex 

 problems treated. The remainder of the book 

 consists of hydrographic and meteorological 

 tables. On account of the abstruse nature of 

 the matters discussed, not many will appre- 

 ciate the value of the work, but advanced 

 students will doubtless find it a notable con- 

 tribution. 



Two interesting discussions of the cold of 

 winter anticyclones are found in Symons's 

 Meteorological Magazine. In the March num- 

 ber Mr. W. H. Dines states that according to 

 the Greenwich records for the fifty years, 1841 

 to 1890, inclusive, a considerably larger num- 

 ber of days of frost occurred when the mean 

 barometric pressure was below 29.80 inches 

 than when it was above 30.20 inches. During 

 that period nearly every frost noted for 

 severity or length occurred in the low pressure 

 series. The statement concerning the sup- 

 posed cold in winter anticyclones in many 

 text-books he says is not substantiated by evi- 

 dence, and he suggests that the idea " may 



