METEOROLOGY. 619 



■ "Of interest is the equation tm — <fi=l. 55 — 0.151 /( wlaich shows that at elevations 

 below 1,000 meters <inis greater than t,,; in other words that the evenings are warmer 

 than the morning hours. At elevations of 1,000 meters equal temperatures prevail 

 at 6 a. ra. and 10 p. m. . . . Tiie equations applied to vapor tension show that 

 the amount of aqueous vapor in the air decreases at the rate of 0.146 gm. per cubic 

 meter for each increase of 100 meters in the elevation. For the periodic variations 

 of vapor tension in millimeters at 6 a. m., 2 p. in., and 10 p. m. . . . the equa- 

 tions are 



S6=6.80— 0.16/(, S.. = (;.89— 0.103/(, Si„ = 7.19— 0.212/i. 



"It appears, therefore, that while the least vertical decrease of temperature occurs 

 in the early morning, the least vertical decrease of vapor takes place during the 

 afternoon. The greatest difterence in the amount of watery vapor on mountains 

 and over lowlands occurs at 10 p. m. 



"Relativehumidity, rainfall and snowfall, the frequency of rain, and the occurrence 

 of night fi'osts arc also treated by this formula to iind the variation of tliese factors 

 Avith change of elevation." 



Following the same nietliod with observations made during 1892 ou 

 the dates of blooming and harvesting of important field crops, the fol- 

 lowing fundamental equations were obtained: 



a b n /.I jLia Mb 



Eye, May 2-1 + 4.05/* 59 ± 5.4 ± 1-C ± 0.39 days. 



Wheat, June 17 + 2.83/( 28^4.4-1-2.1-1-0.67 days. 

 Oats, .Tune 28-|-3.41/( 41 J- 6.5 ±2.3 J- 0.57 days. 

 Barley, June 17 + 4.76/t 12-1-7.4-1-5.8 i 1.80 days. 

 Potatoes, July 3 + 1.82/( 23^6.8^3.04:0.76 days. 

 " [In these] n represents the number of stations from whose data the equations 

 were determined, /i represents the mean errors of the results. . . . 



"For the length of time between blooming and harvest the following eq^uations 

 were obtained : 



a in I.L Ma. Mh ■ 



Rye, 44-^2.55// 56i 7.3^2.2 -1-0.53 days. 



Wheat, 41 + 1.97/(27^ 5.1 + 2.5 J- 0.78 days. 

 Oats, 27 + 3.22/( 38 + 7.9 + 2.7 + 0.63 days. 

 Barley, 42 + 0.07/i 9+ 5.2 + 4.8 + 1.45 days. 

 Potatoes, 75 + OMh 16 + 10.5 + 7.7 + 2.05 days. 

 "If we combine the equations for time of blooming and for the difference betwer i 

 time of blooming and harvest, we obtain the equations for the date of harvesting: 

 Date of rye harvesting, July 6 + 6.6/(. 

 Date of wheat harvesting. July 28 + 4.8/t. 

 Date of oats harvesting, July 25 + 6.6/(. 

 Date of barley harvesting, July 29 + 4.8/j.. 

 Date of potato harvesting, Sept. 16 + 2.8/t." 



It is of especial interest to observe in the above tables that the time 

 of blooming of the principal cereals (rye, wheat, oats, and barley) is 

 retarded from 3 to 4 days and for potatoes about 2 days for each increase 

 of 100 meters in elevation, while the time of harvesting is retarded 

 from 5 to G^ days with cereals and 3 days with potatoes. — o. L. fassig. 



Records of four voyages of the balloon Svea, S. A. Andree 

 {Bihamj svensl-a Vet. Akail. Handl, 19 {1S93), II, No. 3, pp. 20, pis. 3; 

 20 {1891). II, Wo. 1, pp. 36, ph. 6; Ko. 3, pp. 30, pis. 5; No. 4, pp. 16, 

 pis. 5).— The capacity of the Svea is 37,200 cubic feet. The voyages 

 were made at Stockholm on July 15, August 9, and October 19, 1893, 



