268 



SCIENCE 



[N. S. Vol. LIV. No. 1395 



quite imconscious of the fact that the camera 

 was winking at the mountain slope when I 

 thought it was photographing the lake. 



In the vertical view features are flattened. 

 This is true for vision and is even more pro- 

 nouncedly true in photographs. It would be 

 desirable therefore to observe during the ear- 

 lier and later hours of the day when shadows 

 are strong. The swiftness of flight makes this 

 practicable, since miles become short when 

 expressed in minutes and a distant field of 

 study can be reached quickly. Photography, 

 however, requires the strongest light possible 

 because the exposure must be very brief when 

 the camera is moving a hundred miles an hour, 

 and this requirement limits the available hours 

 to those when shadows are weak or lacking. 

 The effect of this limitation is yet to be worked 

 out, but since rift features are to a great ex- 

 tent relief features, it is of consequence. 



So far as the trial flights of June 9 and 11 

 go they seem to demonstrate that aerial ob- 

 servation of a linear structural feature such 

 as an earthquake rift is practicable. If one 

 end of a rift be known it can be followed by a 

 man skilled in the interpretation of topo- 

 graphic forms. Or if a line of features be 

 detected, it may be so traced as to demonstrate 

 their continuity and to facilitate the closer 

 examination which may be necessary to prove 

 the existence of a fault. I conclude that the 

 airplane can be used to advantage as a means 

 of rapid geologic reconaissance to map large 

 structural features. 



Bailey Willis 



SCIENTIFIC EVENTS 

 INTERNATIONAL EXPLORATION OF THE UP- 

 PER AIR 1 



INTERNATIONAL cxploratiou of the upper air 

 dates from 1896, when a conference took place 

 at Petrograd. Methods of sounding the atmo- 

 sphere, even to a height of 23 miles, were 

 devised. By the use of drifting free balloons, 

 and recording instruments carried up by kites 

 and anchored balloons, an unexpected strati- 

 fication of the atmosphere has been discovered. 

 The temperature falls regularly up to a height 

 averaging six or seven miles from the ground, 



" rrom the London Times. 



lower over the equator, higher near the poles. 

 But the upper air is arranged in vertical 

 columns in which the temperature is constant 

 with height at any particular time and place. 

 Little is known as to the cause of this dis- 

 position, and less as to the influence it must 

 have on other factors of wind and weather. 

 Useful knowledge can be gained only from 

 data obtained by the same methods at the 

 same times at the largest possible number of 

 stations. International cooperation is neces- 

 sary. It was interrupted by the war, although 

 all the combatants made extensive use of the 

 latest meteorological methods for the practical 

 objects of artillery, aviation, poison gas, and 

 sound-ranging. It has now been resumed. The 

 other day we gave an account of the proceed- 

 ings of the first meeting since the war, held at 

 Bergen, in the last week of July, under the 

 presidency of Professor V. Bjerknes. The 

 name of that distinguished Norwegian mete- 

 orologist is associated with a new theory of 

 the weather in temperate latitudes, on which 

 we commented a year ago. The theory briefly 

 is that just as the poles are capped with snow 

 so they are capped by a great mass of cold air. 

 In a wavering line round each temperate zone 

 this polar air meets the warm air from the 

 equator abruptly. Along the front of contact 

 the warm air rises over the cold stream. 

 Cyclones and anticyclones are born of the con- 

 test. The professor urges the formation of a 

 closely set chain of observing stations round 

 the globe in the zone of struggle. Other 

 meteorologists are more disposed to assign the 

 causes of our weather to the vaster regions of 

 the upper air. An international meteorological 

 committee, to meet in London in September, 

 has been appointed by the Commission, and is 

 to give special attention to the polar theory. 

 The progress of its labors will be followed with 

 deep interest. There are few human activities 

 which would not gain by the advance of mete- 

 orological science, and the future of aviation 

 will be largely determined by it. 



THE WORLD'S SUPPLY OF WHEAT 



According to a report issued to the Depart- 

 ment of Agriculture prospects for the world's 



