610 



SCIENGE. 



[N. 3. Vol. VII. No. 174. 



the details of construction of the kites and 

 of the meteorqgraphs. The second chapter con- 

 cerns the Results from the Kite Meteorographs and 

 Simultaneous Records at the Ground, and includes 

 complete tables containing data as to the alti- 

 tudes of the kites ; the temperature of the air 

 at the kite, on Blue Hill and in the valley 

 at the base ; humidity and wind velocity at the 

 kite and on the hill, etc. The third chapter is 

 by Mr. Clayton and is a discussion of the 

 records. If anyone has had any doubts as to 

 the scientific quality and as to the value of the 

 kite work done at Blue Hill, a glance at this 

 chapter will amply suffice to dispel his doubts. 

 A laborious collection of data and a careful 

 study of these data have clearly preceded the 

 final writing of this discussion. 



It would detain us too long were we to call 

 attention to the many noteworthy points which 

 Mr. Clayton has brought out. Only a few can 

 be mentioned. The anemometer records show 

 that between the average heights of 100 and 

 400 meters the rate of increase of velocity for 

 each 100 meters of greater altitude is 0.6 mile 

 per hour, this being a slower increase than has 

 been found to obtain in the cloud levels higher 

 up above the top of Blue Hill. The change in 

 direction of the currents aloft, shown by the 

 shifting of the kites during their ascents, is in- 

 teresting. The prevailing tendency is for the 

 kites to indicate currents from the west aloft, 

 no matter with what surface direction of wind 

 they left the ground. The temperature results 

 are naturally the most important. It appears 

 that the diurnal range of temperature diminishes 

 rapidly with increasing altitude in the free air, 

 and almost disappears, on the average, at 1,000 

 meters. 



The variations in change of temperature 

 with altitude are classified into six types, 

 all of which are striking. To mention only 

 three, type 4, which Mr. Clayton calls the warm 

 wave type, is produced when a warmer current 

 overflows colder air, and in a majority of cases, 

 when found below 2,000 meters, is caused by 

 the approach of a warm wave, which, moving 

 faster in its upper strata than in the lower, 

 overflows the colder air aloft before it is itself 

 felt as a warm wave on the earth's surface. 

 Such a type, when its existence is known, 



makes possible the forecast of a warm 

 wave with a high degree of certainty. 

 The cold wave type (type 5) shows a fall of 

 temperature with increase of altitude at the 

 adiabatic rate of unsaturated air, above 300 

 metres, while the night curve shows a rapid 

 decrease of temperatvire with increase of alti- 

 tude from the ground upward, these conditions 

 making it possible for showers to occur if the 

 lower air is damp enough. The connection of 

 tornadoes and thunderstorms with falls in tem- 

 perature is well known, and these results 

 throw much light on the vertical temperature 

 gradients at times of such disturbances. The 

 sixth type is, perhaps, the most interesting of 

 all. It shows the same or nearly the same tem- 

 perature from 400 to 1,400 metres or more, and 

 is found prevailingly in anticyclones. This is 

 of special importance because of its bearing on 

 the Hann, or driven, theory of anticyclones ; for 

 if, as generally stated, the warm and dry air at 

 considerable altitudes in anticyclones is the re- 

 sult of warming by descent and compression, the 

 vertical temperature gradient in anticyclones 

 should be at the adiabatic rate, or nearly at 

 that rate. No adequate explanation of these 

 apparent contradictions appears as yet, and 

 further temperature data from the free air in 

 anticyclones will be awaited with interest. 



The above are only a few of the many note- 

 worthy points which are brought out in this 

 valuable monograph. Meteorologists are under 

 a debt of gratitude to Mr. Rotch for his liberality 

 in conducting the experiments, and to Mr. Clay- 

 ton for the masterly way in which he has dealt 

 with the data under discussion. 



R. Dec. Ward. 



Harvard University. 



Outlines of Descriptive Psychology. By George 

 Trumbull Ladd. New York, Charles Scrib- 

 ner's Sons. 1898. Pp. xi-|-428. 

 The present volume covers substantially the 

 same field as the author's ' Psychology, De- 

 scriptive and Explanatory,' but is intended 

 rather as a text-book than as a treatise for ad- 

 vanced students. It is not a mere abridgment 

 of the former ; every point has been reviewed 

 and the expression revised, so that few sen- 

 tences read exactly alike in the two works. 



