May 8, 1903.] 



SCIENCE. 



753 



the theory of the general circulation of the 

 atmosphere as put forward by Ferrel and 

 Thomson, and as adopted in all the newer text- 

 hooks, that it seems well to give here a trans- 

 lation of Dr. Hildebrandsson's summary (pp. 

 47^8 of the report) : 



" By means of direct observations the fol- 

 lowing results have been obtained: (1) 

 Above the heat equator and the equatorial 

 calms there is, throughout the year, a cur- 

 rent from the east which seems to have very 

 high velocities at great altitudes. (2) Above 

 the trades there is an anti-trade from S. 

 W. in the northern, and from N. W. in the 

 southern hemisphere. (3) This anti-trade 

 does not extend beyond the polar limit of the 

 trade; it is deflected more and more to the 

 right in the northern, and more and more to 

 the left in the southern hemisphere, and finally 

 becomes a current from the west above the 

 crest of the tropical high pressure belts, where 

 it descends to supply the trades. (4) The dis- 

 tricts at the equatorial margin of the trades 

 are partly in the trades and partly in the equa- 

 torial calms, according to the season. Above 

 them there is, therefore, an upper monsoon: 

 the anti-trade in winter, and the equatorial 

 current from the east in summer. (5) From 

 the tropical high pressure belts the air pres- 

 sure on the whole decreases continuously to- 

 wards the poles, at least to beyond the polar 

 circles. Further, the air of the temperate zone 

 is drawn into a vast ' polar whirl ' turning 

 from west to east. This whirling movement 

 seems to be of the same nature as that in an 

 ordinary cyclone: the air of the lower strata 

 approaches the center, while that of the higher 

 strata tends out from the center, and this out- 

 ward tendency increases with the altitude 

 above sea level as far up as the greatest alti- 

 tudes from which we have observations. (6) 

 The upper currents of the atmosphere in the 

 temperate zones extend over the tropical high 

 pressure belts, and descend there. (7) The 

 irregularities which are noted at the earth's 

 surface, especially in the regions of the Asian 

 monsoons, as a whole disappear at the lower 

 or intermediate cloud levels. (8) We must 

 entirely abandon the notion of a vertical cir- 

 culation between tropics and poles which has 



up to this time been accepted in accordance 

 with the theories of Ferrel and Thomson." 



This ' vertical circulation,' to which allusion 

 is made, refers to the view that the air, ascend- 

 ing near the equator, flows as an upper cur- 

 rent across the tropical high pressure belts to 

 the circumpolar regions, and thence returns as 

 an intermediate current from the poles to- 

 wards the equator. It is in regard to this 

 point that the conclusions of Dr. Hildebrands- 

 son are most interesting. Dr. Hildebrands- 

 son expressly states that he simply presents 

 facts, and does not discuss theories. But he 

 does say most emphatically (p. 44) : " II faut 

 done abandonner une fois pour toutes cette 

 idee d'une circulation verticale entre les trop- 

 iques et les poles, — circulation qui semble du 

 reste impossible pratiquement dans une couche 

 dont I'epaisseur est tres petite en comparison 

 avec les distances horizontals. Esperons que 

 des a present ces ' courants polaires ' et 

 ' equatoriaux,' qui ont fait tant de confusion 

 dans la meteorologie dynamique, disparaitront 

 enfln completement de la science meteorolo- 

 gique, au moins dans le sens dans lequel on 

 les a adoptes jusqu'iei." E. DeO. Waed. 



THE LIGHT OF NOVA GEMMORTJM. 

 The light of ISTova Gemmorum appears to 

 be fluctuating like that of Nova Persei No. 2. 

 On the evening of May 1 it appeared that its 

 light had increased about half a magnitude 

 during the preceding twenty-four hours. 

 Since the measures described in the Astro- 

 nomical Bulletin of April 22, similar measures 

 were obtained on April 24, 25, 27, 28, 29, 30 

 and May 1, and gave the magnitudes 9.37, 

 9.67, 9.71, 9.81, 9.61, 9.76 and 9.26 respectively. 

 Edward C. Pickering. 



BRAIN-WEIGHT, CRANIAL CAPACITY AND 



THE FORM OF THE HEAD, AND THEIR 



RELATIONS TO THE MENTAL 



POWERS OF MAN. 



Dr. H. Matiegka, in Part I. of his extensive 



studies on this subject,* has published some 



* ' Ueber das Hirngewicht, die Schadelkapacitat 

 und die Kopfform, sowie deren Beziehungen zur 

 psychischen Thiitigkeit des Menselien,' Sitgb. d. 

 Jcon hohin. Ges. d. Wiss., II. Classe, Article XX., 

 1902. 



