330 SCIENTIFIC RECORD FOR 1884. 



height of 50 feet), by means of kites extending up to 1,500 or 2,000. Vox 



V n 



the formula — =.p- given by Stevenson, which should not be used 

 V u 



above 100 feet, Mr. Archibald suggests the following: -—=4 /5 



V V h 



■which is one of Stevenson's first formulae. This holds good up to 23,000 



feet if we may rely upon the observations of Vettin, and does not vary 



very much from the formula given by Ferrel, viz : 



_ 0.0027 P ^ 



^ 1X0.003G(J5< P'"^ 



(Nature^ xxvii, pp. 243-507.) 



247. Mr. Thomas Stevenson, of Edinburgh, replies to Mr. Archibald's 

 remarks and maintains that his own second formula is abundantly suf- 

 ficient to represent the observed increase of wind velocity. {Nature, 

 XXVII, p. 432.) 



248. A. Buclian communicates the results of the Challenger observa- 

 tions as to the diurnal velocity of the wind on the ojjen sea near the 

 shore and on land. These results are also incorporated in his article on 

 Meteorology in the Encyclopcedia Britannica. {Nature, xxvii, p. 413.) 



249. Mr. E. D. Archibald differs from Buchan in the latter's explana- 

 tion of the diurnal variation in the variation of the wind, and affirms his 

 adherence txD the views of Espy and Koppen. {Nature, xxvii, p. 461.) 



250. W. Koppen criticises some passages in Hann's Climatology rela- 

 tive to land and sea breezes, and his remarks suggest the importance of 

 a few additional observations in favorable localities ; thus he says the 

 origin of the sea breeze is not primarily due to the increase of pressure 

 in the upper part of a warming column of air. Since the sea breeze be- 

 gins over the sea and subsequently stretches to the land and up into 

 the bays and inlets, this must be attributed to the resistance of the laud 

 retarding the breeze which is felt at a little distance out over the sea and 

 is first overcome when the pressure increases to a certain limit. 



Koi^pen thinks that since the sum total of the ujiper and lower circu- 

 lation is certainly stronger by day than by night, and as the land breeze 

 is feebler than the sea breeze, it is not necessary to conclude that a land 

 wind is blowing strongly at some altitude above the earth's surface. 

 He calls attention to the fact that although the sea breeze is generally 

 intensified when the prevailing wind direction agrees with it, yet, on 

 the other hand, observation does not confirm the idea that the land 

 wind is increased when the prevailing winds agree with it. This rever- 

 sion of the i)receding law is an apparently natural one, and is, per- 

 haps, generally supposed to be true, but, as Koppen remarks, actual 

 observations do not confirm it, and we evidently still need a correct 

 explanation of the mechanism of the sea breeze. {Z. 0. G. M., xix, p. 39.) 



251. [Is not this explanation suggested by the above note on the re- 

 sults of Profess Dr Upton's study of a ship's velocity in the South Pacific 

 Ocean, i. e., the level of uniform maximum velocity is much lower over 



