Meteorology- 471 



cyon days seem really to have set in this year, and to have be- 

 <)-un on the very day stated in the Roman Calendar as Dies 

 Alci/onii*, for last night the change of weather took place. 



Dec. 16. — The Halcyon days continue to afford pleasant 

 weather for winter, the air being calm and mild. The Sweet 

 Coltsfoot is in full flower all over the garden ; for I find that 

 this species increases with me so as to become a terrible weed, 

 whereas the White Coltsfoot seldom becomes troublesome by 

 its increase. The Laurestine Viburnum Tinus in flower. 



j) eCt 17. — Mr. 13. M. Forster discovered Agaricus violaceus 

 in the garden today, which is unusually late in the year. 

 This is the species called Blewits or Waterflaps. The spe- 

 cimen found today was of an unusually pale colour, and rather 

 buff than violaceous. 



METEOROLOGY. 



To the Editors of the Philosophical Magazine and Journal. 

 Gentlemen, 



In order to reply to Dr. Burney's letter in your last Num- 

 ber, I have looked over my Journal, and find the observation 

 on the barometer on the morning of the 12th of October, is 

 put down 29-75 ; and although 1 have for eight years been in 

 the constant habit of noting down the indications of the se- 

 veral instruments, I will not be positive that it is in this in- 

 stance correct, on the contrary, as the morning was stormy, I 

 am inclined to think with Dr. Burney, that there is an error, 

 and that it should be 28'75. In looking over my observa- 

 tions for the last eight years, I find that the barometer has 

 sometimes stood as high as 30'0 during a storm, but this is 

 unusual. 



I am of opinion that the observations are most valuable, 

 when taken simultaneously. I am also of opinion, that it 

 would tend materially to elucidate Meteorological Science, if 

 some scientific person in Scotland f would undertake to make 

 observation simultaneously with us. I understand the ther- 

 mometer in Scotland, a week or two since, was as low as 16. 



Boston, 25th Dec. 1824. Yours &c. Samuel Veall. 



to notice the following curious fact,— that when the kite on mounting very 

 high acquired a different direction from getting into a different current of 

 air the wind usually blew from the same quarter on the earth's surface be- 

 fore the expiration of24 hours. Thus the changes of the wind seem to take 

 place first in the higher regions of the air. and are propagated downwards.^ 

 1 have confirmed this experiment, and established the fact, by the use of 

 small air balloons, but the kite answers the purpose quite as well. 



• See Perennial Calendar, or Companion l<> tin- almanack, i. vol. 8vo. 

 (Published hv Harding and Co. Finsbury Square,) lH'i;{, under Dec 12. 



f See a Meteorological Register for 1M»':>, in our present Number, kept 

 in the northernmost part of Scotland. 



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