282 



Arboretum Britannicuin. 



fault with such indefinite terms, I would propose to state the velocity in 

 miles per hour. The direction ought also to be accurately noted. 



Falls of rain or melted snow should also be noted in inches and decimals. 

 The mean temperature of the day during a storm should also be registered ; 

 and it may be found by the mean of daily observations at 10 a.m. and 

 10 P.M. with an ordinary thermometer ; or at the mean of the daily ex- 

 tremes, by Six's thermometer, or by what is called a night-and-day ther- 

 mometer ; the difference between the two modes will not exceed a small 

 fraction of a degree in twelve months. Stormy phenomena occurring 

 within the month may be expressed in the following tabular form : — 



Phenomena of Winds. 



si 

 li 



2 



°^ 



3 



n 



CO) 



E£ 



■2 BO 



eg 



1^ O 



SSS 







c 



o 



1 

 3 



^S5 



1" 



(5 



















This table should be accompanied with a brief summary of the ordinary 

 phenomena of the weather for the tv/o months, in popular and concise lan- 

 guage, from each place ; in which the periods at which the winds shifted, 

 the extraordinary fluctuations of temperature arid atmospheric pi*essure, 

 duration of clouded or clear atmosphere, and the mean temperature and 

 mean height of the barometer for every ten days during each two months, 

 should also be noticed. By attending strictly to the recording of the mean 

 temperature at Southampton, at Howick, and at Annat Gardens, a question 

 interesting to meteorologists, and to those interested in the progress of 

 vegetation, respecting the mean tempera,tures of different places, woiild be 

 solved; It is the opinion of many, too, that a simultaneous fluctuation in 

 atmospheric pressure takes place over a considerable breadth of the earth's 

 surface : our remarks may tend to confirm that opinion. As both pheno- 

 mena are affected by the height of the place of observation, that elevation 

 above the sea should be noted. I would propose that our observations 

 commence on the first day of March, and be sent for publication in your 

 June Number, on the first day of May, and regularly every two months 

 afterwards. It may be unnecessary to say, that correctness of meteoro- 

 logical instruments, accuracy of observation, and punctuality of communi- 

 cation, are indispensable requisites in the undertakings I am, Sir, yours, &c. 

 ■ — Archibald Gorrie. Annat Garde7is, Feb. 23. 1831* 



Art. IV. Tlie Arboretum Britannicuni. 



EespECTING your intended " Arhoretum Britannicuni " I have a ^evf re^ 

 mai'ks to inake, which, for want of time I could not before commit to 

 paper. The work promises to be a most useful and interesting one, but a 

 most laborious undertaking. I particularly like the idea of giving figures 



