Sir D. Brewster on the Law of Daily Temperature. 349 



The coincidence between the observed and calculated re- 

 sults, as shown in this table, is so remarkable, that the -para- 

 bolic temperatures, as we may call them, never differ from the 

 real temperatures more than one quarter of a degree of 



FAHRENHEIT. 



Since we began this article we have been favoured by Ro- 

 bert Thorn, Esq., of Ascog, a gentleman of great scientific 

 attainments, with the results of an hourly meteorological re- 

 gister, which he kept for twelve consecutive years at Rothesay 

 in the Isle of Bute, and which we have no scruple in saying 

 forms the most important class of meteorological observations 

 which have ever been made, not only for their number and 

 continuity, but from the care and attention with which they 

 were conducted. These observations possess also another 

 interest, in so far as they exhibit the laws of temperature on 

 the west coast of Scotland, and in a climate essentially differ- 

 ent from that of the east coast, to which our Leith and Inver- 

 ness observations relate. Our limits will not permit us to 

 give the results of these observations so fully as we could wish, 

 but we shall endeavour to lay the most important of them 

 before our readers. The following are the times of mean tem- 

 perature: — 



Mean of twelve years, 

 from 1828 — 1832 inclusive. Distances from noon. 



Mean temp, at 8 h. 32 m. a.m. 47°-46 3 h. 28 m. 



7 39 p.m. 47°'46 7 39 



Critical interval 11 h. 7 m. 



Hence it appears that the hours of mean temperature are 

 much earlier than at Leith, and are nearly the same as those 

 at Inverness, differing from them only by four minutes in the 

 morning and five minutes in the evening, while the critical 

 interval differs from that of Inverness only nine minutes. 



The similarity between these two sets of observations will 

 appear still more striking from the following law of the homo- 

 nymous hours : — 



Mean difference 0*348 



