Lieut.- Col. Sabine's Report on the Meteorology of Toronto. 95 



and the results of these may possibly be brought before the Section on a 

 future occasion. 



For the purpose of rendering this communication more interesting and 

 more useful, I have compared the meteorological results obtained at Toronto 

 with those obtained by M. Kreil at the magnetical and meteorological obser- 

 vatory at Prague in Bohemia*. It is frequently found that we gain more by 

 such comparisons, — by the points of resemblance and points of difference, 

 and by the analogies and contrasts which they bring to our notice, — than we 

 do by a simple direct investigation. 



Prague like Toronto is situated at a considerable distance from the ocean 

 (between 300 and 4-00 miles) in the interior of a great continent, the latitude 

 and elevation moreover not being very dissimilar. The agreement which 

 will be shown in the leading features of their meteorology manifests that 

 these features belong to a locality so circumstanced, whether the continent 

 be Europe or America ; whilst the minor differences point to climatological 

 distinctions of a secondary order, important indeed to discuss from their 

 bearing on the health and occupations of mankind, as well as in more purely 

 scientific respects, but into which time will scarcely permit me to enter on 

 the present occasion beyond a mere notice of some of the facts. 



In all comparisons between places situated in Europe and in North Ame- 

 rica, there is one leading difference in respect to temperature which we must 

 expect to find, which is doubtless familiar to all the members of the Section, 

 viz. that in Europe we enjoy a climate of higher mean temperature in pro- 

 portion to the latitude than is the case in America ; in other words, that the 

 isothermal lines descend into a lower latitude in America than they do in 

 Europe. It would occupy far too much time to discuss, on the present occa- 

 sion, the causes of this great climatological difference ; they have been largely 

 discussed by many eminent philosophers ; but it may be well, before we pro- 

 ceed to further details, to notice briefly the amount of difference in this re- 

 spect which is shown by the observations at Prague and Toronto. 



The following statement exhibits the particulars of the latitude, elevation 

 above the sea, and mean temperature of the two stations ; as well as the cor- 

 rection of the difference of their mean temperatures on account of difference 

 of elevation : — 



Toronto, latitude 43° 39' Elevation 330 feet. 



Prague, „ 50 05 „ 582 „ 



Difference 6 26 Difference 252 



Prague should be colder on account of its elevation . 0°'8 Fahr. 



Mean temperature, Toronto 44 "'^ 1 -pv-^. . .„ 



„ Prague . 48 '7 1 J ^ ^rence . . . 



Difference of temperature corrected 1 r» r i 



/. ..a. V 1 *• > Prague warmer 5 •! 



lor difference of elevation . . 



> Pragi 



Whence it appears that Prague is 5°'l warmer than Toronto, although its 

 latitude is 6° 26' more distant from the equator. 



TEMPERATURE. 



We will now proceed to the distribution of the mean temperature into the 

 several hours of the day, and into the several months of the year ; the first, 

 forming the diurnal variation of the temperature, or that variation which has 

 a day for its period ; the second, the anntial variation, or that variation which 

 has a year for its period. 



Diurnal Variation. — The diurnal variation is the well-known consequence 



* Mag. und Met. Beobachtungen : Prag. 1839-1842. f Kreil, Jahrbuch fiir 1843. 



