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



a result totally irreconcileable with the phaenomena observed, and 

 sufficient to disprove (so far as in the face of the analytical difficulties 

 it presents can be disproved) the whole theory of secondary waves. 



If it be contended that Fresnel's integrals are correctly deduced, I 

 reply that they are so only by taking into account other terms in the 



values of the sine and cosine of the arc — . . s% besides those 



K 2ar 



in which s rises to the second power, and which we are not entitled 



to do. 



For the effect of taking into account such additional terms must 

 be either sensible or insensible. If it is sensible, we are not justified 

 in leaving out of consideration similar terms in calculating the value 

 of/; if the effect is insensible, there is an end of Fresnel's explana- 

 tion. 



I purpose to advert, in a future paper, to other points in this im- 

 portant subject. 



Liverpool, December 18, 1844. 



X. Report on the Meteorology of Toronto in Canada. 

 By Lieut.-Colonel Edward Sabine, R.A., F.R.S.* 



THE subject which I am about to bring before the Section consists of a 

 portion of the results of the meteorological observations which have been 

 made at the magnetical and meteorological observatory at Toronto in Canada, 

 in the first two years of its establishment. It is well known to the members of 

 the Section, that in conformity with the recommendation made by this 

 Association, the British Government has formed establishments in various 

 parts of the globe, for the purpose of making magnetical and meteorological 

 observations on a systematic plan, and has created a department for the re- 

 duction and publication of the observations. As the officer entrusted with the 

 conduct of these operations, I regard it as not less a duty than a pleasure, to 

 communicate, from time to time, at the meetings of the British Association, 

 such of the arrangements, or of the observations themselves, or of the conclu- 

 sions to which they may have led, as I may suppose may be interesting to its 

 members. I have accordingly selected for the present occasion some portion 

 of the results which the meteorological observations at Toronto, in 1841 and 

 1842, have yielded, when subjected to a full process of reduction, and care- 

 fully examined. I have preferred the meteorological to the magnetical ob- 

 servations, partly on account of the more popular character of the subject 

 generally, and partly because the conclusions to which the meteorological 

 observations have already conducted appear to possess a completeness and 

 fullness not yet attained in magnetism. The observations, which will be treated 

 of in this communication, were made at every second hour throughout the 

 year, except on Sundays, Christmas day, and Good Friday. Subsequently to 

 the period which will be now passed in review, they have been made hourly, 



* Comnuinicatecl to the Mathematical and Ph3'sical Section of the British Asso- 

 ciation for the Advancement of Science, at the York meeting, 1844. 



