60 



REPORT 1844. 



Convenient hours of observation. 



For mean values, 8 p.m. mean time (precise) ; which at Toronto gives the 

 following approximation : viz 



f Temperature 44*1 Mean annual value 4<4'*4 



At 8 P.M. at J If "°"^'y •. ^^'l,. » » 78-0 , 



Toronto < Vapour tension -25/ „ „ -259 



loionio. I Barometric pressure , . 29-605 „ „ 29-608 



[^ Gaseous pressure 29-345 „ „ 29-349 



For maxima and minima. 



From 4 to 6 a.m., for minimum of temperature and tension of vapour, and for 



maximum of humidity and gaseous pressure. 

 From 2 to 4 p.m., for maximum of temperature and tension of vapour, and 



for minimum of humidity and gaseous pressure. 



I have now only to apologize to the Section for the length of time that I 

 have occupied them, and to thank them for their patient attention. 

 York, September 27th, 1844. 



Postscript, Woolwich, Nov. 30. 



After the preceding pages were printed, I received from Mr. Airy the 

 volume of the Greenwich magnetical and meteorological observations for 

 1842, in which the meteorological reductions have been made in almost 

 exactly the same form a-s those of Toronto. The volume was accompanied 

 by a suggestion from the Astronomer Royal, that it might increase the interest 

 of this communication, if 1 were to add a few words by way of appendix, 

 showing the points of similarity or dissimilarity in the results at the two 

 stations. I have much pleasure in adopting this suggestion, and in availing 

 myself of Mr. Airy's permission to do so ; for I have had great satisfaction 

 in noticing the very remarkable similarity which prevails in the results at 

 Greenwich and Toronto, with reference to several points which have been 

 the objects of especial notice in the preceding discussion. In the diurnal 

 variations of the elastic force of the vapour, — of the gaseous pressure, — and 

 of the force of the wind, — the evidence of a direct dependence on the diurnal 

 march of the temperature is fully as striking at Greenwich as at Toronto, as 

 will be seen by the following synopsis : 



Synopsis of the Diurnal Variations at Greenwich. 



