ON THE METEOROLOGY OP TORONTO IN CANADA. 



61 



At Greenwich the force of the wind is estimated at each observation hour 

 in numbers varying within the limits of to 6. At Toronto the estimation 

 is in lbs. pressure on a square foot of surface kept perpendicular to the 

 current. In single instances the scales are comparable, because the square of 

 the number expressing the force at Greenwich corresponds approximately to 

 the pressure in lbs. avoirdupois. But the comparability of the scales does 

 not hold good when the sums of the forces and the sums of the pressures are 

 taken. The sums of each are however comparable inter se, and show the 

 hours of maximum and minimum force, and the regularity of the progression. 

 The registry of the anemometer at Greenwich shows that the pressure of the 

 wind is more than doubled in its mean diurnal range. 



The following table exhibits the differences at the several observation hours 

 of Greenwich and Toronto, of the temperature, of the vapour pressure, and 

 of the gaseous pressure, from their respective mean yearly values. The sign 

 + signifies above the mean value of the year, and — below it. 



The mean monthly values of the vapour pressure, and of the gaseous press- 

 ure at Greenwich exhibit also the same correspondence with the variation of 

 the temperature in the different months of the year as at Toronto. 



Synopsis of the Annual Variation of the Temperature, Vapour pressure, and 

 Gaseous pressure at Greenwich. 



