CONTRtBtJTIONS TO METEOROLOGY. 265 



12.214 inclies, and is the most rainy July on record. The amount of 

 rain which fell in the month of August was less than the usual mean 

 quantity for that month. 



Snow fell on 46 days, amounting to 58.96 inches in depth ; it was 

 snowing 281 hours, 30 minutes ; this amount shows a decrease equal 

 to 36.80 inches compared with the mean amount of a series of years. 

 February and December were the months which showed the greatest 

 amount of snow. The first snow of the season fell on the 4th of 

 November, and the last snow of spring fell on the 21st April. 



Evaporation. — The amount of evaporation from the surface of water, 

 during the seven months which the observations are recorded (owing 

 to the presence of frost) amounted to 18.730 inches, which is 1.515 

 inches less than the amount of last year. July indicated about 1 inch 

 less than the usual amount ; the amount of ice evaporated during the 

 remaining months of the winter season showed about the usual average 

 amount. 



Wind. — The most prevalent wind during the year was the N.E. by E, 

 The next in frequency the W. by N., and the least prevalent the S^ 

 The aggregate amount linear in miles run was 41,338.60 miles, which 

 «hows a decrease of 13,086.50 miles compared with last year, and a 

 decrease of 11,723.03 miles compared with 1856. The yearly mean 

 velocity was 4.613 miles per hour, which is 1.567 miles less than the 

 mean annual velocity for 1857. The maximum velocity was 37.70 

 miles per hour. January was the most windy month, and September 

 the calmest. 



The greatest Intensity of the Sun's Bays was 117°, and the lowest 

 point of terrestrial radiation, 3F.2 below zero. 



The yearly amount of Bew was considerably below the usual mean 

 amount compared with a series of years. 



There were 56 days perfectly cloudless, which is 25 more than the 

 cloudless days of 1857. There were 118 nights suitable for astronomi- 

 cal purposes. 



The Aurora Borealis was visible at observation hours on 39 nights. 

 Lunar Haloes were seen on 4 nights. The Zodiacal Light was very 

 bright in February, but since then has exhibited no special appearance. 

 Parhelia were visible on 2 days. 



The Eclipse of the Moon was visible on the 27th February. The 

 Eclipse of the Sun was invisible on the 1 5th March owing to cloudy 

 weather. 



