698 MR ROBERT COCKBURN MOSSMAN ON 



temperature is in progress, the increase being unequally partitioned between the day 

 and night values, the maximum temperatures rising more rapidly than the minima. 



April. 



Low pressure prevails at the beginning of the month, during the continuance of 

 which polar winds blow with diminished frequency. An interruption in the vernal rise 

 of temperature known as the borrowing days occurs about the 10th, the fall of tempera- 

 ture being greater during the night than during the day, pointing to increased terres- 

 trial radiation. At this time pressure is high, winds from the N.E. and E. being at a 

 temporary maximum, while those from S., S.W., and W. are well below their mean 

 frequency. Snow and hail showers exhibit a decided rise after the 5th. Throughout 

 the last three weeks pressure is high, except for a slight fall culminating on the 21st, 

 which is accompanied by a considerable rainfall, while gales shoot up to their average 

 annual frequency, thereafter to remain steadily below it for four and a half months. 

 During the prevalence of the strong winds, fog is uncommon. After the 21st, pressure 

 rises rapidly, hail showers increase with the N.W. winds which usually blow in the rear 

 of a cyclonic disturbance. A rapid fall of temperature also occurs. Westerly winds 

 fall to their annual minimum about the 26th. 



May. 



Pressure is well above the mean during the first fourteen days, after which it falls 

 quickly till the 18th, showing an equally rapid recovery in the four days immediately 

 succeeding. E. and N.E. winds are at their annual maximum about the 10th of the 

 month, pressure being then very high, although the rainfall is considerable. A slight fall of 

 temperature occurs at this time. Fog now becomes frequent, thunderstorms also showing 

 an increase, but hail showers are few, the values falling permanently below the annual 

 mean at the close of the month. Rainfall is, on the whole, below the average, sunshine 

 being abundant, except during a period of low pressure about the 15th. Temperature 

 rises rapidly after the temporary interruption about the 10th. 



June. 



Pressure is high throughout the month, the anti-cyclonic tendency being at a 

 maximum. Thunderstorms now become comparatively frequent, while the prevailing 

 easterly winds bring with them an increased amount of fog. E. winds diminish some- 

 what from the 2nd to the 9th, after which there is little variation. The daily range of 

 temperature reaches the annual maximum on the 20th, the increased difference between 

 the day and night values being almost entirely due to the higher day temperatures 

 which occur at this time. From the 20th to the 24th the maxima show a decided fall 

 and the minima a less marked one ; in other words, there is a distinct tendency for cloudy 

 weather about this time. At the end of the month another well-marked fall of tempera- 

 ture takes place, during an increase in the frequency of N.E. and E. winds. The 



