BAROMETER TO SEA LEVEL. V 



and the table may be calculated from tbe value of ^ in the same 



way as when Table A is employed. 



A table for reducing the barometer to sea level is furnished from 

 the Central Office, Toronto, to each station in connection with the 

 Meteorological Service of the Dominion. 



Formerly these were computed directly from formula iii. (using 

 a slightly different constant from that given above.) The accom- 

 panying tables were recently calculated to diminish the labour of 

 computation. 



In Canada, no reduction for height is applied to the observed 

 temperature of the air; as, although some correction might be of 

 advantage, it is by no means certain that a correction, obtained from 

 observations on a mountain, would be suited to a station on an 

 elevated table-land. The correction, if it were applied, would, how- 

 ever, be very small at nearly all our stations. 



I hope to discuss, more fully, on some future occasion the question 

 of the necessity for a correction to the observed temperature of the 

 air in reducing barometric readings. 



