VOYAGE OF THE SCOTIA, 1903-1904. 



Ill 



Temperature of the Air. — Thermometers, Hygrometers. 



The Expedition started with an ample supply of thermometers, but as very few 

 were broken, it is unnecessary to give the corrections of those not used. The following 

 are the corrections. It will be seen that they are very small. 



The form of thermometer screen employed for sea observations was the small 

 single-louvred pattern recommended by the Meteorological Office. There was one on 

 the starboard and one on the port side of the ship, screwed to posts which projected 

 clear of the vessel, so that the air could circulate freely around the thermometers. The 

 height above the deck was five feet and above the sea seventeen feet. The thermometers 

 in both boxes were read at each observation, and the readings of the instruments exposed 

 on the weather side were entered in the log. Except on rare occasions, one side of the 

 ship was definitely a weather and the other a lee side. It may be worthy of notice 

 that there was usually a difference of one or two degreees between the weather and the 

 lee side of the " Scotia," the instrumental readings on the lee side being affected by 

 heated currents from the cabins and engine-room, — hence the importance of having the 

 thermometer screens on both sides of the poop. On one occasion the lee side was as 

 much as 5° warmer than the weather side, and on another occasion, during a calm, a 

 difference of nearly 10° was noted. 



The wet i»ulb thermometers had a fresh coating of muslin put on them about once a 

 week, and daily the bulbs were syringed with filtered water to get rid of the saline 

 accretions such as form on all surfaces exposed to the action of sea-spray. A large and 

 small Richard thermograph and a Richard hair hygrograph w-ere hung on Richard 

 suspensions on the weather side. 



Clouds. 

 The amount of cloud is estimated on the usual scale — clear blue sky ; to 10 entirely 

 overcast. 



