II. NOTES ON THE METEOROLOGICAL INSTRUMENTS AND THEIR 



EXPOSURE. 



BY 



LIEUTENANT C. ROYDS, R.N. 



WITH ILLUSTRATIONS OF SOLAR PHENOMENA AND CLOUD 



OBSERVATIONS. 



BY 



DR. E. A. WILSON. 



METHOD OF TAKING OBSERVATIONS AT SEA. 



ON the port side of the Upper Deck, under the bridge and in a small alley way, through which there WHS 

 free circulation of air, was hung the meteorological screen, in which were placed the Dry- and Wet-Bulb 

 Thermometer and the Maximum and Minimum Thermometers. The Barometer was hung in the lobby 

 leading down into the Ward Eoom. 



Observations were taken by the Officer of the Watch every two hours, when possible, and always at the 

 end of the watch, and were entered in the rough book supplied for the purpose. Water temperatures 

 (surface) were also taken, the water being drawn by means of a canvas bucket from the bridge. The 

 thermometer was immersed in it, left for a few moments, and then read. 



Winds and direction of cloud-movement were taken by the Compass and are entered as magnetic. The 

 latter observation at sea is difficult owing to the motion of the ship. The Maximum and Minimum 

 Thermometers are also affected by the same cause, and, when the motion is excessive, erroneous readings 

 must occur. 



METHOD OF TAKING OBSERVATIONS IN WINTER QUARTERS. 



Until the sea was frozen over, after our arrival in winter quarters, the same system of observing was 

 used as at sea. As soon as the sea was frozen over, a meteorological screen was set up on the ice, about 

 120 yards astern of the ship, so as to be well clear from any effects which the ship might cause, except in 

 westerly winds, which did not occur (figs. 1 and 2). 



Facing the, E.N.E. was placed a screen enclosing the Thermograph and Hygrograph. The screen with 

 the Dry- and Wet-Bulb and the Maximum and Minimum Thermometers was hung facing W.S.W., about 

 4 feet from the ground. There was also another screen in which another Thermograph and Hygrograph 

 were placed. 



A wind vane was made on board the ship and placed about 12 feet from the ground, being set up true ; 

 all winds taken in winter quarters are logged as True Winds. The Robinson Anemometer was set up 

 about 15 feet from the ground; the instrument we called "Dines" small Anemometer was set up with its 

 head about 10 feet above the level and with about 5 feet of tubing to the recording part. Observations 

 were taken, with hardly a break, every two hours, night and day by the Officers, assisted at times by the 

 four Quarter-masters and by the assistant Cook, from April, 1902, to November, 1903. It is due to the 

 conscientious care shown by each observer, and the unselfish interest they all took in the work, that the 

 record is as complete as it is. 



The question of a lamp for taking the observations at night, and when the Sun is below the horizon 

 during the Winter, is one for very careful consideration before the ship leaves the home port. For a time 

 we used a small electric lamp, but this necessitated taking out a heavy battery, so a candle lamp was 

 made which worked well and seldom blew out, even in the strongest winds. 



