POLAR YEAR EXPEDITION" — STAGG 117 



phone line as soon as the ice on the lake was safe for working on. 

 In the bush immediately behind the two stations the wire was hung 

 from the taller spruce trees bared of their longer branches, and on 

 the 8 to 10 miles of open lake, poles cut from spruce or birch trees 

 along the lakeside and let into the ice sufficiently far to be frozen 

 solidly in position, formed the bases of support. It was not prac- 

 ticable to lay the cable on the ice, partly because the high specific 

 inductive capacity of ice would have amounted to earthing the cable 

 as it became buried in the ice by its own weight, and partly because 

 a winter trail for Indians passes up the lake between the two sta- 

 tions. The cable would very probably have been inadvertently cut 

 by the passage of dog sleighs over it. In this work of cable laying 

 we all had a hand, but Mr. Stephenson with his experience of dog- 

 sleigh work gained in Greenland was invaluable in the open lake work 

 of providing the poles from the lakeside, and Mr. Grinsted looked 

 after all the technical details. Most of the erection was done at 

 temperatures between —5° C. and —15° C. ; it was a time of intro- 

 duction to the experience of minor frost bites for some of us. 



At the two stations the observers operating the cameras, designed 

 for auroral photography by Professors Stormer and Krogness of 

 Norway, were equipped with telephone headgear and breast-plate 

 microphones, supplied by Messrs. Siemens, Ltd., so that the hands 

 were free for manipulating the camera and plates. The microphones 

 were fitted with auxiliary diaphragms of cellophane supported over 

 the working diaphragm to prevent accumulation of hoar frost and 

 ice crystals obstructing its movement. These cellophane diaphragms 

 were exceedingly useful when working out-of-doors for periods of a 

 few hours at temperatures down to —35° C. 



Using the telephone system throughout the most rigorous winter 

 months, and taking turns at manning the substation, we continued 

 photographing aurora till the melting of the ice in spring undermined 

 the supports and finally allowed the whole line to break up. Alto- 

 gether we got about 4,700 pairs of photographs, of which probably 

 75 percent will be suitable for measurement. 



In addition to this side of the auroral work an almost continuous 

 log was maintained of all activity when it was dark enough to be 

 seen. It was not infrequent in midwinter for aurora to continue 

 uninterruptedly for 15 hours ; and, despite the fact that the winter of 

 the Polar Year was very near the minimum of the cycle of solar 

 activity, aurora was observed at some time on every night almost 

 without exception during the autumn, winter, and spring months 

 when sky conditions were suitable. 



During our 15 months' stay at Rae we had frequent contact with 

 the outside world ; indeed by wireless it could have been made con- 

 tinuous. In 1930 a reputedly rich discovery of gold and pitchblend 



