SNOW-GOGGLES 87 



in Christiania. They were excellent little compasses, 

 but unfortunately useless in cold weather that is to 

 say, when the temperature went below - 40 F. ; at 

 this point the liquid froze. I had drawn the maker's 

 attention to this beforehand and asked him to use as 

 pure a spirit as possible. What his object was I still 

 do not know, but the spirit he employed was highly 

 dilute. The best proof of this was that the liquid in 

 our compasses froze before the spirits in a flask. We 

 were naturally inconvenienced by this. Besides these 

 we had an ordinary little pocket-compass, two pairs of 

 binoculars, one by Zeiss and the other by Goertz, and 

 snow-goggles from Dr. Schanz. We had various kinds 

 of glasses for these, so that we could change when we 

 were tired of one colour. During the whole stay on 

 the Barrier I myself wore a pair of ordinary spectacles 

 with yellow glasses of quite a light tint. These are 

 prepared by a chemical process in such a way that they 

 nullify the harmful colours in the sun's rays. How 

 excellent these glasses are appears clearly enough from 

 the fact that I never had the slightest touch of snow- 

 blindness on the southern journey, although the spec- 

 tacles were perfectly open and allowed the light to enter 

 freely everywhere. It will perhaps be suggested that I 

 am less susceptible to this ailment than others, but I 

 know from personal experience that such is not the 

 case. I have previously had several severe attacks of 

 snow-blindness. 



