GOOD BY TO MARVIN 249 



even full, when it was covered with the glass horizon 

 roof. 



Marvin, then lying full length upon his face, with 

 his head to the south and both elbows resting upon the 

 snow, was able to hold the sextant steady enough to 

 get his contact of the sun's limb in the very narrow 

 strip of the artificial horizon which was available. A 

 pencil and open note-book under the right hand offered 

 the means of noting the altitudes as they were obtained. 



The result of Marvin's observations gave our posi- 

 tion as approximately 85° 48' north latitude, figuring 

 the correction for refraction only to a temperature 

 of minus 10 F., the lowest temperature for which we 

 had tables. It was from this point that, reckoning 

 twenty-five miles for our last two marches, we calcu- 

 lated the position of Camp 19, where Borup turned 

 back, as being 85° 23', as against our respective dead 

 reckoning estimates of 85° 20', 85° 25', and 85° 30'. 

 This observation showed that we had thus far averaged 

 eleven and a half minutes of latitude made good for 

 each actual march. Included in these marches had 

 been four short ones resulting from causes the recur- 

 rence of which I believed I could prevent in future. 

 I was confident that if we were not interrupted by open 

 water, against which no calculations and no power of 

 man can prevail, we could steadily increase this aver- 

 age from this time on. 



The next march was made in a temperature of minus 

 thirty and a misty atmosphere which was evidently 

 caused by open water in the neighborhood. About 

 five miles from camp we just succeeded by the liveliest 

 work in getting four of our five sledges across an open- 



