250 JOURNEY TO THE SHORES 



47° below zero, with no portion of the fluid 

 in the upper part of the tube, was let down 

 slowly into the water, but drawn cautiously 

 and rapidly up again, when a red drop at 

 + 42° indicated that the fluid had risen to 

 that point or above it. At this period the 

 daily visits of the sun were very short, and 

 owing to the obliquity of his rays, afforded 

 us little warmth or light. It is half-past 

 eleven before he peeps over a small ridge 

 of hills opposite to the house, and he sinks 

 into the horizon at half-past two. On the 

 28th Mr. Hood, in order to attain an ap- 

 proximation to the quantity of terrestrial 

 refraction, observed the sun's meridian alti- 

 tude when the thermometer stood at 46° 

 below zero, at the imminent hazard of hav- 

 ing his fingers frozen. 



He found the sextant had changed its 

 error considerably, and that the glasses had 

 lost their parallelism from the contraction 

 of the brass. In measuring the error he 

 perceived that the diameter of the sun's 

 image was considerably short of twice the 

 semi-diameter ; a proof of the uncertainty 



