I902] TIDAL OBSERVATIONS 207 



become too firmly gripped by the ice. As the wire was strong 

 enough to admit of comparatively heavy weights, I had hopes 

 that the pull would always be sufficient to overcome the fric- 

 tion of the ice, and for a long time this was so ; but at length 

 the ice became thick enough to hold the wire, and then of 

 course the arrangement failed. 



We had already improved on the tripod, by fixing up a 

 second gauge working over the ship's side, with the second 

 weight inside, when this difficulty arose. The problem now 

 was, how to get the wire to work freely through the ice, and it 

 was solved in a very simple manner. Someone — I think it was 

 Wilson— conceived the brilliant idea of surrounding the wire 

 with paraffin, which does not freeze, and our excellent engi- 

 neers had soon turned out a small copper tube more than eight 

 feet in length. The new tide-gauge was quickly completed ; 

 the wire was now brought up through a small wooden plug at 

 the bottom of the tube, then through the tube and up over a 

 freely working pulley which hung from the forecastle, through 

 another pulley on the deck, and down to the inside weight, 

 which hung opposite a well-marked scale. When the copper 

 tube, filled with paraffin, was firmly frozen in the ice, we had 

 the satisfaction of seeing the wire working through it practically 

 without friction, and this it continued to do throughout the 

 winter and spring. In searching for possible causes of error, 

 we had, of course, to assure ourselves that the ship rose and 

 fell regularly with the surface of the water, and to make allow- 

 ance for any alteration in trim which might take place from 

 time to time ; but, with all its advantages and disadvantages, 

 the arrangement must be considered about as satisfactory a one 

 as could well be arrived at in the circumstances. 



I have given some account of the erection of our magnetic 

 huts. It would perhaps be as well to give here an idea of the 

 purpose for which they were used. They and all that apper- 

 tained to them were Mr. Bernacchi's special business, and 

 many times a day this officer could be seen journeying to and 

 fro in attendance on his precious charge. Within the larger 

 of the huts, mounted on a solidly bedded oak plank, could be 



