4 



" As it was considered possible that the ice, owing to the proximity of the land, might not maintain a 

 uniform position relative to the surface of the water, a small hole was occasionally opened close to one of 

 the tripod legs, to which was attached a mark, indicating the height to which the water should rise. A 

 few observations showed that no error from this cause was to be apprehended. 



" This gauge was placed about 200 yards from the ship, and two-hourly readings with but slight 

 interruption were continued from April 12 to April 28. 



"Some sluggishness in its movement, which was eventually noticed, and its final breakdown, was 

 possibly partly due to the thickening of the ice, but principally, I think, to the fact that too small a block 

 was employed at the tripod head. The scale was, by accident, secured so that the readings increased 

 upwards, consequently they have to be inverted.* 



" It was originally intended to place a tide gauge in the ship, owing to the far greater convenience of 

 position, but it was thought that the position of the ship relatively to the water surface might alter and 

 this might lead to errors. It was hoped that by placing one on the ice as well as one in the ship, check 

 observations might be obtained to determine if this source of error existed. This was eventually 

 accomplished on April 25, but by the time the ship gauge was erected the outside gauge had ceased to be 

 entirely satisfactory, for the reasons given. The observations, however, show a close approximation of 

 movement. 



Maximum 



& 



7 minimum 

 arrangement 



on 

 scale 



bide rising 



Fig. 2. 



" The ship gauge was arranged as shown in fig. 2. The supporting blocks were secured rigidly, and, 

 until May 10, the wire was led directly through the ice. As the friction was gradually increasing, a 

 suggestion made by Dr. WILSON was adopted on that date, and the wire was taken through a tube, filled 

 with paraffin oil and closed at the top and bottom with a hard wooden plug through which the wire 

 passed. A maximum and minimum arrangement, with balanced weights, was added, as shown in the 



* This oversight was rectified before May 12. G. H. D. 



