I9 J 5- No. 2. SPITSBERGEN WATERS. 43 



drifting, and the direction of the drift was indicated by the direction of 

 the vertical plane of the sloping sounding-line. Theoretically this method 

 should give fairly accurate results., but practically this is hardly the case. 

 Owing to its weight, the sounding-line will form a curve, and the greater 

 its angle with the vertical, the greater does the curve become. It will 

 consequently be necessary to pay out more line than would have been 

 the case if the line could have been kept straight; and it is hardly pos- 

 sible to calculate how much. Owing to this circumstance the method will 

 therefore give too great values for the drift of the ship. On the other 

 hand there is naturally a risk that the lead may be dragged along the 

 bottom, and if so this will naturally tend to make the mearurements of the 

 drift too small. Another drawback with this method is the difficulty of 

 measuring the direction of drift with sufficient accuracy, and it is especially 

 difficult to measure the changes in the direction of the drift during the 

 time of the observations, because the direction (/'. e. the azimuth) indicated 

 by the line will change much more slowely than the direction of the drift, 

 especially if the line forms a great angle with the vertical, and there is a 

 great distance between the ship and the lead on the bottom. If the line 

 is kept tight it will point the whole time towards the lead, and even though 

 the direction of the drift may change a great deal, it can cause only a 

 very slow alteration in the direction of the line. The currents at inter- 

 mediate depths may also have appreciable effect upon the direction of the 

 sloping line. This kind of observation is not therefore of much value for 

 computing the actual current at higher levels from observations made simul- 

 taneously with a current-meter from the drifting ship. 



The method might, however, have been useful for controlling the 

 observations of the drift of the ship made by a current-meter lowered to 

 the water-strata near the bottom. But unfortunately this was not done 

 regularly, as we had too few winches with sounding-line, and too few men 

 for the observations. After having made several attempts with the above 

 method at Stations 19 and 20, on August 4th and 5th, and after having 

 found by computation that it did not give satisfactory results, I gave up this 

 method, and decided instead to work with two current-meters, one lowered 

 to a water-stratum near the bottom, and the other used simultaneously at 

 higher levels. Some few observations were, however, made simultaneously 

 with the two methods. 



On August 5th, from 4.11 to 4.21 p. m. an observation vas made with 

 a current-meter at 540 metres. The depth of the sea was then 575 metres. 

 The observation gave no movement, and at that time and daring the pre- 

 vious hour the observations also gave no movements at higher levels. It 



