342 



Mr. J. Y. Buchanan. 



[Feb. 2, 



mark-buoy was anchored in 175 fathoms, just outside the precipitous 

 edge of the bank. 



On the afternoon of the 21st October, 1883, I spent several hours 

 in one of the ship's boats made fast to this buoy, and during that 

 time I made frequent observations of the rate and direction of the 

 surface current as well as of the general direction of the under 

 current. (See Table I.) 



It had been observed during the previous day and night that at 

 times the current set strongly to the southward, at other times 

 became nearly slack and even ran to the northward. While the 

 boat was being lowered and got away the ship drifted very slowly to 

 the northward past the buoy and against a light northerly air blowing 

 at the time. When the boat was made fast to the buoy the current 

 was found setting to the northward, against the wind and sea, and 

 measures were immediately taken for determining its direction and 

 velocity at frequent intervals. For this purpose an ordinary life-buoy 

 was attached to the end of a line which was marked at every fifth 

 fathom with a piece of wood, which also served the purpose of keep- 

 ing the line afloat and of showing whether it was going out straight 

 or not. Although the wind was only barely perceptible, it was found 

 to retard the life-buoy. An arrangement of canvas was accordingly 

 weighted and hung down in the axis of the buoy. This greatly in- 

 creased its hold on the water and made its movements dependent 

 only on the current. The direction of the current was observed with 

 a pocket azimuth compass for use on land. Although there was 

 hardly any wind, there was a considerable swell coming up from the 

 north, but it did not produce any motion sufficiently violent to in- 

 terfere with the use of the compass. In order, however, to remove 

 any uncertainty, which might have existed with regard to the 

 correctness of the bearings so observed, I always took a bearing of 

 the sun at the same time, as an index of the trustworthiness of the 

 current observations. 



No accurate measurements were made of the under current, but 

 while the surface current was being observed a tow-net lashed to a 

 sounding line was lowered to 35 fathoms for one hour, and to 

 70 fathoms also for an hour. The directon taken by the sounding 

 line showed that down to 75 fathoms the direction inclined slightly 

 more to the eastward than the surface current, and its strength seemed 

 to be slightly greater. 



The observed bearings of the sun give for the local variation 17° W., 

 17° W., 21° W., 21° W. According to the chart the variation is 

 19° W. The bearings therefore as determined in the boat may be 

 depended on to a quarter of a point. 



Time was taken by a watch set to local time. In letting the 

 current log run out care was taken to put no strain on the line, so 



