664! TIDES AND CURRENTS. 



The floe ice was always in motion in the direction of the 

 currents and the wind. The ice in Robeson Strait was divided 

 by lanes of open water, which were loo broad to admit of travel- 

 ling on sledges, but too narrow to admit of navigation. 



10. Currents on the East Coast of Greenland (Koldewey). 



The observations on currents show that between the latitudes 

 of 70° N. and 75° N., there are two currents towards the south. 



Outside the ice and in the drift ice quite up to the ice fields 

 which form its inner barrier there is a current of 8 to 10 knots a 

 day, which shifts eastwards or westwards according to the wind 

 and the ice-drift. Close to the coast there is a current of about 

 4 • 6 knots in 24 hours, which almost ceases in summer when the 

 southerly winds are stronger and the northerly winds weaken. 



There is no true current attending the ebb and flow of the- 

 tide, although the height of the spring tide was about 5 feet : even 

 in the neighbourhood of tlie Kaiser-Franz-Joseph Fiord there 

 was no current. 



11. Observations of Tides by Capt. Koldewey at Sabine 

 Island, on the East Coast of Greenland, during the Winter 

 of 1869-70. " Die zweite deutsche Nordpolarfahrt," vol. ii., 

 part 4, 1874. 



Apparatus. 



At the end of one of the davits was fastened (in a vertical posi- 

 tion) a wooden scale, divided into feet and tenths. Vertically 

 below it, a stone sunk in the ground, and fastened by an iron bar, 

 was attached to a light rope, which passed over a pulley on the 

 davit, and had a counterpoise at the other end. 



Attached to the rope was an index, which marked the position 

 of some point of the scale. 



As the ship and scale sank and rose with the ice during the 

 ebb and flow of the tide, the position of the fixed index on the 

 scale showed how much the scale had fallen or risen, and in this 

 way the height and times of high and low water were recorded. 



Capt. Koldewey's method of registering is better than that 

 employed by Dr. Kane, viz , graduating the arc of the pulley, for 

 he found that often the pulley was frozen on its axis, in which 

 case the rope slid over it. 



Dr. Kane tried to correct this defect by taking soundings, but 

 these soundings are somewhat uncertain, because the vessel moves 

 with the ice, and very numerous soundings at various times would 

 be required. 



The difiiculties as to shifting of position are well shown by 

 a note in Dr. Kane's log, of Feb. 3, 1854. He says : — 



" The enormous elevation of the land ice by the tides has 

 raised a barrier of broken tables 72 feet wide and 20 feet high 



