660 



TIDES AND CURRENTS. 



6. Record of Dr. Kaxe's Tidal Observations, in Winter 

 Quarters at Van Rensselaer Harbour. " Smithsonian Con- 

 tributions," vol. xiii., p. J, &c. 



An attempt was first made to determine the height of the tides 

 by means of a tide-staff, and afterwards by a pulley-gauge 

 attached to the vessel and rising with it. The graduations were 

 on the arc of the pulley. 



The difficulties arising from the slow movement of the vessel, 

 the softness of the bottom, the alteration in length of rope, and 

 especially the slipping of the rope over the pulley, which often 

 froze to the axis, render the series of tidal observations very 

 defective, and entirely break their continuity. 



The observations Avere continued, with several breaks, from 

 October 1853 to October 1854, and part of these series, from 

 their regularity, may probably be regarded as trustworthy. A 

 comparison of the tides at Port Foulke and Van Rensselaer is 

 given in connexion with the account of Dr. Hayes' Expedition. 



P. 81. The observations show that when the sea is partially 

 open the wind has an effect on the tides ; thus : — 



Aug. 17, 1853. With a heavy gale from the southward, " our 

 " flood rose 2 feet above any previous register, overflowing the 

 " ground ice, and our last ebb or outgoing tide was hardly per- 

 ** ceptible.'* 



When the snow melts in spring, the ice cracks open and water 

 rises through the ice, making large basins at every tide. 



The tide at Van Rensslaer is derived from the Atlantic through 

 Baffin's Bay, as shown by the following table : — 



Lat. 



Long. 



High Water 

 at F. and C. 



Highest 

 Spring Tide. 



Julianshaah 

 Frederickshaab 

 Holsteinborg Harbour 

 Whalefish Islands - 

 Godhavn (Disco) - 

 Upernavik 



Wolstenbolme Sound 

 Port Foulke 



Van Kensselaer Harbour 

 Polaris Bay 



o / 



o / 



60 35 



46 5 



62 



50 5 



66 56 



53 42 



68 59 



53 13 



69 12 



53 28 



72 47 



56 03 



76 33 



68 56 



78 18 



73 



78 37 



70 53 



81 38 



61 44 



h. m. 



5 6 



6 3 

 6 30 



8 15 



9 

 11 

 11 8 

 11 24 



11 62 



12 13 



feet. 

 7 

 12^ 

 10 



n 



'3 



8 



7to7i 



9-9 , 



10-8 



8 



The value 12h. 3m. is given by Dr. Bessels as the establishment 

 of Polaris Bay. At other places in W. Greenland an addition of 

 10m. to the mean establishment gives the luni-tidal interval, or the 

 time of high water at full and change. This addition gives 

 12Ji. 13m. for the luni-tidal interval. 



It is estimated that the whole distance, 770 knots, from Hol- 

 steinborg to Van Rensselaer is travelled by the tide in 6J hours, 

 which would correspond to a mean depth of 220 fathoms. 



