CONTINUED VOYAGE OF THE TWO SHIPS. 51 



were in that part of the somewhat changing boundary 

 where the warm (so called) Grulf Stream coming up from 

 the south and the cold Arctic current coming down from 

 the north just meet. This Gulf Stream is known not only 

 by its relative warmth, but by the greater saltness and 

 deep blue colour of its waters. The beautiful blueness 

 of the sea struck us as soon as we left the North Sea. 

 But from this time until we reached the ice the colours 

 changed continually, and sometimes very quickly, from 

 dirty blue, light blue, greenish blue, bluish green, clear 

 and transparent green, greyish green, and so on, so that 

 our attempts at representing a series of these colours 

 became a failure.* Sharp limits between green and blue 

 water, such as have been often observed, not only in the 

 Atlantic but also in the Arctic Ocean, we never met 

 with.* As regards temperature, the blue water certainly 

 was the warmest; but even here sudden and considerable 

 differences were almost imperceptible. 



With our advance towards the north-west the warmth 

 of the water gradually decreased. Exactly corresponding 

 to the isotherm for May, which we found in 1868, we 

 registered on the 6th of July at noon 42.12° Fahr., and 

 the next day, at the same time, it was already two 

 degrees lower. On the other hand we first found the 

 temperature at zero, or below zero, in the neighbourhood 

 of the ice, whilst in May, 1868, it was as low as that at 



* A glance at the surface is not sufficient to decide the i-eal colour of 

 the water, as it is aifeeted by the reflected colour of the heavens. The 

 influence of the latter must therefore be excluded ; and we therefore 

 examined the water througli a tube. A convenient arrangement for the 

 purpose oflfered itself in the oj)ening for hauling in the screw. 



* It is said that ships are sometimes half in blue and half in green 

 water. 



E 2 



