PROCEEDINGS OP THE POLYTECHNIC ASSOCIATION. S91 



through which the waters of the Polar sea mingle with the waters 

 of the Atlantic and Pacific oceans, — these breaks being Baffin's bay. 

 Behring's strait, and the broader opening between Greenland and 

 Nova-Zembla. The Avaters of the Pole are constantly displaced by 

 the waters of the equator, so that the great body of the former is 

 never chilled to within several degrees of the freezing point. 

 Hence the whole region is tempered with a warmth above that 

 which is otherwise natural to it. The surface v.'ater only reaches 

 so low a temperature as to freeze. ' When the wind moves the 

 sm-face water the particles Avhich have become chilled by contact 

 with the air mingle in the rolling waves with the warm waters 

 beneath, so that ice can only form in sheltered places, or where 

 the water is so shallow that it becomes chilled to tlic bottom, or 

 where the air over the sea is uniformly calm. As the winds blow 

 as fiercely over the Polar sea as in any other quarter of the Avorld, 

 the Polar ice covers but a small i^art of the Polar water, being 

 found onlyAvhere it is nursed and protected by the land. It clings 

 to the coasts of Liberia, hugs the American shore, fills the narroAV 

 channels which drain the Polar Avaters into Baffin's bay, crosses 

 thence to Greenland, from Greenland to Spitzbcrgcn, and from 

 Spitzbergcn to Nova-Zembla, investing the Pole Avith an uninter- 

 rupted belt of ice clinging to the land, more or less broken as Avell 

 in Avinter as in summer, but Avith its fragments ever moving to and 

 fro, forming a barrier Avhich has thus far been impenetrable to the 

 arts and energies of man." 



Dr. R. then gave his OAvn views as folloAvs : 



The Avater floAving into the Polar sea through Behring's strait 

 is 20° F. Avarmer at fifty fathoms deep than on the surface (see 

 Com. Rogers' N. W. expedition), it being Salter than the surface. 

 No glacier can, according to Dr. Hayes' theory, be pushed into 

 this Avater, as but tAventy feet in thickness is added yearly to this 

 ice belt, and as it takes 100 years to form 2,000 feet in thickness, 

 consequently, the berg, if pushed into the sea by glaciers llov/ing 

 on the bottom until their bulk Avas overcome by the gravity of the 

 water, the}'- Avould melt as fast as they reached the Avater. The 

 line of perpetual ice is hit. 80°; the Polar sea is 2,000 miles in 

 diameter — making a coast line of ice for the Polar sea of from six 

 to ten thousand miles. The rivers flowing north never pass this 

 ice belt, but floAV in fresh water channels, between the coast and 

 ice belt, into the Atlantic ocean. The ice bergs arc suspended 

 over the Polar sea till their size and Aveio-ht and the influence of 



