CONCLUDING REMARKS. 207 



the floes of ice. In case of frost, the screw is 

 wholly under water, and entirely free from that 

 accumulation of ice, which would take place 

 about the paddle floats and boxes of an ordinary 

 steam-vessel, to the great detriment, if not the 

 entire destruction of the wheel. Should the ves- 

 sel be caught and compelled to winter, a steam- 

 apparatus for warming the vessel throughout 

 could be fitted with little trouble. And as the 

 propeller is only intended to be used as an 

 auxiliary power, a small high-pressure engine 

 would be all that would be required, and conse- 

 quently it would take up but little of the stowage 

 of the vessel. In short, it seems as if this 

 invention had appeared about this time to stimu- 

 late us to further exertion, and the auspicious 

 return of Captain James Ross from the Antarctic 

 seas, with officers and seamen already accustomed 

 to the ice, and with two vessels ready strength- 

 ened, to which the propellers could be applied at 

 a moderate expense, appears to mark the present 

 as a period at which arctic research might be 

 most advantageously resumed. 



In connexion with this attempt, that most 

 interesting and important question, of the com- 

 pression of the earth at the Poles, might undergo 

 an investigation, by a direct measurement of an 

 extensive arc of the meridian at Spitzbergen. 



