June 25, I860.] ADDITIONAL NOTICES. 235 



obtained by an inspection of the charts published by Dove, showing the 

 isothermal lines of the temperature over that portion of the ocean which lies 

 between Greenland and Northern Europe. From these lines it appears that, 

 in the winter, heat is borne farther north in this locality than in any other 

 part of the Arctic regions. The longitudes distinguished for superior winter 

 warmth extend from the meridian of Greenwich to 60° e. of it. Within this 

 range the line of average temperature of 32'^ in the month of January ad- 

 vances from the latitude of 68° to that of 70°, which it reaches in the fifth 

 degree of east longitude from Greenwich. At the same time the low isothermal 

 line of 5° of temperature is found, in the latitude of 78°, extending from the 

 meridian of Greenwich to the longitude of 40° e., the two temperatures reach- 

 ing higher latitudes within the meridians named than on any others. These 

 are winter temperatures which will be admitted to be extraordinary, and they 

 evidently must be produced by some powerful cause. 



In July the isothermal of 36° of temperature is in about 67° of latitude in 

 the northern part of Am.erica, and, proceeding eastward, it rises to 82° of 

 latitude near Spitzbergen, and then sinks to 69° of latitude over the land in 

 the north of Europe, giving a march of the same degree of temperature in this 

 part of the world through 15° of latitude. The isothermals, in the other 

 jX)rtions of the year, have the same general character as in the two seasoiis of 

 winter and summer, being intermediate between the extremes ; the greatest 

 range of temperature being in the winter, and the least in the summer. This 

 indicates that the local warming influence is the most powerful in winter, 

 when the sun is absent, and that, as direct solar heat increases, the local is 

 partially concealed by the generS,! influence. But the local cause of the rise 

 of the isothermals to more northern latitudes, whatever that cause may be, 

 retains much power in the summer, as is shown by the ascent of those lines 

 at that season. Both the local and the general warming influence tend, 

 therefore, to convert the ice of the Arctic Ocean into water in this particular 

 locality. 



The dynamic force of the Mexican Gulf-stream is sometimes said to be the 

 cause of the high winter temperature of this part. If that opinion were well 

 founded we might reasonably expect that the ocean- stream from the Atlantic 

 would have influence in summer as well as in winter, as the warm water would 

 be more likely to retain its heat in the former than in the latter season. But 

 if, as has been shown, there is good reason to believe that the high tempera- 

 ture of this part is attributable to condensation of atmospheric vapour, which is 

 brought from more southern parts by wind, we may inquire whether we are 

 not authorised to infer that the same process is cQntinued in the parts nearer 

 to the Pole that are yet unexplored. Captain Parry, in his voyage towards 

 the Pole, proceeded to Spitzbergen, and took his departure from that island in 

 latitude 80° and longitude 21° e., on the 23rd day of June. The following 

 are extracts from his account of his voyage, and they show what kind of 

 weather he found on the meridian along which he proceeded : — " We were 

 a good deal surprised on landing in Mussal Bay, latitude 80°, to find that 

 large streams of water were running down all the hills, and that there were 

 large ponds of it in every direction, a circumstance the less expected by us, since 

 we had never seen it half so abundant in any of our winter stations at this 

 season, not even at Winter Island, which lies in latitude 66J°, or nearly 14° 

 to the southward of this." " Ever since we had got into open water we had 

 scarcely once seen the blue sky ; and for ten hours out of every twelve, we 

 had experienced fog, sleet, or snow" (p. 141), "On the 23rd we set ofl" in 

 our boats, the sea being smooth, taking leave of the Spitzbergen shores. The 

 weather soon after became very thick, with continued snow. The tempera,- 

 ture, while we slept in the day, was usually from 36° to 45°. It came on to 

 rain verv hard on the morning of the 26th. It is a remarkable fact that we 



