cHAP, vitt.] THE GULF-STREAM. 393 
Scottish Meteorological Society, Mr. Buchan, with 
regard to the temperature of the sea on the coasts 
of Scotland. 
5. From the publications of the Norwegian Insti- 
tute on sea-temperatures between Norway, Scotland, 
and Iceland. 
6. From the data furnished by the Danish Rear- 
Admiral Irminger on sea-temperature between Den- 
mark and the Danish settlements in Greenland. 
7. From the observations made by Earl Dufferin 
on board his yacht ‘Foam’ between Scotland, Ice- 
land, Spitzbergen, and Norway. 
And finally, from the recent observations collected 
by the English, Swedish, German, and Russian ex- 
peditions to the arctic regions and towards the 
North Pole. 
Dr. Petermann has devoted the special attention 
of a great part of his life to the distribution of heat 
on the surface of the ocean, and the accuracy and con- 
scientiousness of his work in every detail are beyond 
the shadow of a doubt. Plate VII. is in the main 
copied from his charts, with a few modifications and 
additions derived from additional data. The remark- 
able diversion of the isothermal lines from their 
normal course is undoubtedly caused by surface ocean- 
currents conveying warm tropical water towards the 
polar regions. This is no matter of speculation, for 
the current is in many places perceptible through 
its effect on navigation, and the path of the warm 
water may be traced by dipping the thermometer 
into it and noting its temperature. 
In the North Atlantic every curve of equal tem- 
perature, whether for the summer, for the winter, for 
