Jan., 1889. 
TOUR IN NORWAY. 
3 
During this inland trip, and at the various stopping places of 
the North Cape steamer, we had opportunities for collecting 
plants : we were much struck with the active condition 
of the vegetation,especially in the leaves of the trees; and the 
country was quite a wild garden of flowers, many British 
plants being met with in unusual luxuriance of growth. This 
is due partly to the mild climate caused by the Gulf Stream, 
which impinges on the whole coast up to the North Cape. 
The temperature on the North Cape at midnight was as high 
as 55°, although it is within 19°, or only 1300 miles, distance 
from the North Pole ; and at Hammerfest, which is the most 
northern town in the world, the temperature was actually 70° 
in the shade at midday. 
The effect of the Gulf Stream is shown upon the circum¬ 
polar map in Plate I.,, in which is given the temperature curve 
of 82° ; or the curve passing through all the localities in which 
the mean annual temperature is the freezing point, the winter 
averaging as much below the freezing point as the summer 
averages above it. This curve reaches nearly as low a latitude 
as 50° in the two great continents of Asia and America, being 
there at about the latitude of the South of England ; but the 
gigantic warming effect of the Gulf Stream indents the curve 
past England and the coast of Norway, to a point actually 
600 miles north of the Arctic Circle, although the curve is 
1000 miles south of the Arctic Circle in the continents of 
Asia and America. This causes the remarkable and exceptional 
mildness of climate of the whole coast of Norway up to the 
North Cape, as well as of the west coast of the British Isles. 
The great exciting cause however of the active condition 
of the vegetation, is the continuous sunlight that is day and 
night acting upon the plants: their development is never 
checked by the darkness of night, and there is the continuous 
stimulus of sunlight all through the summer. At the North 
Cape itself, the sun never sets for 2J months, from lltli May to 
30th July, and in the other less northerly positions within the 
Arctic Circle the sun is so little below the horizon for any 
portion of that time, that there is practically continuous day¬ 
light throughout the 2J months. 
In our trip we had the sun continuously above the horizon 
for six days and five nights, and were so fortunate as to see 
the Midnight Sun on four successive nights. At the North 
Cape at midnight the sun was about eight diameters above the 
horizon, when we were there on July 6th, and it was shining 
brilliantly, with a light about equal to the light that we have 
usually on autumn afternoons in this country. Measured 
actinically, the light at midnight was found to be equal to 
