94 REPORT—1848. 
European curves, with the exceptionof the Scandinavian curves, which main- 
tain their deviating form. It is only in the Kirghis steppe that the depression 
of temperature still continues to be remarkable, and does not disappear until 
April. The American curves become flatter in the interior of the continent, 
but as they preserve their steepness on the eastern coast, their concavity 
moves gradually towards Newfoundland. The Atlantic ocean shows the pe- 
culiarity that the curves on this side of the tropic of Cancer have their con- 
vex summits in the same meridian (that of the Cape de Verd Islands) in 
which the inter-tropical curves have their concave summits. This isexplained 
by the Gulf-stream turning to the south at the bank of Flores. On the 
western coasts of North and South America the form of the curves remains 
the same, the convex summits are everywhere close to the coast. In the 
Ethiopian Sea the curves are flatter, and are very close together near the Cape 
of Good Hope and on the south coast of Australia, because the line of 
0° Reaumur, or 32° Fahrenheit, has its convex summit in these meridians 
in 57° lat., and the increase of temperature from thence, which is at first. 
slow, becomes extremely rapid from 45° S. lat. 
In April two spaces of unusually high temperature, bounded by isothermals 
of 24° Reaumur, or 86° Fahrenheit, are developed in the middle of Northern 
Africa and in the interior of Western India. Everywhere in Asia and 
middle Europe, the isothermals are almost parallel with the parallels of 
latitude. It is only the curves of 4°, 0° and—4° Reaumur, 41°, 32° and 23° 
Fahrenheit, which preserve their extraordinary bend. The line of —4° Reau- 
mur, or 23° Fahrenheit, passes from the southern part of Hudson’s Bay 
along the west coast of Greenland up to Spitzbergen, and sinks from thence 
down to the entrance of the White Sea. The line of 0° Reaumur, or 82° 
Fahrenheit, runs from Cape Breton to the south point of Greenland, through 
Iceland, almost up to Bear Island; thence to the North Cape, and sinks on 
the crest of the Scandinavian Alps down to the latitude of Drontheim, from 
whence it bends eastward. The ice drifting down from the coast of Green- 
land and Baffin’s Bay is the cause of this phenomenon. 
In May this effect of the drift-ice is still more decided ; from Nova Scotia 
to Newfoundland the isothermals are crowded most closely together : hence 
arises in the spring of Newfoundland the remarkable phenomenon of the silver 
dew, when warm south winds cover the trees with a thick crust of ice, convert- 
ing, as Bonnycastle tells us, every tree into a candelabra of the purest ery- 
stal ; hence too the thick fogs which at this season obscure the entrance to 
Baffin’s Bay. Meanwhile the hot space in Africa, bounded by an isother- 
mal of 24° Reaumur, or 86° Fahrenheit, has extended and united itself with 
the hot space in Western India. On the northern side of this space the 
temperature decreases rapidly up to the shores of the Mediterranean: the 
S.E. trade in the form of a S.W. monsoon, advances towards the hot space. 
The curves in Northern Asia, which in the interior continue parallel to the 
circles of latitude, on approaching the east coast of the old continent, rise 
rapidly, and then sink down again with equal rapidity in Kamschatka, towards 
the Aleutian and Kurile Islands. 
In June the relations are analogous; the hot African space reacts in 
Europe up to Christiania; for the European isothermals still rise near the 
west coasts, and do not begin their easterly course until the meridian of Berlin. 
The Fox Channel, the Karian Gate, and Behring’s Straits, as outlets of the 
Icy Sea, show their influence in producing concave inflections in the generally 
regular course of the isothermal lines at this season, In America, the lowest 
parts of the lines are close to the east coast ; the warm space, enclosed by a 
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