ES, IN ACCORDANCE WITH THE ALTERNATIONS OF THE WEATHER. If heeded,
they would save thousands, every year, from premature death.

[Illustration: Fig. 18.]

The effect of this difference of magnetic intensity upon the climate of
Europe is marked. There, the excessive summer heat, which our greater
magnetic intensity and larger volume of counter trade give us, is unknown.
Hence, while we can grow Indian corn (which requires the excessive summer
heat) over all the Eastern States, up to 45 deg., and in some localities east
of the lakes to 47 deg. 30', and to 50 deg. west of them, to the base of the Rocky
Mountains, and notwithstanding the increase of elevation, they can not
grow it except over a limited area, and with limited success. Nor can
they, or the inhabitants of any other country except China, grow
profitably the kind of cotton which is so successfully grown in the
Southern States of the Union. Nor can China do so to a considerable
extent, because of the mountainous character of the surface. To a level
and remarkably watered country, greater magnetic and electric intensity,
and a greater volume of counter-trade, we are, and ever shall remain,
indebted, for an almost exclusive monopoly in the growth of two of the
most important staple productions of the earth. On the other hand,
although the same magnetic intensity, and its winter excess of positive
electricity and cold, make our winters extreme, there are but few of the
productions of temperate latitudes which we can not grow successfully, and
they are comparatively unimportant.

A Fort Vancouver, Oregon Territory
B Fort Brady, outlet of Lake Sup.
C Hancock Barracks, Houlton, Me.
D Fort Armstrong, Rock Island, Ill.
E West Point, New York
F Washington, D. C.
G Jefferson Barracks, near St. Louis
H Fort King, interior of East Florid.
I Environs of London
K Rome, Italy

A B C D E F H I J K

Lat. 45 deg. 46 deg. 46 deg. 41 deg. 41 deg. 38 deg. 38 deg. 29 deg. 51 deg. 41 deg.
37' 39' 10' 28' 22' 53' 28' 12' 31' 54'
Annual
Range. 78 110 118 106 91 84 89 78 67 62

Jan. Min. 17 -21 -24 -10 -1 14 10 33 16 29
Max. 58 40 41 48 53 57 60 83 49 58
Feb. Min. 32 -22 -11 -6 2 16 11 43 19 33
Max. 55 44 42 56 56 62 70 84 54 60
M