| Year.|Mean of Year.|
|--------------------|
| 1835 | 9.57 |
| 1836 | 12.34 |
| 1837 | 12.27 |
| 1838 | 12.79 |
| 1839 | 11.03 |
| 1840 | 9.91 |
| 1841 | 8.70 |
+--------------------+

A comparison of these tables, and particularly the latter, with Schwabe's
table of spots, is interesting. There is obviously a greater mean
variation when the spots are most numerous. Comparing the two with the
tables of Hildreth, in relation to the temperature, from 1830 to 1840,
there is, to say the least, a most remarkable coincidence. And there are
others equally remarkable.

There are also irregularities of action disclosed by all, in different
months of the different years, and of the same year, which are obviously
connected with the difference of the seasons; and there are constantly
occurring irregularities and disturbances which correspond with the, as
constantly occurring, irregular atmospheric phenomena. A wide field is
here opened for investigation and research. I have not time or opportunity
to pursue it. Enough appears, so far as I have examined, to confirm the
belief that magnetism is actively concerned in the production of the
varied changes, as well as the normal conditions of the weather.

In what manner does it act? An answer to this requires an extension of the
inquiry. The lines of magnetic force are every instant passing upward from
the earth, _around_ and _through_ us. Their connection with heat is
unquestionable. They are intimately associated, also, with another equally
obvious and intensely active agent--electricity. We speak of this as an
independent, imponderable, elementary body, but how little we yet know of
it. It is every where, in every thing, easily excited into action, and
then traceable to a certain, but limited extent. It is set in motion, and
becomes obvious to us, by the chemical action of the acids and metals of
a galvanic apparatus. We separate it from the atmosphere by friction and
excitation, upon non-conductors, as in the electric machine; by the
cleavage of crystals and other exciting operations. We obtain it from
magnets, by the magneto-electric machine, and from the lines of magnetic
force which are ever passing into the atmosphere from the earth, by
intersecting them with a movable iron wire, properly insulated. _From the
current of magnetism which has passed through us from the earth,
electricity may thus be separated an