| Jan. | Feb. | March. | April. | May. | June. | July. | Aug. | Sept. | Oct. | Nov. | Dec. | Autmn & Wint. | Spring & Sum. | Year. | |
| 1841 | 3.72 | 5.13 | 8.43 | 11.49 | 11.47 | 11.49 | 10.07 | 9.86 | 8.78 | 6.82 | 3.71 | 2.89 | 5.12 | 10.53 | 7.82 |
| 1842 | 3.65 | 4.74 | 8.34 | 10.33 | 9.31 | 9.78 | 8.38 | 9.03 | 7.72 | 7.05 | 3.86 | 2.81 | 5.07 | 9.09 | 7.03 |
| 1843 | 3.82 | 4.08 | 6.87 | 9.71 | 9.24 | 10.14 | 9.57 | 10.08 | 8.81 | 6.82 | 3.82 | 2.79 | 4.70 | 9.59 | 7.15 |
| 1844 | 2.81 | 3.43 | 6.95 | 9.53 | 8.42 | 8.88 | 8.38 | 9.28 | 8.23 | 6.54 | 3.94 | 2.98 | 4.44 | 8.79 | 6.61 |
| 1845 | 2.20 | 4.69 | 8.26 | 11.93 | 10.88 | 10.73 | 9.44 | 10.42 | 8.82 | 7.34 | 4.49 | 8.34 | 5.89 | 10.87 | 8.13 |
| 1846 | 3.30 | 6.94 | 9.53 | 12.27 | 12.58 | 11.21 | 11.37 | 11.49 | 10.39 | 7.82 | 5.66 | 3.22 | 6.08 | 11.25 | 8.81 |
| 1847 | 3.30 | 6.35 | 9.85 | 12.43 | 11.81 | 11.76 | 10.94 | 12.87 | 12.06 | 11.53 | 7.06 | 4.70 | 7.63 | 11.98 | 9.55 |
| 1848 | 6.52 | 9.01 | 11.96 | 14.56 | 14.22 | 13.80 | 14.67 | 15.40 | 14.00 | 10.30 | 5.78 | 3.53 | 7.85 | 4.44 | 11.05 |
| 1849 | 7.27 | 8.42 | 14.08 | 16.86 | 13.67 | 13.86 | 12.57 | 11.54 | 10.79 | 9.12 | 5.41 | 4.09 | 8.06 | 13.21 | 10.64 |
| 1850 | 5.98 | 8.84 | 12.15 | 14.32 | 14.05 | 13.39 | 12.53 | 12.68 | 12.64 | 9.04 | 6.20 | 3.45 | 7.61 | 13.27 | 10.44 |
The Philadelphia and Toronto observations disclose the same state of facts.
Dr. Lamont, also, in his article, gives us the following table of the magnitude of the variations derived from observations at Gottingen:
| 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 and collected over our heads. We set it in motion, and obtain it by heating different metals in connection, or the same metal unequally; and from certain animals—like the torpedo and the gymnotus—whose organization is such as to enable them to evolve it. In all these cases, and they constitute an epitome of the principal methods by which we obtain it in a distinct form, it is made to flow in currents. When thus obtained, and imprisoned in non-conductors, it may be discharged, and with somewhat different effect, as it is discharged in a mass, disruptively, as it is called, as from the clouds in lightning, or permitted to flow convectively, in currents, along the wires of a galvanic apparatus, or in heated air, as from the earth to a cloud in the tornado.
It is, moreover, capable of division into positive and negative, and when concentrated or disturbed in one body, it tends to create a similar disturbance or division in a contiguous mass. To this action of electricity, the term static induction is applied. Thus, a positively electrified body induces a division of the electricity in a contiguous body, if both are insulated or surrounded by a non-conducting medium; the negative electricity of the contiguous body being attracted by, and tending to pass to, the positive of the adjoining body, and the positive being repelled to the opposite side. That, in its turn, if sufficiently powerful, tends to disturb the electricity of its neighbor, and attract away its negative electricity; or, if the body which contains it is free to move, to attract that. Thus, by the conflicting action of a positive atmosphere, and a negative earth, and perhaps counter-trade, influenced by magnetism and the solar rays, the currents and winds of the atmosphere are produced, the atmosphere moving with exceeding ease and rapidity. Electricity, excited into currents, or obtained and discharged in either of the methods enumerated, is identical in character, and produces certain well-known effects:
1st. Physiological.—Shocking and convulsing the animal system; producing a peculiar sensation on the tongue, and a flash before the eyes, and in sufficient quantity destroying life.
2d. Magnetic.—Deflecting the needle, and, by a suitable arrangement of wire into helices, conferring magnetic power, or constituting magnets.