The Philosophy of the Weather. And a Guide to Its Changes

by T. B. Butler

3d. Luminous.—Producing light—by a spark, as it does in natural phenomena—by the glow, the brush discharge, the ball of flame, the flash, or the chain of lightning, and probably the aurora.

4th. Evolving heat.—Melting metallic substances by concentration, with a great intensity of heat—as the wire of the galvanic apparatus, and as is sometimes seen in the effects of lightning in fusing metals on persons stricken; and setting combustibles on fire.

5th. Attraction and repulsion.—Attraction, when the currents flow parallel with each other, or are of opposite natures, and repelling when of like character.

6th. Induction.—Inducing attendant circular or other secondary currents, such as may be seen in the atmosphere during its most violent displays of active energy.

7th. Capable of being dissipated by heated air, or carried off by moisture, although isolated by dry air, of ordinary temperature, which is a bad conductor.

Now, although magnetism can not be collected, imprisoned, or discharged, like electricity, or collected at all, but by its adherence to some substance capable of magnetization, it is obvious there is an intimate association, at least, between it and electricity. They are never found alone. All electricity will magnetize. All magnetism will evolve electricity. All currents of electricity have encircling currents of magnetism, and all deflect the magnetic needle. All magnetic currents give out to intersecting wires, currents of electricity, and all magnets induce them.

Electricity, therefore, whether identical in substance with magnetism, but differing in form, or whether merely associated with it, as is variously believed, should be present with magnetism in greater quantity or intensity where magnetism is most intense, and active, and whenever present, should be active and influential. And so we find, from observation, the fact to be. No inconsiderable effort has been made by the advocates of the caloric and mechanical theories, to ignore the agency of electricity and of magnetism, in the production of the varied meteorological phenomena. But it will not do. The phenomena, grouped and analyzed, disclose a potential-controlling, magneto-electric agency, and meteorology will advance rapidly to perfection, as a simple, intelligible, and practical science, as soon as that agency is admitted.

Electricity is always perceptibly present in storms and showers within the tropics. Most of the rain, from the tropical belt, falls from “thunder showers.” So hurricanes and typhoons, and all tropical storms, are confessedly, and in proportion to their intensity, “highly electric.” This excess of quantity or activity of electricity, exists in connection with the movable atmospheric machinery. When it moves up north in summer, and arrives at its highest point of northern transit, storms are very uncommon, and the tropical forms of cloud and showers, with thunder and lightning, prevail. This is most obvious, if not most influential, where the magnetic intensity is greatest. Violent showers, and gusts, and tornadoes, are more frequent in this country than in Europe; and over the area of greatest intensity, as in Ohio, than at a distance on the extreme eastern or western coast. And the same is true over the intense magnetic area of Asia.

Electricity, too, like magnetism, has its diurnal, and doubtless its annual and decennial variations, and also its irregular ones, and they are most obviously and intimately connected. Magnetism and electricity together, constitute the aurora. Its culmination is in the magnetic meridian—it affects the telegraph wires—is connected with the irregular disturbances which affect the magnetic needle, and does not exist in the limits of the trades, although occasionally seen from thence, when it passes south, and near them.

The aurora sometimes extends south in waves, as do the magneto-electric, atmospheric, periodical changes of cold and heat, and storm, and sunshine. The aurora is connected with the formation of cloud, and with a smoky atmosphere, similar to that with which we are familiar in summer and autumn. Thus Humboldt (Cosmos, vol. i. pp. 191, 192).