discovered, and came to the following conclusion respecting the origin and distinct character of tornadoes and storms:
Origin of Storms and Tornadoes.—"I had found the existence of two opposing currents of air of different temperature, coming respectively from northwest and southwest, acting suddenly against each other after a sultry calm of some duration; and shortly, a third gyratory force making its appearance between them, traveling in their diagonal, growing to such magnitude as to obliterate all trace of the straight-line forces of the opposing currents, and finally abruptly disappearing. The two currents must have been, during the period of sultry calm, in a state of equilibrium, since the clouds were observed to remain for some time almost stationary. South of the tornado's track the southwest wind prevailed until the beginning of the tornado, and, from information obtained for me by ex-President Hill, it appeared that a storm had traveled from northwest to southeast over the States of New Hampshire and Vermont, and that during its progress a southwest wind was replaced by a northwest wind. I was thus led to conclude that the storm announced that afternoon by the black bank of cloud consisted in the conflict of two aërial currents of different temperature—that the colder northern current displaced the warmer southern current in the direction from northwest to southeast, gradually decreasing in velocity until, north of Waltham, West Cambridge, and Medford, it came to a perfect standstill, producing the sultry calm felt before the tornado.
"Here the two currents, being in equilibrio, exerted a great compressive force against each other. The equilibrium was disturbed by the uneven configuration of the earth around Prospect Hill. This disturbance produced the tornado, which traveled, not in the direction of the storm toward the southeast, but in the diagonal of the two opposing currents over their region of calm at their line or meeting, and in and underneath the black bank of clouds stretched out from west to east which must have marked this line of meeting.
"I came thus to two distinct phenomena—the tornado, and the storm in the ordinary sense of the word—both different in their origin, nature, direction, progress, and appearance, and governed by entirely different laws."
Continuing his observations for several years, he came to the conclusion—
"That storms in the temperate zone at least, and over the United States, are the effect of the conflict of opposing aërial currents of different temperatures, and not the cause of these currents and temperatures, as seems to be assumed by some cyclonists."
Continuing and extending his observations and studies in the general held of meteorology, our author compares his own method of procedure with that usually pursued by others, as follows:
"Having found, during my investigations, that tornadoes and other storms are different phenomena, and that they follow different laws, I endeavored to investigate storms in general by the same method I had used with the tornado.
"My researches were not made by filling out the ordinary meteorological formulas from observations made three or four times daily, as is the custom. I had learned that no storm will be accommodating enough to develop itself just at the specified periods for observing; I do not believe that this method will ever lead to any definite results.
