Monday, January 23. 2 P. M.-An Introductory Address, by Lemuel Allen, Esq.; Drainage and Irrigation, a lecture by Prof. S. W. Shattuck, of the Industrial University. 7 P. M.—The Political Economy of Agriculture, by Dr. J. M. Gregory, Regent of the University. Tuesday, January 24. 9 A. M.-Dr. E. S. Hull, on Horticulture. 2 P. M.-Dr. E. S. Hull, on Horticulture. 7 P. M.-Dr. Manly Miles, Professor of Agriculture, Michigan Agricultural College, on Principles of Mixed Husbandry. Wednesday, January 25. 9 A. M.-Dr. Miles, on Rotation of Crops. 2 P. M.-Dr. Miles, on Manures. 7 P. M.-Prof. A. P. S. Stuart, of the Industrial University, on Agricultural Chemistry. Thursday, January 26. 9 A. M.—B. S. Prettyman, Esq., on Cultivation and Husbandry of the Cereals. 2 P. M.-Prof. W. M. Baker, of the Industrial University, on Ancient Agriculture. Each lecture, address or talk, will be followed by a discussion of the topics embraced therein. AT COBDEN OR SOUTH PASS-FREE. Under the auspices of the Industrial University, the following lectures or addresses, each to be followed by a discussion on the topics embraced therein, will be held at Cobden, February 6th to 9th, 1871: Monday, February 6. 2 P. M.-Prof. T. J. Burrill, of the University, will lecture on Flowerless Plants, including the Fungi. 7 P. M.—Dr. J. M. Gregory, Regent of the University, will lecture on the Political Economy of Agriculture. Tuesday, February 7. 9 A. M.-Dr. Wm. LeBaron, State Entomologist, on Entomology. 2 P. M.-Dr. E. S. Hull, on Horticulture. 7 P. M.-Dr. E. S. Hull, on Horticulture. Wednesday, February 8. 9 A. M.-Dr. Manly Miles, Professor of Agriculture in the Michigan Agricultural College, will lecture on the Principles of Mixed Husbandry. 2 P. M.-Dr. Miles, on Manures. 7 P. M.-Judge A. M. Brown, of Villa Ridge, one of the Trustees of the University, will give an address. Thursday, February 9. 9 A. M.-Prof. A. P. S Stuart, of the University, will lecture on Agricultural Chemistry. EXPLANATION AND REMARKS ON THE DIAGRAM. I. The Meridianal or diurnal line or belt of maximum heat (A. B.) revolves round the globe every twenty-four hours, with the sun, and over each meridian about three o'clock in the afternoon, at right angles to the equator. The Equatorial, or annual line, or belt or zone, of maximum heat, on the contrary, swings from north to south between the tropics parallel with the equator, advancing and receding with the sun, and the returning seasons of each year. The point, or area, or focus, of greatest heat on the globe is where these two lines intersect, as at OOO, which point of course revolves around the globe every twenty-four hours, and tends to draw all the great surface sircurrents after it, and to deflect all the other currents toward it. The upper return currents of air, including what are called the counter trade winds, move in directly the opposite direction to the surface currents (as indicated by the arrow-heads of the diagram), when not disturbed by local forces. The perpetual intersection of the several parts of this great cross-belt of maximum annual and diurnal heat, with its maximum focus of heat at its center, is the natural and necessary cause of the deflection of the trade-winds toward the west, and the upper return currents toward the east, so generally, however foolishly, attributed to the varying velocities of different parallels of latitude-as any one can see from a moment's reflection. For it is plain that the zone or belt of maximum heat or wind-power on the earth's surface is not a single belt, encircling it from east to west near the equator, as is commonly represented, but a cross of belts, the one running east and west with its annual slides, the other at right angles to it, with its diurnal rotation and focus of maximum heat ever attending it. It may be, to some, an interesting coincidence, that our natural sun, at the maximum of his effulgence and power, exerts his paramount influence on our globe through a form of a cross, and not, as scientists have taught us, through one continuous mathematical line or belt around it. An adroit devotee to analogies, or correspondences, could write a whole ship-load of books on this simple fact, not wholly without interest. II. When the sun is over the equator, and the days and nights are equal, the crepuscular line, as it has been called, or line of daylight, is parallel with the meridianal line of maximum heat, (A. B.); and the point or forces of greatest heat (O) will revolve on the equator. But when the days are longest, and the sun is over the tropic of Cancer, this line of daylight will be E. F.; which line will bound the hottest hemisphere of the globe, toward which all great air currents must tend E. A. C. F.; being deflected toward a line at right angles with the line E. F. This of course strengthens the tendency to our south and southwest winds in summer; for precisely the opposite reason, when in our shortest days in winter, the sun is over the tropic or calms of Capricorn, and this crepuscular line has swung around to C. D., and C. F. B. D. becomes in turn the hottest hemisphere of the globe, all our winds tend more strongly to blow from the northwest toward the line C. D.-while our prevalent west winds, in March and September, are also measurably owing to this very obvious and simple course, as this line is then due north and south, or at A. B. These are the principal wellknown primal causes, which determine the perpetual flow and reflow of the great air-currents, and the peculiar climate of our globe. In a single word it is the power of the sun; and what a mighty power that is; and yet how gently, and quietly, and silently it works, through all its infinitely varied rounds and tasks! The means are as simple as the ends are various and infinite. Doubtless other local and modifying causes are as endless as they are varied; but here, alone, we find the great primal moving cause of all we behold in these incessant changes of seasons and years. DISCOURSE. It will be my object, in this discourse, to give the present impressions which all my previous readings and reflections have made on my own mind, in regard to climate, without intending to cite at length the proofs of their correctness, nor indeed to affirm it at each and all points in question. Everybody knows that we are at present in no sort of condition to present a science of meteorology, and may not be for five hundred years to come; and the best way perhaps to help it along is for each one to state frankly his own impressions, a free-will offering to the common stock. For the sake of brevity and directness, I shall, without intending to dogmatise, give my discourse wholly the dogmatic form, and let it pass for what it may seem to each one to be worth. I found myself necessitated to give some general view of the whole subject, in order to get any one of its parts into its true relations, and to lift our minds, if pos sible, out of those miserable ruts of mere authority, which, if apposite to anything on earth, surely has no place in any mere physical inquiry. Telling you what I think, may possibly aid you in finding the same great laws and facts in nature I fain would describe; but if not, my words are of no more consequence to you than the chirping of a grasshopper. Were the whole solid body of the earth made up of one homogeneous material, and were its surface covered on all sides to an equal depth with water, there can be scarce a doubt that all the currents, both of the ocean and of the air, the distribution of heat and cold, of sunshine and rain, at the same latitudes and in the same seasons of the year, would be as uniform as the return of the seasons, or as the rising and setting of the sun, or its advance from one tropic to the other-though probably the varied position of the moon, or of the other planets, would add another item of a more or less disturbing force. All, or nearly all, our present irregularities in our ocean currents and air currents, and dependent changes of heat and cold, or drought or rainfall, are due therefore to the irregularities of the earth's structure and surface, more than to all other causes combined. The solid parts of the earth are composed of a great multitude of heterogeneous or diverse materials, differing very widely in specific density and gravity in their capacity of holding or attracting water, heat, electricity, etc., while only parts of it are covered with water of very unequal depth, and other parts spread out in plains, or piled up into mountains of very unequal hight. The continents land-lock and interrupt the regular ocean flow and throw immense floods of warm water toward the poles, wholly revolutionizing the distribution of heat and cold, under the varying law of these currents, while the icebergs of the nothern seas are perpetually carting millions of tons of solid rocks, sand and earth, from the nothern pole toward the equator, in some cases, as in the banks of Newfoundland, building up whole new continents of land under our present seas. Such is also the present shape of our continents that nearly all the immense debris and wash from the action of water or frost, in our Northern Hemisphere, by the course of our rivers toward the south, or the action of glaciers and icebergs at the mouth of those flowing to the north, combined with the existing course of our present winds and ocean currents-all this debris is at last borne from north to south, or piled up, so to speak, toward the equator: while the whole Southern Hemisphere presents, so far as we know, absolutely no counterbalancing series of actions or of forces. Do our extant savans really believe that if you should shovel dirt, even with a teaspoon, from the fore end of an evenly-balanced cart toward the hind end, the cart would at last inevitably tip up, even though it might take millions of years, if the rate of removal was slow enough? If so, it is just as inevitable, under present well known conditions, that the earth must have an insensible revolution, or at least oscillation, from pole to pole, as really and inevitably as it has a more rapid daily revolution from east to west; and that, sooner or later, this inevitable movement, if continued in the same direction, would produce the astronomical change of bringing the pole where the equator now is, and throwing the equator where the poles are, even though it might take millions of years to effect the change, and though all our instruments for fixing latitude might prove quite too coarse to detect any change since they became known to man. The inevitable results of this constant change of our actual equator and polar line are quite self-evident, though not, so far as I know, anywhere adverted to. The polar diameter of the earth being twenty-six miles shorter than the equatorial diameter, should this change of poles be made at once, it would whelm each pole some thirteen miles under the seas, while the strain of the tremendous centrifugal force at the equator, on the solid and immovable parts of the globe, would generate new forces of heat and electricity all round and near the equator, and in two or more divergent lines toward the poles, which would either generate or expand and explode gasses, and produce earthquakes, volcanoes, etc., etc., enough in those regions to blow the earth all to pieces, and force it to resume substantially its present normal shape, under its new conditions. But all this does not and cannot happen at once; hence the very same phenomena are more moderately distributed over a very long series-probably of millions-of years. But they are all actually here, and daily before our own eyes, if we will but open our eyes to see them. Of course the watery and fluid parts of the earth, that lie unconfined on its surface, easily readjust and conform themselves to every change as it progresses. Hence we find the European and Greenland sides of the globe apparently sinking, as it is said, but actually rising toward the equator, and of course dipping under the new adjusted seas, to which they cannot yet conform. All history shows also that these European climates have been growing warmer from the earliest records; |