Meteorological
Page 86
Meteorological
Page 86
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I append an abstract of Meteorological observations, taken in Havana, on latitude forty, longitude ninety, above the sea level four hundred and seventy-five feet, by the author of this work, who is observer for the Signal Service of the United States Army: The annexed table exhibits the annual aqueous precipitation at the several points named, from observations taken during the various lengths of time, ranging from one to eighteen years. By comparing the amount of actual rainfall, the latitude, the elevation, the proximity to lakes and rivers, or the per cent of timber in the vicinity of the point of observation, we have been unable to fix any rule or cause for the variableness of amounts. There may, however, be a slight observance of increased precipitation in the line of extended river bottoms covered with timber. From our own point of observation we have abundant reason for arriving at this conclusion. Havana is situated on a high, sandy bluff, on the east bank of the Illinois river, averaging about seventy feet above the river. The west bank of the river is low bottom lands, covered with timber, and about an average of four miles wide, and they are bounded on the west by the wooded bluffs of Fulton county. About twenty miles south of this point the Illinois river receives the Sangamon river from the northeast, forming the southeastern boundary of Mason county. The bluffs and bottoms of the Sangamon are similar in structure and extent to those of the Illinois. After a residence of eighteen years at this point, and noting the rainfall carefully on my meteorological record, I am fully convinced that our summer rains, usually from the southwest, divide at the confluence of these rivers, and timber belts that fringe their shores, leaving the central portion of the county with much less rainfall than would be shown by observations taken in a central line of the timber belts:
Height above the sea of several localities in Illinois, taken by the writer at the solicitation of Prof. Henry, of the Smithsonian Institution, for that institution:
The greatest amount of rainfall during any one month was June, 1872, when the enormous amount of 9.83 inches fell, and nearly all of that excessive amount during the first six days of the month. The lest amount was in October, 1872, and in August, 1873, when 0.84 and 0.89 of an inch respectively fell. The maximum temperature for August, 1873, was 103 deg., and the maximum for October, 1872, was 86 deg. The mean temperature for August, 1873, was 75 ½ deg., and for October, 1872, it was 50 deg. These temperatures, compared with the corresponding months of other years, show no excessive degrees of temperature over the same month, when the amount of rainfall was greater or of an average amount. [See table.] My record shows, however, considerable cloudiness, and consequently an obstruction of sunlight, with the natural result, as a consequence, of a less generation of heat, as set forth and illustrated in a succeeding part of my subject. Thirty-eight and three tenths inches is the average rainfall for a group of stations in this State, whose aggregate terms of observation amount to ninety-nine years. Every increase in the temperature of the atmosphere of 27 deg. Doubles its capacity to hold moisture, consequently those localities most subject to frequent changes of temperature are liable to the most rainfall, more, also in a southerly than in a northerly locality, because the high temperature makes the atmosphere capable of a larger amount of moisture, Temperatures are less changeable in the vicinities of the great lakes than farther inland, consequently the aqueous precipitation is more uniform in Northern than Central Illinois. I append, from reliable sources, some of the most remarkable temperatures of the earth, that the reader can compare his own locality with that of his more or less favored neighbor. Thibet, in Central Asia, has valleys between her snow-capped mountains where they endure a heat of 150 deg. Fahrenheit; Senegal, in South Africa, and Gaudaloupe, in the West Indies, 130 deg.; the Desert of Sahara, 130 deg. During the day and extremely cool night; Persia, 126 deg.; Calcutta and the Delta of the Ganges and Central America, 120 deg. is the limit. In the jungles of Afghanistan and the deserts of Egypt, 110 deg.; Cape Colony, in Africa, Greece in Europe, Utah in America, 105 deg. is the maximum; Arabia, 105 deg.; and Montreal and Quebec endure the same summer temperature. New York, Spain, Upper India, Canton in China, Island of Jamaica and the Southern United States, 100 deg.; Sierra Leone, in Africa, Guinea, in South America, and the Island of Ceylon, 93 deg.; France, St. Petersburg, Denmark, Belgium, Burmah, Shanghai, Sandwich Islands, Buenos Ayres and Trinidad, 90 deg.; Nova Scotia, 87 deg.; England, Ireland, Sicily, Siam and Peru, 85 deg.; Pekin, in China, and Portugal 80 deg.; Liberia, 77 deg.; Australia, Scotland, Italy, Venezuela, and Maderia, 74 deg.; Prussia and New Zealand, 70 deg.; Switzerland and Hungary, 67 deg.; Bavaria, Sweden, Northern Liberia, Tasmania and Moscow, 65 deg.; Norway, Greenland and New Foundland, 60 deg.; Central Scotland, Orkney Isles, Patagonia and Falkland Islands, 50 deg.; Iceland, 45 deg.; Nova Zembla, the last we shall note, whose extreme summer heat rarely comes above freezing point, or 34 deg. Maximum. In all this range of territory, climate and temperature, wherever the foot of man hath trod, or eye could reach, from the scorching vales of Thibet to the inhospitable regions of Nova Zembla, in the deserts of Sahara, or the perpetual snows of Greenland and Labrador, the scenery is relieved and brightened by the growth of indigenous plants and flowers, cheering the wanderer in the desert, and the inhabitant of the snow hut, casting beauty and fragrance on the sand or on the snows, varying their form to suit their situation, from the fleshy prickly Cactii of Mexico, to the Algea tribe that redden the polar snows.
LIGHT AND HEAT. These various forms of energy are mutually convertible, and we can express the terms of each in the terms of any other. Dr. Tyndall, in considering the important influence exerted by solar radiation on the phenonema of life, says: "Each drop of rain or flake of snow, each mountain, streamlet or brimming river, owes its existence to the sun's rays. It is by the sun's rays that the waters of the ocean are lifted in the form of vapor in the air, and it is by the condensation of this atmospheric moisture that every drop of running water on the earth's surface is formed. The balmy breeze and the devastating tornado are alike the product of the changes of atmospheric temperature, while the gradual crumbling of the everlasting hills, and the consequent formation of stratified rocks are sublime illustrations of the might of the actions which, during geological ages, the sun has poured out on the earth. Nor is this influence confined to the inorganic world; no plant can grow, now animal exist, without the vivifying influence of the sun's rays. The animal derives his store of energy from the plant necessary for the maintenance of life, from the force locked up in the vegetable on which it feeds. The food of the animal undergoes combustion or oxidization in the body, and the heat thereby evolved is converted into mechanical energy, so that the same laws which regulate the labor of animals, regulate the work done by the steam engine supplied with fuel. The animal draws its stores of energy from the plant, and where does the plant obtain the supply necessary for its growth?" "The source of power in the plant is found in the sun's rays. It is the sun's rays that enables the plant to grow; for the growth of the plant consists, chemically, of a decomposition or splitting up of the carbonic acid gas which exists in the air, into its simplest constituents, the carbon assimilated for the building up of the vegetable tissues and the oxygen sent back into the air for the subsequent use of animals. To effect this separation of carbon and oxygen, a very large expenditure of force is necessary, and this energy is supplied by the sunlight." How beautifully harmonious the discoveries of modern science with the profound depths of revealed truth, and how obtuse is man's apprehension of these truths, till forced upon a slow-to-be-convinced judgment by the practical deductions of science. "And God said, let there be light, and there was light; and God saw the light that it was good, and God called the light day, and the darkness (or absence of light) He called night." "And God said, let the earth bring forth grass, the herb yielding seed and the fruit tree yielding fruit of its kind, whose seed is in itself." "And God made two great light, the greater light to rule the day and the lesser light to rule the night." "But there went up a mist from the earth, and watered the whole face of the ground." The atmosphere surrounding the globe had been called into existence-its constituent elements as they now exist. Light was created to generate heat that vegetation might clothe the earth. After vegetation, and next in order, there "went up a mist from the earth, and watered the whole face of the ground." The laws of nature, as constituted, made any other order of creation impossible. Light must combine with the elements of the atmosphere before the vegetable creation could exist. The vegetable, in connection with air, light and heat (heat being a result of air and light), must exist before vegetable growth could occur or animals inhabit the earth; and the consequent rainfall recorded in our last quotation is the inevitable result of the action of heat on the aqueous element. There seems to exist more largely those elements of the atmosphere that combined with light to form heat in the lower stratas-more in the deep valleys than on higher tablelands, or on the hills, and not existing at all above the snow line; hence, snow does not melt in the full sunlight of meridian day, even under a tropical sun. On the Andes the snow line varies from 14,000 to 17,000 feet. On the mountains of Colorado, snow begins at 12,000 and increases in quantity to the extreme height of the tallest peaks, or 14,250 feet, though in August the extreme heat of the deep valleys rises up, when the light of the sun is withdrawn, and the snow is melted to nearly or quite the extreme height. In the ocean, water and salt are mixed together most intimately, yet the heat raises the water through the atmosphere and leaves the salt. Every increase of twenty-seven degrees of temperature doubles the capacity of the atmosphere for holding moisture; consequently, the large amount of rain at the points of greatest heat and evaporation, and the distribution and precipitation of rain from greatly heated localities to colder ones by the action of the winds, and by other causes, and precipitated by counter-currents of cold air.
INFLUENCE OF VEGETATION. Here, therefore, is a constant circulation of benefits between the two great provinces of organized nature. The plant purifies what the animal poisoned, and in return the poisoned or contaminated air is more than ordinarily nutritious to the plant; but it must be remembered that the renovating, purifying influence exerted by growing vegetation on the atmosphere, can only be done under the influence of light, and ceases altogether in the night, or if the light of the sun be withdrawn. This is a general characteristic of all plants; for, with all their manifold diversities of form and appearance, they are all constructed on the same general plan, " and are living witnesses and illustrations of one and the same plan of creative wisdom in the vegetable world." Plants work only under the influence of light. "There is conversion by the vegetable of foreign dead mineral matter into its own living substance, or inorganic matter, capable of becoming living substance." To do this is the peculiar office of the plant, "and it is done by the plant by the action of its green parts only, and by them only under the influence of light of the sun. The sun in some way supplies a power which enables the living plant to originate these peculiar chemical combinations to organize matter into forms which alone are capable of being endued with life." The process is all the same, whether the plant is making a direct immediate growth or laying up material for future use. The principal ingredient laid up by plants is starch, in the form of minute grains in the cells of the plant. Some plants make these accumulations in the roots, as the parsnip and the carrot; some in shoots or underground growths, for instance, the potato, while the onion and lily deposit in the embryo leaves, and the cactus family generally in their fleshy leaves and stems with green coverings, and only under the influence of light.
ORIGIN OF HEAT. The valleys in Thibet, in Asia, endure a temperature of 150 deg. F. in the shade during the day, and as the sunlight is withdrawn the warm air rises up, and the cold, dense atmosphere from the mountains covered with snow, settles in its stead, the inhabitants, who were during the day almost in the condition of the Hebrew children, now find it necessary to retire to rest under thick coverings. Another proof that heat does not emanate from the sun is found in the experience of every green-house man and florist. The temperature is raised to a high degree under his glass, and there it seems to be imprisoned, being unable to return, although it apparently came in through that dense medium unobstructed. The facts of the case divest the subject of all mystery. These are, that the sunlight penetrates the glass, and the heat is formed beneath by a union of the light with some element or elements of the air, and instead of being a prisoner in confinement, it is simply an occupant of the place where it first had an existence in its present form. The eye in its complex and multifarious forms can only be the recipient of light, and cannot endure heat, hence it receives light only. The lenses of the telescope and the human eye bear a complete resemblance to each other in their figure, their position, and in their power over the rays of light, viz: in bringing each pencil of light to a point at the right distance from the lens, to-wit: in the eye at the exact place where the membrane is spread to receive it. Two things were wanted to the eye that were not to the telescope, at least to the same degree, and these were the adaptation of the organ to different degrees of light, and to the vast diversity of distance at which objects are viewed with the naked eye, as from a few inches to many miles. These difficulties are not presented to the maker of the telescope. He wants all the light obtainable, and never directs his instrument to objects near at hand. In the eye both cases are provided for, and for the purpose of providing for it a subtle and appropriate mechanism is introduced to exclude the excess of light when it is excessive; and to render objects visible under obscurer degrees of it, the hole or aperture of the eye is so formed as to contract or dilate for the purpose of admitting a greater or less number of rays at the same time. The chamber of the eye is a camera obscura which, when the light is small, can enlarge its opening, and when too strong can contract it without any other aid than its own machinery, which machinery is operated by the light itself and self-regulating. Inasmuch as this organ has to operate under so many different circumstances, with strong and weak degrees of light upon their objects near and remote, and these differences demanded, according to the laws by which the transmission of light is regulated, a corresponding diversity of structure through which the light passes, that they be larger or less, the lenses rounder or flatter, or that their distances from the tablet on which the picture is delineated should be shortened or lengthened. This being the case, and the difficulty to which the eye was adapted, we find its several parts capable of the most sudden changes, and mechanical and artificial apparatus provided to produce these changes. These changes are made, this complex machinery is operated on by the action of light itself, which is another of its wonderful properties and adaptations of means to ends. When light enters the eye it falls on a dark background, and hence does not generate heat, as though reflected from a light surface in the air. The tropical sun shining on the dark colored races of the tropics is another illustration of the same thing. The negro will endure more heat than the average inhabitant of the temperate zone. The eyes of birds possess the powers and properties described in the human eye to a more marked degree, as their necessities require it to be so. The eyes of fishes compared with terrestrial animals exhibit distinctions of structure adapted to their state and element. The iris in the eyes of fishes do not admit of contraction or expansion. This is a great difference, and the reason is probably that the diminished light in the water is never too strong for the retina. Some interesting differences, also, in the eyes of the different varieties of fishes might be interesting, but enough has been said to illustrate this part of the subject.
CONCLUSION. "We will not here inquire if there be anything inherent in the system, or in its past history, prophetic of universal dominion," but no digress as to inquire if there are disagreements between science and revelation. The system of truth revealed to us in the book of nature and the book of revelation, both emanating from the same Great Author, cannot conflict and both be true, hence disagreement is rendered an impossibility. Empires like China and Japan, embracing more than one-third of the population of the globe, resist alike the advancement of science and Christianity. Idolatry and stolid ignorance alike resist the march of truth. Millions of men are idolators, other millions followers of Mohammed, and still millions more the worshippers of Bramah and Budah; but a single Christian nation outweighs them all. "Let there be light," was spoken by the Creator before the dawn of creation's morn, and science has continued to re-echo that grand acclaim to the teeming millions who people this vast globe. The lights of science are burning brightly on the broad domain of our own favored land, from the Atlantic to the Pacific, from Alaska to Panama; in the isles of the ocean, and in the darkest regions of Paganism, doors have been opened to our science, our commerce and our language. About the time the reformation dawned on the darkness of Europe, the polarity of the compass was discovered, and spread the light with the expanding commerce of the nations. Then came the printing press, "every pull of which casts rays of light athwart the gloom," and the world is learning the sciences that speak just what the bible speaks. No fact recorded by the sacred historians has been so favorite a subject of cavil as the Mosaic account of creation, before quoted. The objectors fail to remember that Moses described these things optically and not physically. Modern science proved that the phenomena of the heavenly bodies are not at all contradictory to the Mosaic history. Modern opposers of revelation have objected that Moses talks of light before there was a sun, and calls the mood a great light, when every one knows it to be an opaque body. But Moses seems to have known what modern science did not until very lately discover, and therefore does not call either sun or moon a great light, but luminaries or light-bearers. Will the objectors look into their Greek, Hebrew or Latin bibles, and their faith will be increased in reference to Moses' attainments in science. Though the moon is not a light itself, yet is that planet a light in its effects, as it reflects the light of the sun to us. But the sun and the moon are with propriety called great, not as being absolutely greater than all other stars or planets, but because they appear greater to us, and are of greater consequence and use in the world. And now, after all the philosophy and improvements in astronomy, we still speak of the light of the moon, and the rising and setting of the sun. The man who in a moral, theological or historical discourse should use any other language, would only render himself ridiculous. Hence we say that Moses' description of creation in Genesis is not in conflict with science in its best discoveries, but confirms it; that he speaks optically and not physically; and that we place implicit and impartially in detail, the utmost reliance on the Mosaic record as a proof of our position on the origin of light, the generation of heat, cause of evaporation and its effect, the philosophy of vegetable life and plant growth, and the consequent assimilation of force in the animal kingdom. Anciently the sciences were locked up in the hands of the priesthood, and unknown to the masses, and hence not reduced to the practical wants of life. To do so was spoken of as degrading science. Not so in modern times; the masses are educated, and in advance of the priesthood in all the literary, scientific and mechanical progress of the age. And I believe that to-day the heaviest drawbacks, the most ponderous dead weight that militate against the progress and advancement of the light that blazes in all its effulgence with more than meridian splendor from the midday sky of the nineteenth century, is to be found in the bigotry and lack of education and of general intelligence of the priesthood. We do not assert this in the Spirit of faultfinding opposition, but with regret that such a state of affairs should exist in our country; and the world hopes and expects their speedy removal, by a wider diffusion of the truths of science and the bible. |
