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evaporated from the earth; as, her meteorological operations : b; therefore, the sun advances to the former the atmosphere is rarewards the meridian, and for an fied, and consequently becomes hour or two afterwards, he dries light; by the latter it is condensed, and warms the air, and conse- and consequently becomes heavy. quently the rain is likely to cease Hence probably the old remark, at that time. But if there should that a storm generally follows a be so much water in solution in calm ; for during a calm the air is the aimosphere, that the heat of rarefied and expanded, and the the sun is not sufficient to produce cold air will rush forward in a these effects, in that case the rain strong current to restore the equiwill probably continue some hours librium, and necessarily produce longer.
what is generally called a gale of “Violent winds generally abate wind, the violence of which also towards sun-set.
will of course be in proportion to “ If we admit that wind is only the degree of the preceding rarea current of air put in motion by faction. the rarefaction of the atmosphere “ For these reasons, the baro, in some particular place, and that meter falls suddenly whilst the air this current of air is moving to. is expanded before a gale of wind, wards the point of rarefaction to and rises again gradually as the restore the equilibrium, we must condensed air returns; and the suppose, that as the sun declines gale in like manner by degrees the rarefaction will diminish, and subsidies. consequently the velocity of the “ It must however be observed, wind decrease. But this observa- that an extraordinary fall of the tion, in my opinion, rather applies mercury will sometimes take place to the temperate than to the torrid in summer, previous to beavy. zone; for in whirkvinds and hur- showers of rain, particularly if ricanes the contrary may very often attended with thunder and lightoccur.
ning; but in spring, autumn, and “When the wind follows the winter, the sudden extraordinary course of the sun, it is generally descent of the barometer indicates attended with fair weather. This principally violent wind. frequent and regular change of “Upon these principles likewise wind, which is never more than a we may account for the rise and moderate breeze, proves that there fall of the barometer in the different is no point of considerable rarefac- zones. In the torrid zone, partition near; and, therefore, the cur- cularly at St. Helena and the islands rent of air follows immediately the of the Pacific Ocean, it seldom sun's course: it always happens in varies more than three-tenths; at summer, but very seldom when Madras about five-tenths; in the the sun's meridian altitudie is less south of Europe not more than than forty degrees.
one-inch and two-tenths; in Eng: “ The changes which take place land it varies two inches and a half, in the atmosphere are principally and in Peter burg three inches marked by the rising and falling of four-tenths. In the two first the the barometer, which apparently temperature of the atmosphere is is caused by heat and cold, the not suhject to much variation, and hands with which nature periorms never to any great degree of condensation. In the third, reckon- commonly early in the morning; or ing from the tropics to the latitude late in the evening, than at noon, of forty, the atmosphere may some- which seems occasioned by the obtimes be suddenly condensed by vious causes of the atmosphere currents of cold air from the north, being condensed by the cold of the and still more so in England. But night, and rarcfied by the heat of the greatest variation must neces
the day. sarily take place on the continent " The following observations of to the northward, where, during Mr. Patrick seem conhrined by the summer, the weather is as hot experience. as within the tropics; and, in win- "1. The rising of the mercury ter, the thermometer, for many presages, in general, fair weather, weeks, continues several degrees and its falling foul weather, as rain, below the freezing point.
snow, high winds, and storms. “ The thermometer also, which “ 2. In very hot weather the measures the degree of heat in the fall of the mercury indicates thunair near the earth, will contribute der. towards denoting when changes " 3. In winter the rising preare likely to take place in the lower sages frost; and in frosty weather, regions of the atmosphere; the if the mercury falls three or four hygrometer distinguishes the quan- divisions, there will certainly foltity of moisture in the atmosphere, low a thaw; but in a continued and the electrometer will point out frost, if the mercury rises, it will the quantity of electricity which certainly snow. prevails in it.
“4. When foul weather happens “ The words generally engraven soon after the falling of thic meron the plates of the barometer cury, espect but little of it; and, rather serve to mislead than to on the contrary, expect but little inform, for the changes of the fair weather when it weather depend rather on the shortly after the mercury has rising and falling of the mercury, risen. than on its standing at any parti- 3. In fuul weather, when the cular height. When the mercury is mercury rises much and high, and as high as fair, or at thirty degrees, so. continues for two or three days and the surface of it is concave, before the foul weather is quite beginning to descend, it very often over, then expect a continuance of rains; and on the contrary, when fair weather to follow. even the
mercury is at twenty-nine “6. In fair weather, when the degrees, opposite to rain, when mercury falls much and low, and the surface of it is convex, begin- thus continues for two or three ning to rise, fair weather may be days before the rain comés ün, expected. These circumstances then expect a great deal of wet, not being known, or not duly and probably high winds. attended to, is the principal cause «Io7. The unsettled motion of that farmers and others have not a the mercury denotes uncertain and proper confidence in this instru- changeable weather. ment.
• But to these remarks may be “ It must also be observed that, added, that, when the barometer cæteris paribus, the mercury is higher suddenly falls two or three tenths, in cold than in warm weather, and without any material alteration in 1801.
the thermometer, and the hygro- weather-glass, closes its leaves meter is not much turned towards before rain; and the down of the moist, a violent gale of wind may dandelion is much affected by be expected. When the hygro. moisture. meter inclines far towards moist, “ All wood, even the hardest with only a trifling descent in and most solid, swells in moist the barometer, it denotes a pass, weather. The vapours insinuate ing shower and little wind ; and themselves into the pores of trees, when the barometer falls consi- and also into the wood-work of derably, and the hygrometer turns houses. much towards moist, the thermome- “Insects and reptiles of all kinds ter remaining stationary, and rather seek or avoid rain according 10 inclined to rise than fall, both vio- their respective liabits, by these lent wind and rain are likely to means giving notice of every change follow in the course of a few hours. of weather.
“ It is a well-known fact, that “ General or common Prognostics of before rain, particularly in summer, the Weather.
a strong smell is perceived from Amongst these we may reckon drains and common sewers, as well such as are derived from birds, as from every other body emitting beasts, insects, reptiles, and plants; a great quantity of effluvia. Durto which might be added great parting fair weather, even in summer, of the wood-work in houses, as the atmosphere readily absorbs all doors, windows, window-shut- the vapours and exhalations from
the earth until it is completely satu“ Birds in general retain in the rated, and consequently the estuvia quill-part of their feathers a quan- from the bodies which emit then tity of oil ; which, when they feel will then be confined and ascend an extraordinary degree of mois. in a narrow compass, like the ture in the atmosphere, they ex
smoke of a chimney in dry weapress, by incans of their bills, and ther, almost perpendicularly; but distribute it over their feathers, to when the air is saturated with secure their bodies against the moisture, and beconies rarefied and effects of an approaching shower. expanded, as it always does before
" Swallows, in pursuit of the flies rain, the volume of air containing and insects on which they prey, the effluvia will be extended hokeep near the earth in wet wea. rizontally, and diverge from these ther; and in dry weather, from the different bodies as from a centre, same cause, they fly much higher. ' and will be sensibly perceived on
" Domestic animals, as cows and all sides, but will of course be must sheep, but particularly the latter, perceptible on that to which the on the approach of rain, feed with current of air or wind moves. great avidity in the open field, and “ In winter, when the thermoserire near the trees and hedges as meter is between thirty-four and soon as they are satisfied. In fine forty degrees, the air being in a state weather they graze and lounge of condensation, and the running about, eating and resting aller- water being warmer than the land, nately with apparent indifference. a mist or fog may be seen rising
“ The pimpernel, commonly above the river, particularly wlien called peep-a-day, or, shepherd's the air is cold and clear; but this
vapour is no longer visible when may afford both amusement and the river is frozen; for though the instruction, particularly in meteoice be subject to evaporation, it rology; but to observe them with does not yield so much vapour as due attention, we must quit the water; and the water, in parting busy scenes of life; "and thus our . with its caloric in the moment of 'lives exempt from public haunts, freezing, warms the surrounding 'find topgues in trees, books in the air.
running brooks, sermons io stones, “To the philosopher all objects in and good in every thing." nature, both animate and inanimate,
LIGHTS are diseases in- the same time, the carth being ing them variously. In some the the current of air will come in leaves only are withered, in others strong gusts from the ocean, and the leaves and blossoms; some do produce those winds, which are not lose much either of their colour generally known by the name of or shape, others again seem shri- the equinoxial gales. The blosvelled or scorched, and very soon soms of those fruit-trees, therefore, entirely perish. Some persons which are not sheltered towards suppose, that blights come from the westward, will be blown off the eastward, and others from the before the fruit is formed, and prowestward ; and by many it is be- duce those blights which affect the lieved that they are frosts which blossoms and not the leaves. But descend from the upper regions of the current of air which comes the atmosphere. Insects are often from the eastward about the same found on the trees which have season, being excessively dry, absuffered from blights, whence it is sorbs all the moisture, both on the also imagined that some kinds of leaves and fruit, and produces that blights proceed from immense parching kind of blight which number of insects, which are bred curls up the leaves and destroys in particular places, and are trans- the fruit, and sometimes kills the ported by the winds towards the trees themselves. When the leaves plants which they destroy.
are parched, and the texture of Experience confirms the exist. them is broken, the perspirable ence of almost all these different matter becomes viscous, and by blights. We will offer a few con- adhering to the leaves affords both jectures on the subject, and at- shelter and nutriment to insects. tempt to explain from what causes When the young are hatched, they they are derived.
begin to prey upon the leaves, and " In the spring vegetation com- if they are not removed in due mences, and frequently in the time will ultimately destroy the morth of April the peach and nec- trees. I was led to make these retarine trees are in blossom. About flexions from observations made in
my own garden for seven years both which my wall is sheltered, I successively. On the north side am much disposed to conclude, of it is a stone wall, coped with that the blights from which they brick, of one hundred and thirty suffer are to be ascribed to those yards in length and twelve feet causes. high. Against this wall are plant- " It sometimes happens that the ed eighteen peach and nectarine nectarine-trees have been slightly trees, one Cressan pear, and two attacked by a blight, and the or three small vines, kept very peaches have escaped, though closely pruned. The trees are planted alternately with the latiet planted in a border of four feet in 'on the same wall. As the blight breadth, on a soil of loam and parched and curled the leaves, i black earth, of about twenty inches suppose that it came from the east depth, on a gravel. The soil is in the manner above described; nearly the same as the rest of the and it is probable, that this current gardens in the valley near Cardift. of air attacked the leaves of the The wall is built of the same mate- nectarines without injuring the riáls; of the same height, and its peaches, on account of the superior aspect corresponds nearly with that delicacy of the leaves of the forof other gardens, being about S. by mer, or perhaps from their being W. or S. S. W.; and the trees are more porous, and suffering more pruned by the same person who from evaporation. This blight, works for many other families in however, has only once occurred; the neighbourhood. Nevertheless, these remarks, therefore, are inwhen their trees entirely fail, these tended as meie suggestions or hints have borne regularly every year
on the subject. It the nectarines ' four times as much fruit as we should frequently suffer, and the choose to leave on the trees to peaches never, it may probably be ripen; and the fruit, so abundant, ascribed to ulic different qualities of has likewise been of the best qua- their leaves; but if the contrary lity. The trees are about four-should happen, we must then reteen years old, and consist offer to some other cause. the Magdalene, Rambouilet, Royal “Awall with a projecting coping George, and Newington peaches, is supposed to be favourable 10 and the Brignon, Etronge, Mur- fruit - trees, in protecting their say, and Roman nectarines. It leaves and blossoms from the de. may be proper to observe, that scent of cold dews, which early in no manure is used to these trees, the spring are accompanied with but every year a small quantity of frost; but this plan does not seem pure virgin earth is put on the bor- to me entirely free frown objection; der, which is also dug in a good at least it appears necessary to spade deep, both in spring and have this a moveable fence, for autumn.
when the danger of the frost is “Astherefore the trees in my own over, the descent of the dews are garden have never failed, and there necessary, to refresh the trees and appears no difierence between swell the fruit, which will never them and those belonging to my come to perfection from being arneighbours, excepting that their tificially watered. Besides in hot walls are exposed to the equinox- dry weather the expense of labour ial gales and the east wind, liom for this kind of work would be