THE FARMER.

Ashburton Guardian, Volume I, Issue 4, 4 October 1879, Page 3

THE FARMER.

Why Vegetation is less Injured by ■frost in the Hills.

[G'-rrespon lout of “ Sonoma Doom- at."]

It must be new to many to leim that the so-called sheltered valleys are more liable to frost than the more exposed hill aides. Jhit this is shown very clearly in your interesting comparison of the daily sunrise and midday temperature of December, in the Santa Rosa Valley, with those of 200 feet higher elevation. Of course ly day, as every one knows, the hill is much cooler ; it is at night only that the valley becomes the colder ; hence “a warmer belt of temperature,” is hardly a correct designation, for had your comparison extended into the summer mouths, it would have shown (there are exceptions, of course) that the mean annual temperature was greatest in the valley. Still your point holds good that the valleys are more liable to frost than the hills within a certain range of elevation. Probably the first clear demonstration of this fact resulted from the establishment of meteorological stations in Switzerland. There the great height of the mountains and the narrowness of the valleys showed their difference much more markedly, and to as great a height as 5000 feet. Santa Rosa Valley is so largo and wide in comparison to the height of its surrounding hills, that the difference is neither so marked, nor can it extend to so great a height. Probably in our smaller valleys, and the great Sacramento Valley near the foot of the higher Sierra, will be found many low-lying grounds subject to night frosts even late in the spring season.

The main cause of this peculiarity in the distribution of low temperatures is to be found in the but slight heating effect of the sun’s rays on the atmosphere. The sun must first heat the soil, and the soil heats the air. Conversely the cooling of the air is also affected by the soil ; and hence the air nearest the soil is always the hottest wher the sun is shining, and the coldest when the sun is absent. For the same reason the surface air experiences the greatest changes of temperature. So it comes that the air of the valleys being hedged in by a surface of soil on every side, gets rapidly heated when the sun shines, whereas that of the hills has not only less surface for an equal quantity of air, but it is almost constantly in motion, and each new supply keeps down the temperature of the surface soil and air. The glaciers of the Sierra and the snowcapped peaks of high mountains even in the tropics, bear witness to the fact that the direct rays of the sun have but little power to heat the atmosphere, for otherwise the higher we ascended the warmer it woidd be. All solid bodies exceed air in the rapidity with which they receive and part with heat. This slowness to change its temperature is a valuable quality of air, and every gardener takes advantage of it when he covers his plants in frosty weather with old bagging, or any loose material that will confine the air about the plant. If the night is calm it is simply astonishing how slight a covering will protect a plant from a pretty severe frost. This protection, too, is almost as valuable in the forenoon when the frost is thawing out, for it prevents the sudden heating of the frozen plant, which is even more dangerous than its freezing. Few have any idea of the extreme changes of heat experienced by the surface soil! When the maximum thermometer in the air will r egister 70 or 80 degrees, one on the soil may reach 110 to 130 degrees. But even before the sun sets, and as its rays cease to heat the soil, the surface rapidly cools down, and after a calm, clear night it will be found, as a rule, from four to eight degrees colder at sunrise than the air four feet above it. How, as everyone knows, cold air is heavier than hot air, hence what forms in the valley remains there. But what of that on the hill ? As the air on the hill cools, it begins, like water, to seek its lowest level, and as the cooling process goes on, every watercourse, ditch and hollow becomes a channel down which the cold air flows just as if it was so much water. Consequently near the foot of the hill every little valley and depression of the surface becomes a little lake of the frosty fluid. Here it accumulates in proportion to the stillness of the night and severity of the frost. At the same time the hill surface, as it loses its cool air, must get a now supply, and this, of course, can only come from above, where the air of the day, being out of the reach of any solid body to cool it, has lost only a portion of its heat. So by night the soil of the hills is constantly bathed with air of a comparatively mild temperature, whilst the valleys receive of cold far more than their share.

Constitution in Sheep.

{Journal of Agriculture,)

A Cotswold sliccp or Southdown has constitution for laying on f!osh and early maturity under high treatment. Constitution in a Merino sheep will admit of all these meanings of the term and still lack what we claim as the essential purposes a sheep is kept for. A sheep must produce a fleece and a carcass. 'I he two must be in harmony and unanimity. If it has constitution to grow more wool than carcass it will he a failure. If carcass and a light fleece it will be unprofitable to its owner. If for the pastoral regions to run in the natural way with the flock, it must be constitutionally fitted io tvave l , do service, and secure a living on the range. If for the purposes of breeding on a flock in the hands of the average farmer or brooder, the broad back and well-sprung ribs are sought for. They are found to lie the bettor feeders and best to lay on flesh and grow large and heavy carcasses, and by some it is claimed heavy fleece. The claim is not as well sustained for fleeces as for oarcasses.

A Spanish merino sheep that has it perfect constitution for the purposes for which a sheep is kept will have coustitution written all over it from top to bottom. It will show it in every fibre of its fleece, in its bone, muscle, in its stand up and bright shapely appearance. In the merino the fineness of the fibie usually tells its constitutional vigor and stamina. The taxons were tender and feeble under some climatic influences and systems of treatment. So are some of the finer fibered families of the American merinos. The stronger fleeced families are the heaviest shearers and most rugged, robust, healthy, long lived of sheep. They with-

stand hardship, travel, had troafnciff unequalled by any sheep known as thoroughbred. The Cotwolds, Leicosters, and Downs are constituted for an especial purpose, and till it with perfect promptness and litness. In them the indices of vigor are as plain, as sure as in merinos. The idleness of fibre may be loss distinct in vital f rees than in the merino, but, doubtless, follow the .same rules one as the

otter. When a breeder says he breeds for constitution, he ought to say for what purpose, so that we may know just what good thing he means. If he says to grow wool, we should like to know if they grow too much wool to be healthy and vigorous with good treatment. If they are vigorous from fullness of constitutional vigor, we would like to know how much they would shear in 3C5 days—an almanac year, not a sheep shearing year for breeders who would show big fleeces. One of the handsomest samples of wool we ever received came from a ram who had taken prizes at a Western fair. I showed the sample to a judge of wool, and told him where it came from. Ho said he saw the ram, and that he was no account to any man, for he had no constitution at all. That ho saw him at their last fair, and ho stood up all the time and slept, with his oars hanging down like a sick mule. In this case there was a constitution to grow handsome hmg fibred fleeces, and not get up enough to lie down to sleep. We have seen some vigorous, bouncing, pounding, thundering rams without fleeces; at least too little to use in a vigorous flock of ewes. These had vigorous, physical constitutions, but not of a character to grow wool. There has to be a proper combination of vital forces to make up what is desirable in constitutional endowment. I once asked my family physician what he would call constitution in an animal. lie said an animal’s constitution was in its belly. Ho said constitution meant stock with its capibilitics of digesting and assimilating food to the various wants and purposes of the animal.

We think this true, but have seen a sheep with stomach vigor enough to insure health, large symmetrical carcass, but its skin so illy fitted for growing wool that for that purpose it might as well have been an imbecile scrub. Constitution is ;r tho culmination of a fostering system of treatment, and not as claimed by some who are ignorant of all laws of physical development, and think neglect and hard treatment hardens and toughens young animals. As if suffering and shivering could possibly aid in securing a perfectly full physical contour. Queer hygienic treatment for a feeble man or woman to put them out of doors in cold, stormy nights to toughen up. Under such a system the frailest ones die and the hardier ones survive, and the flock may appear more vigorous, but what a shame would come to a really intelligent man to think what a cruelty he had been guilty of in securing the dea h of bis feebly constituted animals. It’s as mean as turning the faithful, honest old horse into the road to find a living or die of hunger or thirst. w .