Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/173

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O V I

Qv-ZR-dors,, in the manege, in French, outre. A horfe Is faid to bevcr-^r.c, or outre, when his wind and ftrength are broke and exhaufted with fatieue. OvLR-flowingcf lands. The farmers of England having long obferved how great an advantage it was to meadow and pafture land, to be fometimes over-flowed by the hidden rue pf brooks, rivers, or the like, which brings the foil of the uplands upon them, and makes them need no other mending or manuring, tho' constantly mowed, have found an arti- ficial method of working the fame effect, and by it producing the fame good effect in many of their grounds without any ill one- The benefit of the natural over-flowings of meadow lands which lie in the way of floods, is in fome fort taken off by their being mbject alfo to thefe inundations at im- proper times ; and when a winter flood has caufed a fine crop of grafs, a fummer flood fometimes comes and deftroys it all before the hay-making feafon.

There are fome lands fo advantageoufly fituated, that with the aiEftance of art they may be laid under water or left dry, at the pleafure of the farmer. Thefe are the moft valuable of all grafs lands, and it is upon thefe that the far- mer practifes his artificial over-flowings ; improving them in winter by letting in the floods to have their foil for manure upon them, and keeping them dry in fummer when the grafs is long.

The artificial over-flawing of lands is commonly effected by directing the ftr earns of rivers, brooks, fprings, or land floods, or fome part of them, out of their proper channel ; but where the ftreams lie fo low as to be incapable of over-flawing the lands, they are made ufe of to turn fuch engines as may raife a quantity of water fumcient to do it. The belt and cheapeft engine for effecting this, is that called the Perfian wheel ; j which may be made of any fixe, according to the height the '■ water is to be raifed to, and the ftrength of the frream by ; which it is turned. This wheel is placed fo, that its bottom j only is immerfed in the ftream ; and there are open boxes at j its cogs ; thefe are all filled one after another with water, j which is raifed with them to the upper part of the wheel's circuit, and then naturally empties itfclf into a trough which carries it to the land.

Where there are not ftreams to turn this wheel, the farmers liave recourie to pumps, and other engines, moved by wind. Lands that lie near brooks give more frequent opportunities for thefe practices, than thofe which are near rivers ; the brooks having greater falls, and the rivers running more flow and level : but when it can be effected by the water of large rivers, the land is yet more enriched by it, thefe waters be- ing more fruitful than the others.

When the water is, by this engine, thrown into the trough, it is to be conducted by it to the higheft part of the land ; and when that is fufficiently flooded, the water is to be let into a large but not deep trench, feveral fmall ones running out of which to all parts of the land, may convey it every where, and every part may be enriched by it. It is always proper to contrive this matter fo, that the overflowing may be often re- peated, and the water quickly carried off"; for when it-is fuf- fered to lie long upon the land in winter, it is apt to breed rufhes and other coarfe plants in the ground. Some farmers graze their lands till Chriftmas, and fome longer; but as foon as fed bare, from Allhallows till lbring, that the grafs is not too high, is the propereft time of over- flowing, except that it prove a dry time in April or May. If this happen, overflowing the lands at this time will he of fmgular advantage ; for the grafs will grow three times as faft after it, in hot weather, as it would in cold. Land^-floods are the bed to overflow with in winter, and warm fattening fprings in fummer j only it muft he obferved, that the water of one operation is dried in before any more is iet on. It is always beft alfo to do it at night, that the moifturc may be foaked into the ground before the heat of the day ; for other- wife the land is often burnt. The wafhings of towns and of public highways is of great improvement to lands, as is alfo the warnings of lands where fheep feed.

All waters are not proper for this purpofe of overflowing of lauds to enrich them, the waters of coal mines and other places where there is any fulphureous mineral mixed among them, being apt to deftroy and kill the grafs where-ever they come. Thefe waters are eafily known from the healthful fpring, by their leaving a reddifh mud or fed i men t behind them where-ever they have palled ; but it is poflible, that even thefe may have their ufe when properly applied. They feem to contain avaft quantity of fait of fome kind, and we know that urine, dung, and many other things, that are moft fit of all others to enrich land, will burn up and deftroy plants, if improperly laid on in large quantities : the cafe may be the fame in thefe, and very probably thefe waters abounding in fait would do great good if they were properly blended with common water, and let in upon the lands with floods of fweet water. The farmers have gone fo far towards the prov- ing the truth of this, that they have found fome of thefe fprings, when more diftant from their fource, not only more innocent than before, but beneficial.

Cold clay lands, and other ftrong lands that lie flat, will only be improved by overflowing them with land floods, and that

only in fummer, when the feafon is very dry. Thefe lands will not bear water in fuch quantity at any other time, be- caufe it will not foak into them eafily j and it is for the con- trary reafon, that the light and fpungy lands are always moft improved by overflowing. Mortimer's Hufbandry.

OvER-grown, in the fea language. When the waves of the fea grow high, the failors call it rough fea; but when the furges and billows grow vaftly high, then it is an 'over- grown fea,

OvER-iWi?, in the fea language. A rope is faid to he over- hale.d, when drawn too itiff, or haled the contrary way.

QvZK-bale the runner, in the fea language. See Runner.

OvLK-ba'e the Jlitet, in the fea language. See Sheet.

OvER-ride, in the manege, the fame with ever-done. Seethe ar- ticle OvtR-done, fupra.

OvER-fet, or overthrow, in the fea language, A fhip is faid to over-fdt when her keel turns upwards ; which misfortune happens cither by bearing too much fail, or by grounding her, fo that flic falls upon one fide.

OvER-worked, in the manege, is the fame with over-done. It is called in French, eflrafajfer. Sec Over-^mc and Estra- passer.

OvEK-leying of children may be prevented by a machine called m-cuccw. Sec Arcuccio.

OvLEDA, in botany, the name given by Linnaeus to a genus of plants, called by Plumier valdia. The characters of which are thefe : the perianthium is a fhort and broad one-leaved cup, lightly divided into five dect and pointed legmen; s, and remaining after the flower is fallen. The flower confifts of one petal, and is of the Iabiated kind. The tube is extreme- ly long and flender, and Hands upon the germen of the piftil. It is fomewhat thicker at the top than at thebafe, and the upper lip is hollow and emarginated ; the lower is divided into three fegments. The ftamina are four filaments longer than the flower. The anther* are round ifh. The germen of tho piftil is globofe, and ftands between the cup and the flower. The ftyle is capillary, and of the length of the ftamina; and the ftigma is bifid and acute. The fruit is a globofe berry, placed in the cup, which grows larger to receive it, and is of a campaniform fhape. The feeds are oval, and are two in number. Limuei Gen. Plant. p. 295. Plumier, Gen 24..

OV1LE, among the Romans, a name given to the enclofures in which the comitia met to create magiflrates. See the article Comitia, Cycl.

OVIPARGUS (Cycl.)— The diftinclion between oviparous and viviparous creatures, feems, in the infect world, to be much lefs fixed and determinate than is fuppofed. It is evident, that fome flies, which are naturally oviparous, if they are kept from the finding a proper nidus for their eggs, be it meat, or any thing c!fe, will retain them fo long beyond their due time of exclusion, that they will hatch into worms in the body of the parent, and be afterwards dtpoilted alive on flefh, or in the manner of the young of the viviparous infects. Bartho- line gives an account in his Medical obfervations, of a hen, which, inftcad of eggs, brought forth no lefs than five living chickens ; but the died of it.

This flory of Eartholine is countenanced in a great mea- fure by a thing which happened in this kingdom; where, in the county of Norfolk, fome years after his publishing this hiftory, there was a hen, which, tho' big with eggs, could not lay, but after a time died; and people being curious to open her afterwards, there wjs found in the ovarium, a chicken difclofed from the fhell, and perfectly formed in all its parts j and probably had this been excluded in this irate, more would have followed, after being hatched in the fame unnatural manner. We have in fome authors instances given of the fame accident in the fcrpent kind, which puzzle the diftinc- tion between the oviparous and viviparous kinds.

OVIS, the fheep. The character of this genus of animal;-, given by natural! Its, is, that the covering is wool, not hair; the mouth proportionably fmalier than in the ox kind; the horns crooked, wrinkled, and often fpiral, and the papillae only two.

Trie wool of thefe animals is only a congeries of very long and flender hairs, oddly twilled and contorted, and variouflv interwoven with one another. This is a cloathing peculiar to the flieep kind, fo far as is yet known, no other animal having been feen to poffefs it : it is not, however, the cloath- ing of all the fpecies of' fheep, fome of the diftant nations having fhort hair, like that of the goat.

We at prefent know five fp-cies of this animal : I. The common Jheep of our own pafturcs. 2. The avis hticauda^ famous for the enormous fize and breadth of its tail, which often weighs thirty pounds. See the article Platycercos. 3. The ovis /I re'flchor os. See Strepsichoros. 4. The avis Afri.ana, or Mt'iczn Jlieep, which inftead ofthewoolof theow, has fhort hair like that of the goat; we have thefe often brought into England, and they feem no way different from ours but in their covering. And 5, the cvisGvinienfis, com- monly called the Angola Jheep. This is of the fize of Qurjfaepy but the hinder part of its head is more prominent, and its ears hang down. Their fcrotum is very large, and their penis placed in the middle of the belly -, the horns fmall, and bend- ing down to the eye^; and die neck adorned with a large

mane.