Page:Cyclopaedia, Chambers - Volume 2.djvu/892

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Curve Line is to be defin'd, mufl: be transferr'd,

Curve.

Transmutation of 'Plants, See Seed.

TRANSOM, among Builders, the Piece that is framed acrofs a double light Window. See Window.

Transom among Mathematicians, denotes the Vane of a Crofs-rteff 5 or a wooden Member fixed acrofs it, with a ftp-tare Socket whereon it Aides, &c. See Vane and Cross-

M-

Transom, in a Ship, is a Piece of Timber which lies athwart the Stern, between the two Fafhion Pieces, directly under the Gun-room-port.

TRANSPARENCY, or Diaphaneity, in Phyfics, a Quality in certain Bodies, whereby they give Paflage to the Rays of Light. See Light.

The Transparency of natural Bodies, as Glafs, Water, Air, ££jc. fbme have imputed to the great Number, and Size of the Pores or Interitices between the Particles of thofe Bodies : But this Account is exceedingly defective ; for the moft folid and opake Body in Nature, we know, contains a great deal more Poks than it does Matter; a great deal more, fure, than is necefTary for the Paflage of fo infinitely fine and fubtile a Body as Light. See Pore.

Arifotle, T)es Cartes, &c. place Transparency in the Rectitude or Straightnefs of the Pores ; by means of which, fay they, the Rays are enabled to make their Way through, without finking againfr. the fblid Parts, and being reflected back again : But this Account, Sir Ifaac Ne-wtm /hews, is lame ; the Quantity of Pores in alt Bodies being fufficient to tranfmit all the Rays that fall on them, howfoever thofe Pores be fituated with refpect to each other.

The Caufe, then, why all Bodies arc notTranSparent, muft not beafcribed to their wanting Rectilinear Pores' ; but either to the unequal Denfity ot the Parts ; or to the Pores being fill'd with fome foreign Matters, or their being empty ; by means of which, the Rays in paffing thro', undergoing a great Variety of Reflections and Refractions, are perpetually di- verted this way and that, till at length falling on fome of the fblid Parts of the Body, they are extinguish 'd and ab- forbed. See Ray and Reflection, &c.

Thus, Cork, Paper, Wood, &c. are Opake ; when-as Glafs, Diamonds, £f?c. are Tranjfiarent : The Reafon is, that in the neighbourhood of Parts equal in Denfity, fuch as thofe of Glafs, Water, Diamond, &c. are with refpect to each other ; the Attraction being equal on every Side, no Reflection pr Refraction enfu.es 5 but the Rays which enter'd the firfl Surface of the Bodies, proceed without Interruption quite through the Body ; thofe few only excepted, which chance to meet with the folid Parts. But in the Neighbour- hood of Parts, that differ much in Denfity, fuch as the Parts of Wood and Paper are both in refpect of themfelves, and of the Air or the empty Space in their Pores ; as the At- traction will be very unequal, the Reflections and Refractions muff, be very great ; and therefore the Rays will not be able to make their Way through fuch Bodies, but will be perpetually deflected, and at laft quite itopp'd. See Opacity.

Transparency, in Heraldry, the fame as Adumbration. See Adumbration.

TRANSPIRATION, the infenfible, or almoft infenfible PafTage of an excrementitious Matter through the Pores of the Skin ; called alio <Perfpimion. See Perspiration.

There are an Infinity of thefe tranffiratory Pores in the Skin ; the raoft confiderable whereof, are the Orifices of the Ducts arifing from the milliary Glands. See Pore and Skin.

The Caufe of Tranfpiratio?t, is the Circulation and Heat of the Blood.

Infenfible Transpiration is found very much to exceed all the fenfible Evacuations put together. Sanfforius even fhews, in hisMedicina Statica, that a Perfun lofes more in one Day by Tranfpiration, than by all the other Outlets, in Fifteen. He adds, that if the Food taken in one Day weigh Eight Pounds, the Tranfpiration will be Five of them.

Cold prevents Transpiration, by its conftringing the Pores of the Skin, and thickening the Liquors circulating in the cutaneous Glands : Heat, on the contrary, augments Tranf- piration, both by its opening the excretory Ducts of the Glands, and by its increaiing the Fluidity and Velocity of the Humours. See Cold, E£c.

M. T)odart from a Number of Experiments made for 22 Years together, affures us that we tranfpire much more in* Youth than in Age.-— In fbme Perfbns, the Tranfpiration is fo copious, that they void but very-little of the coarfer Excre- ments, though they eat very heartily.

Tranfpiration is abfolutely necefTary m the Animal Oeco- nomy, to purify the Mafs of Blood, and difcharge it of a Number of ufelefs heterogeneous Particles which might cor- rupt it. Hence it is, that upon a Stoppage of the ufual Tranfpiration, there arife fo many Indifpofitions, particularly Fevers, Agues, Itch, $$c. _

Tranfpiration is alfo of ufe to the Organ of Feeling, in that it prevents the Papilla: of the Skin from being dry'd,

either by the Air, or by the continual Touches of external Bodies.

Transpiration is alfo ufed by fome Authors, for the Entrance of the Air, Vapours, igc. through the Pores of the Skin into the Body.

Cardan, by this kind of Tra??fpirat;on, accounts for the Prodigy of a Woman, whofedaily Urinesweigh'd 27 Pounds; though all the Foods ifie took, both dry antf liquid, did not exceed Four Pounds. — - Dr. Ijaynard fufpeds fome fuch Transpiration to be the Cafe in hydropical Perfbns. See Dropsy.

TRANSPLANTATION or Transplanting, in Agriculture and Gardening, the Removing of Trees or Plants, from the Places where they were fowed or bred up, and planting them in other. See Planting andRiLi'LANTiNG, hi the Transplanting of Forejt Trees, Care is to be taken to preferve the Roots, and even the fine Hairs or Filaments thereof, with the Earth that flicks thereto ; thefe Filaments being the Mouths that fuck the Nourifhment, and transfuse it to the Tree. See Root and Vegetable.

The Pits or Foiles, into which the Trees are trans- planted, fhuuld be left open for fome time before hand, that the Rain, Frofr. and Sun may diflolve the compacted Salt, render the Earth friable, and qualify it for nourifhiug the Tree, — The fame may be done, in fbme meafiire, by burning Straw in the new Pits, and drenching the Mould with Water in dry Seafons, and by enriching the Ground with Manure. See Manure.

'Pliny was of Opinion, no Tree fbould be removed under two, or above three Years old. Cato would have none tranSplantedAt^, than Five Fingers in Diameter: But we are, now, able to transplant Trees of all Ages and Sises, without Danger.

To transplant old Trees, was reckon'd £6 difficult, that Veterem Arborem transplant are is become a Proverb for a difficult Enterprise; and yet we are informed of a Grove of Six hundred Coco Trees of So Years Growth, and 60 Foot high to the lowell Bough, transplanted by Count Afatiricej to his Paradife of Friburg: And a great Perfbn in T)evon- ftire, Mr. Evelyn tells us, transplanted Oaks, as big as Twelve Oxen could draw, tofupply a Defect in an Avenue.

For the, Transplant aticn of grown Trees, Mr. Evelyn gives the following Method, as practifed with good S-iccefs by the Lord Fitz-hardwg ■■ Choofe Trees about the Thicknefs of a Man's Thigh ^ remove the Earth from about them, cut through all the fide Roots, till the Tree may be, by force, brought down on one Side 5 fo that the tap Roots may be con- veniently come at to be cut off* with the Ax : then redrefs the Tree, and let it fland cover'd with the Mould from which it was loofen'd, till next Year, or longer 5 and by that time; it will have drawn new tender Roots fit for tranSfla'dting, and may be taken up at a fit Seafbn.

Otherwife, for very large Trees 5 e'er the hard Frofts come on, make a Trench about the Tree, at fuch Diltance from the Stem, as you judge iufficient for the Root; dig fb deep, as almoft to undermine it ; place Blocks, and Quarries of Wood to fuftain the Earth, and call in as much Water as may fill the Trench or lufficiently wet it, unlcfs the Ground were very moift before. Thus let it fland till fbme hard Frolfc bind it firmly to the Roots, and then convey it to its new Station, which may be preierv'd from freezing, by placing ftore of warm Litter in it : fo clofe the Mould the better to the ftraggfing Fibres, and place the Earth taken out of the Pit about the Root of the new-planted Tree.

The common Rules for 'Transplanting, are, i° The lighter the Soil is, the deeper are the Trees to be planted. 2 If the Soil be Gravel, or Sand, mix Clay with it, and vice verf?,* 3 The bett Seafbn, is either Offober or February j in warm, moift, clear Weather. 4 The large Roots to be abated, to prevent the Neceffity ot digging too deep 5 but the fmall Fibrous ones to be fpared. 5 In taking up the Trees to obferve how the Roots grow, and in Transplanting, to dif- pofe them in the fame Order, and place the Tree to tlie fame Afpect. 6° To defend young Trees after Transplan- tation, both from Wind and Sun, till the Roots be fix'd, and they begin to fhoot. 7* If the Soil you transplant into, be good, don't top the Trees, but lop all the Boughs to one tingle one, the moff upright and promifing among them : But if the Soil be poor, top them, and when they are ihot out again, lop off all the Branches to one. See Pruning.

Transplanting of Fruit-Trees. After a Summer's Growth of Fruit Seedlings in the Seminary, fuch are pull'd up as are above a Foot high, and transplanted into a Nurfery ; the reft to be left in the Seed-Plot till another Year. Sea Seminary.

When drawn up, the Sprigs are to be cut off, from about the Top, the Strings from the Roots, and the Extremities, both of the Top, that it mayn't run too fail upwards, and of the tap or heart Root, that it may not pals directly downwards 9 left it go beyond the good Soil. The Holes, or Pits to be fo deep, as that the Plants may fland fome what deeper in the Ground, than when in the Seed-plot 5 clofe

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