Page:Cyclopaedia, Chambers - Volume 2.djvu/771

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lower Part of this Cloud hangs,. or rather falls down, wkt W e properly call the Statu, in manner of a Conical Tube, biggeft a-top. Under this Tube is always a great boiling, ana flying up of the Water of the Sea, as in a Jet d'Eau. For fome Yards above the Surface of the Sea, the Water Hands as a Column or Pillar ; from the Extremity whereof, it fpreads and goes off, as in a kind of Smoak. Frequently, the Cone defcends fo low, as to touch the Middle of this Column, and continue for fome time contiguous to it - though ibmetimes it only points to it, at fome Dittance, cither in a perpendicular or oblique Line.

Frequently 'tis fcarce diftinguifhable, whether the Cone or the Column appear the firff, both appearing all of a fudden againft each other. Eut fometimes the Water boils up from the Sea to a great Height, without any Appearance of a Spout pointing to it, either perpendicularly or obliquely. Indeed, generally, the boiling or flying up of the Water, has the Pri- ority, this always preceding its being form'd into a Column.

Generally, the Cone does not appear hollow, till towards the End 5 when the Sea-warer is violently thrown up along its Middle, as Smoak up a Chimney. Soon after this, the Spout or Canal breaks anddifappears ; the boiling up of the Water, and even the Pillar, continuing to the lad, and for fome time afterwards 5 fometimes till the Spout form itfelf again and appear anew ; which it fometimes does, feveral times in a Quarter of an Hour.

M. de la tpyme, from a near Obfervationof two or three Spouts in Torkpire, defcribed in the c Philofophical I'ranfatli- ens, gathers, that the Water-Spout, is nothing but a Gyration of Clouds by contrary Winds, meeting in a Point or Centre 5 and there, where the greateft Condenfation and Gravitation is, falling down into a Pipe or great Tube, fomewhat like Jlrchimedes's Spiral Screw 5 and in its working and whirling Motion, abfbrbing and railing the Water in the fame Manner as the Spiral Screw docs; and thus defrroys Ships, $$c.

Thus, June the 1 iff, he obferved the Clouds mightily agitated above, and driven together 5 upon which they be- came very black, and were hurried round, whence pro- ceeded a mod audible whirling Noile, like that ordinarily heard in a Mill. Soon after, iflued a long Tube or Spout, from the Centre of the congregated Clouds, wherein he ob- ferved a fpiral Motion, like that of a Screw 5 by which the Water was raifed up. Again, Augvfi 15, 1687, the Wind blowing at the fame Time out of feveral Quarters, created a great Vortex and Whirling among the Clouds ; the Centre whereof, every now and then, dropt down, in Shape of a long, thin, black Pipe, wherein he could diftin&ly behold a Motion like that of a Screw, continually drawing upwards and %ewing up, as it were, where-ever it touch'd. In its Progrefs it moved flowly over a Grove of Trees, which bent under it like Wands in a circular Motion. Proceeding, it -tore off the Thatch from a Barn, bent a huge Oak Tree, broke one 1 of its greateft Branches, and threw it' to a great Dittance. He adds, That whereas 'tis commonly faid, the Water works and rifes in a Column, e'er the Tube comes to touch it 5 this is certainly a Miftakc, owing to the Finenefs and Tranfpa- rency of the Tubes, which do moff. certainly touch the Surface of the Sea, e'er any conlidcrable Motion can be raifed therein 5 but which do not become opake and vifible, till after they have imbibed a confiderable Quantity of Water.

The DifTolution of Spouts, he afcribes to the great Quan- tity of Water they have glutted ; which by its "Weight im- peding their Motion, whereon their Force, and even Exiffence, depends, they break and let go their Contents 5 which ufed to prove fatal to whatever is found underneath.

A notable Inftance hereof, we have in the Thilojbphical Tranfatlions, related by Dr. Richardson. A Spout in 17 18, breaking on Bmott-moor nigh Coin in LancaJJrire, the Cham- paign was immediately ovcrflow'd, a Brook, in a few Minutes, rofe Six Feet perpendicularly high ; and the Ground where- on the Spout fell, which was Sixty-fix Feet over, was tore up to the very Rock, which was nolefs than Seven Feet deep 5 and a deep Gulf made for above half a Mile 5 the Earth being raifed on either {idc in vaft Heaps.

In iP/i/^r's Time, the Seamen ufed to pour Vinegar into the Sea, to aftuagc and lay thcSpo?/t, when it approached them : Our Modern Seamen think to keep it off, by making a Noife with filing and fcratchin?r violently on the Deck 5 or, by dis- charging great Guns to difperfe it*

SPRING, in Natural Hiftory, a Fountain or Source of Living Water ariling out of the Ground. Sec Water.

The Origin of Springs or Fountains, is a Thing much con- troverted among our lateft Naturalifts.

Mcffieurs Marictte and '-Terrault afcribe it to Rains. Their rJoSrine is, That the Rain-water penetrates the Earth till fuch time as it meets a Clayey Soil or Stratum ; which pro- vino a Sufficient folid Bottom, to fuftain and flop their De- cent, they glide along it that way to which the Earth de- clines, till they meet with a Place or Aperture in the Surface Head of a River. SccStratum.
 * j* the Earth, through which they may efcape, and make the

Now, that the Rain is fufEcient for this Effect, appears

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hence; that upon calculating the Quantity of Rain and Snbw- that falls yearly oh the Trail of Ground, that is to furniOi. tor Inftance, the Water of the Seine; 'tis found, that River doesnot take upaboveone fixth Partof it. Springs ordinarily arife at the Feet of Mountains : The Reafon, fay they, is That Mountains collecl the moft Waters, and give them' the greateft Defcent towards the fame Side : and that if we fome ! times fee Springs on high Grounds, and even on the Tops of Mountains * they mnS be brought from other remoter Places* confiderably higher, along on Beds of Clay or clammy Ground, as in their natural Channels. If then, there happen to be a Valley between a Mountain, on whofe Top is a Spring, and the Mountain that is to furnilh it with Water, the Spring muft be look'd on as a Water conducted from a Refervoir of a certain Height through a fubterraneous Channel, to make i Jet of an equal or fomewhat lefs Heighti See Rain.

This Theory M. de la ffirehas taken under Examination, in its moft effential Article, and that where the Authors feem to have been the leaft diftruftful.

He has endeavour'd to find, by Experiment, whether Raiil or Snow-water could penetrate the Earth as low as the clayey Stratum : The Refultof his Inquiry,is, Thatthcy don't pene- trate even 16 Inches deep, in a Quantity fufficient to form the fmalleft Collection of Water on a Solid Bottom. Nay, this he found when the Earth he made his Experiment on* was quite naked of all Herbs and Plants ; but affoon as ever any of thefe came up, and were grown to any Bulk, fo far Was the Rain that fell, from being able to gather itfelf at the Depth of 16 Inches, that it was not fufficient even to feed the Plants, but there was a Neceflity for watering them. For the Quantity of Water expended in the ordinary Support of Plants* fee Vegetation.

Dr. Balky refers the Origin of Springs meetly to Vapours* rais'd by the Heat of the Sun, or of Subterraneous Fires from the Sea, Lakes, Rivers, (gc. Thefe Vapours, thus rais'd, he fuppofes, are by the Winds, carried over the Low-lands, to the feveral Mountains and Ridges of Mountains, and are there compell'd, by the Stream of Air, to mount with it to the Tops, where the Atmofphere being very rare and cold, retains but a fmall Part of them ; the reft is condenfed into Dew, which prefently precipitates, gleeting down by the Cran- nies of the Stones, and part of it entering the Caverns of the Hills, is gather'd therein, as in an Alembic, which being once full, the Overplus muft run down at the loweft Part of the Refervoir, and breaking out by the Side of the Hills* forms fmgle Springs, many of which running down by the Vallies or Guts between the Ridges of the Hills, and at length uniting, form Rivulets, and many of thefe meeting in a common Channel, form Rivers. See River.

Now, to fliew that Vapour is a fufficient Fund, to fupply all our Springs, Rivers, gfc. The fame excellent Author 1 makes an Elrimate of the Quantity of Vapour raifed from the Sun, by the Aflion of the Sun : The Refult of an Ex- periment be made to that Purpofc was, That the Thicknefs of Water evaporated from the Surface of the Sea, in the Space of Two Hours, in Summer-time, is one Fifty-third Part of an Inch ; which for the Eafe of Calculation, being only fuppofed to be s '„-; the Quantity of T V of an Inch will be found exhaled in 12 Hours. On this Principle, every Mild fquare will be found to evaporate, in 11 Hours, 6914 Tuns of Water, and every fquare Degree, Thirty-three Millions of Tuns. The Area of the Mediterranean then being eftimated at 160 Square Degrees, it will lofe in Vapour, in a Summer's Day 5380 Millions of Tuns.

Yet the Quantity of Vapour thus raifed, great as it is, is only the Remains of what is rais'd another Way, viz. by the Winds, which fometimes fweep the Water off, faffcr than the Sun takes it up.

To find now, the Quantity of Water the Mediterranean receives, allow the moft confiderable Rivers it receives, viz. the Iberusjlbone, Tyber, To, Danube, Neijler, Soriftbenes, Zanais and the Nile, each to furnilh Ten Times as much Water as the T'hames ; not that any of them are, in reality, fo great* but fo to allow for the lefTer Rivulets : But the names is found, by Calculation, to evacuate 20300000 Tuns of Water daily. All the Nine Rivers abovementioned, therefore, will only evacuate 1827 Millions of Tuns in a Day, which is little more than a Third of what is rais'd in that Time in Vapours See Vapour,

After all that can be faid in Favour, both of Rain and Vapour, it muft be owned, they are both ftill prefs'd with great Difficulties ; and there is ftill Room to look out for a better Theory.

The Perennity of divers Springs, always yielding the fame Quantity of Water, when the leaf! Rain or Vapour is afforded, as well as when the greateft, is a ftrong Objection to both. Mr, Derbam mentions one in his own Parifh of XJpininfter, which he could never perceive by his Eye to be diminifh'd in the greateft Droughts, even when all the Ponds in the Country, as well as an adjoining Brook, have been dry for feveral Months together, nor ever to be increafed in the moft rainy Seafons, excepting perhaps, for a few Hours, or at moll