Volume 1

An introduction to a general system of hydrostaticks and hydraulicks, philosophical and practical : Wherein the most reasonable and advantageous methods of raising and conducting water, for the watering noblemens and gentlemens seats, buildings, gardens, &c., are carefully (and in a manner not yet publish'd in any language) laid down ... / By Stephen Switzer.

  • Switzer, Stephen, 1682?-1745.
Date:
1729
Catalogue details

Licence: Public Domain Mark

Credit: An introduction to a general system of hydrostaticks and hydraulicks, philosophical and practical : Wherein the most reasonable and advantageous methods of raising and conducting water, for the watering noblemens and gentlemens seats, buildings, gardens, &c., are carefully (and in a manner not yet publish'd in any language) laid down ... / By Stephen Switzer. Source: Wellcome Collection.

    72/378 (page 22)
    any other than lodge itfelf in woolly hairy Subftances, on the Sur- face of the Earth: Befides where fuch large Cayerns are to be found, as deferib’d by the learned Nieuentyl, Fig. II. of the next Plate, is (amongft all the caverous Obfervations which we have made) hard to be found ; and if Rain does not contribute to the Ori¬ ginal and Enlargement of Springs, (which fhall be, in its proper Place, prov’d it does not,) how is it poflible that Vapour or Dews lhould do, (efpecially in England,,) where their Strength is not fo great as it is in foreign Regions. Besides, it muft be fuppos'd that all Vapour and Mill falls (as Rain does) againft one Hill, as well as another ; and why then lhould not the Hills in Salisbury Flain emit the fame Quantity of Springs, as other Countries, More than that, there muft be great Quantities of Vapour; and it ought to be continual, and immediate¬ ly fucceeding one another alfo, to fupply the Streams of a perenial Fountain, which runs ftronger in the Winter, when few or no Va¬ pours fail only in Rain, (and when there are few or none of thofe re- peated Exhalations,) than it does in the Summer, when they abound moft; fo that if thefe Vapours contribute any Thing towards the Supply of Springs, it muft be in mountanous and woody Countries, where lodging on the Summits and Tops of the Trees and Hills, they liquate and run down into the Chaims of the Earth, and after that break out, and dilperfe themfelyes for the Ufe and Benefit of Mankind, in the Manner fo often defcribM. The Curious Monfieur Marriotte (with lome others of our own Country) are of the Opinion, that Springs have their Rife from Rains only, and produce Experiments, wherein, by Calculation it appears, that the Rains which fall in a Year, are more than enough for the Supply of Springs; one of which he tells us was made at his Requeft by a skilful Man at cDijon.> who plac'd near the Top of his Houfe a fquare VelTel of about two Foot Diameter, at the Top of which there wras a Pipe, which convey'd the Rain that fell into it into a Cy~ linderick VelTel, where it was eafy to meafure it as often as it rain'd; for when the Water was in the Cyfinderick VelTel, there was yery lit¬ tle exhaPd for five or fix Days. The VelTel of two Foot Diameter, was luftain'd by a Bar of Iron, which advanc’d above fix Foot beyond the Window whereon it was placed, and fo fixed that it might receive only Rain-Water which fell immediately upon the Breadth of its opening, and that there might not any enter but what was to fall according to the Pro¬ portion of the upper Surface. The Refult of thefe Experiments was, 3 that