Page:Cyclopaedia, Chambers - Volume 1.djvu/1032

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lumhut the firfi Hint to attempt a Difcovery of the IVefl- Indies, in which he fucceeded.

For the Con(lruBiou of the feveral Kinds of Hydrographi- cal Maps ; See Chart.

For their Ufesy See Sailing.

HYDROGRAPHY, that Part of Geography which con- fidcrs the Sett 5 principally, as it is navigable. See Sea and Geography.

Hydrography teaches how to defcribe,and meafure the Sea; gives an Account of its Tides, Counter-tides, Currents, Soundings, Bays, Gulphs, s£c. as alfo its Rocks, Shelves, Sands, Shallows, Promontories, Harbours, Distances, l$c. from Fort to Port, with all that is remarkable, either out at Sea, or on the Coaff.

Some of the belt Authors ufe the Term In a more ex- tenfive Senfe 5 fo as to denote the lame with Navigation.

In this Senfe Hydrography includes the Docf rine of Sail- ing ; the Art of making Sea Charts, with the Ufes thereof; and every thing neceffary to be known, in order to the fafclt and moll expeditious Performance of a Voyage. See Na- vigation. S?e alio Sailing, Chart, £J?c.

Hydrography is rhe nioft perfect of all the Mathematical Sciences ; there being fcarce any thing wanting to its Per- fection, but the Diicovery of the Longitude. See Lon- gitude.

The Jefuits Ricciolns, Foamier, and Zte Chales, are the principal Writers on the Subject of Hydrography.

In France, they have ProfcfTors of Hydrography eUabUlVd in all their Sea Ports, who are to inllruct the Youth intend- ed for the Sea, in all the Parrs of Navigation, Sailing, Steering, gfc. with the feveral Branches ofMathemaricks neceffary thereto ; as Arithmetick, the Doctrine of the Sphere, Trigonometry.

They are Royal Profeffors, and teach Gratis ; having Salaries allow'd them by the King. They are alfo charg'd with the Examination of Pilots, i£c.

The Word is compounded of the Greek, &%, aqtta, Wa- ter, and yeyjco, fcribo, defcribo, I write, deicribe.

HYDROMANCY, Hydromantia, the AS or Art of divining or foretelling future Events by means of Water. See Divination.

Hydromancy is one of the four general Kinds of Divina- tion ; the other three, refpecting the other Elements, viz. Fire, Air, and Earth, are denominated tPyromattcy, Aero- mancy, and Geomancy,

Varro mentions the Verfmns as the firft Inventors of Hy- dromancy ; adding, that Numa Vompilias and Tythagoras made ufe thereof. See Hydatoscopy.

The Writers in Opticke, furnifh us with divers Hydro- mantis Machines, Veffels, £jc.

To ConftruB a Hydromantic Machine, by Means whereof en Image or ObjeS flmll be remov'd out of the Sight of the SpeBator, and, rejlor'd again at fleafure ; without altering the "Pojition either of the one or the other.

Provide two Veffels A BF and CGLK (Tab. Hydrau- licks, Fig. 31.) the uppermoft fill'd with Water, and iii- ftain'd by three little Pillars, one whereof, BC, is hollow, and furnim'd with a Cock B.

Let the lower Veffel CL be divided by a Partition HI, into two Parts ; the lower whereof may be open'd or clos'd by means of the Cock P.

Upon the Partition place an Image, which the Spectator in O cannot fee by a direct Ray GL.

If now the Cock B be open'd ; the Water defcending into the Cavity C I, the Ray G L will be refracted from the Perpendicular GR to O ; fo that the Spectator will now fee the Image by the refracted Ray OG. — And again, Phut- ting the Cock B, and opening the other P, the Water will defcend into the lower Cavity HL ; whence, the Refraction ceafing, no Rays will now come from the Object to the Eye. — But, fhutting the Cock F again, and opening the other B, the Water will fill the Cavity again, and bring the Object in Sight of O afrefh. See Refraction.

To male it Hydromantic Veffel, which fbatt exhibit the Images of external ObjeBs, as if fmimming in Water.

Provide a Cylindrical Veffel AB CD, (Tab. Hydraulicks, Fig. 32.) divided into two Cavities by a Glafs EF, not per- feaiypolifh'd: In G apply a Lens Convex on both Sides ; and in H incline a plain Mirror of an Elliptic Figure under an Angle of 45° ; and let IH and HG be fomething lels «han fheDiftance of the Focus of the Lens G ; fo that the Place of the Images of Objects radiating thro' the fame

may fall within the Cavity of the upper Veffel. Let

the inner Cavity be blacken'd, and the upper fill'd with clear Water.

If now the Veffel be difpos'd in a dark Place, fo as the Lens be turn'd toward an Object illumin'd by the Sun ; its Image will be feen as fwimming in the Water,

The Word is Greek, compos'd of Kjfcf, Water, and ytonjldi Divination.

HYDROMEL, a Drink made of Water and Honey ; call'd by the Greeks nfMx.eg.iw.

Hydromel is Honey diluted with a fufficient Quantity of Water, and fermented by a long and gentle Heat. See Honey. .

Under the Clafs of Hydrmrels come our Mead, and Me- theglin. See Mead and Metheglin.

Hydromel is either Simple, call'd alfo aqueous, where Honey and Water are the only Ingredients, which may be prepar'd at any Time ; or Compound, when other Drugs are added, to improve and exalt the Flavour and Virtues.

'Tis particularly call'd Vinous Hydromel, when it equals the Strength of Wine ; which it is brought to do, not only by the great Quantity of Honey us'd in it, but alfo by it3 long Coction, infolation, &c. This is only made in the Heat of Summer.

Vinous Hydromel, (the fame with what we ofherwife ral? Mead, fjjf.) is made of Rain Water and the bed: Honey boil'd together, and skum'd from Time to Time till they become of a Confidence to fuflain an Egg. This done, the Liquor is expos'd to the Sun for 40 Days, to difpofe it to ferment ; then, adding fbme Spanijh Wine, and keeping it two or three Months, it acquires a Flavour fctrce inferior to Malmfey. — It fuddles readily ; and the drunken Fit holda longer than that produe'd by Wines, by reafon of its more vifcid Confiftence.

Hydromel is the common Drink of the Votes and Ruffians. Ttiodonis Siculus, lib. V. and Arijlotle, relate, that the Cel- tiberi and Tat/lantii, ancient People of Illyria, drank Hydro- mel inflead of Wine.

The Word is compos'd of S^, Water, and piu, Mef, Hone v.

HYDROMETER, an Inftrument wherewith to meafure the Gravity, Denfity, Velocity, Force, or other Property or Circumstance of Water. See Water.

That wherewith the ipecific Gravity of Water is deter- min'd, is more ufually call'd an Areometer or Water-pcife. See Areometer and W hruKpoife.

The Word is compounded of the Greek, $&,?, Water, and /tiT&v, Meafure.

HYDROMETRIA, Hydp.ometry, the Menfuration of Waters, and other fluid Bodies, their Gravity, Force, Ve- locity, Quantity, fgc. See Water and Fluid.

Hydrometrie includes both Hydroftai icks and Hydraulicks. See HydrostAticks and Hydr auligks.

The Term is modern, and very little in ufe. — The firft Inftance where we meet with it, is in the Year 1694, when a new Chair or Profefforfhip of Hydrometry was founded in the Univerfity of Boulogne, in Favour of S. Gtglislmini, who had carry'd rhe Doctrine of Running Waters, wiih re- flect to Rivers, Canals, Dikes, Bridges, £*?c to an unufual Length. See RrvER, Wave, &c.

HYDROMPHALUS, in Medicine, a Tumor in the Na- vel, arifing from a Collection of Water.

The Hydromphahts is diflinguifh'd from other Tumors of the Navel by its being very Sift, and yet not tractable or obedient to the Touch, fo as to diminifh or enlarge by com- preffing it. When view'd, piae'd between the Eye and the Light, it is found tranfparent.

"The Hydromphahts is difcufs'd by emollient and refolu- five Medicines, It is alfo alio cur'd by a Puncture made in the Middle of the Navel.

The Word is form'd of the Greek, "Jkf, Water, and e/«?£t*©-, umbilicus, Navel.

HYDROMTSTES, or Hydromysta, a Name given to certain Officers in the Greek Church, whofe Bufinefs was to make the holy Water, and fprinkle it on the People. See Holy Water.

The Word is compounded of '<%, aqua, Water, and (it/rtif, a Perfon fet apart for the Offices of Religion

HYDROPARASTATES, or Hydroparastes, a Seel of Hereticks, the Followers of Tatian, call'd alfo Encrct- tites, ApotaBites, Saccophori, Severiani, and Aquarians. See Encratites and Aquarians, ££?£.

The Hydroparajlates were a Branch of Manichees, whofe diftinguifhing Tenet was, that Water fhoutd be us'd in the Eucharift inflead of Wine.

The Word is form'd of the Greek, S&p, Water, and •melmpi, I prefent, I offer,

HYDROPHOBIA, in Medicine, an Averfion or Dread of Water; a Symptom arifing in Perfons bitten by a mad Dfg, or other Beaft.

Tho' the Term Hydrophobia do, in Strictnefs, only de- note this one Symptom; yet is it frequently apply'd to the whole Difeafe confequent on fuch Bite, with all its Symp- toms.

The Word is Greek, compounded of fiJiap, Water, and fog©-, Timor, Fear, of 003^/, timeo, I fear.

The Hiflory of this horrible Difeafe, as given bv CttlittS Aitrelitmas, Dr. Mead, Etmitller, Lifter, &c, is as follows :

\ The