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HeIchts, in the military Art, are the Eminences round a fortified Place, whereon the Armies ufually pofl themfelves. — The Enemy had fciz'd all the Heights : Ap- peared on the Heights, &c.

HEIR, Hares, in the Civil Law, he who fucceeds to the whole Eitate and Effects of another, whether by Right of Blood, or of Teftamenr. See Succession.

The Inftitution of an Heir, is a Grcumilance neceffary to the Validity of a Teftamcnt. See Testament.

There are two principal Kinds of Heirs, Apparent and tPrefumptive.

An Heir Apparent, is he on whom the Succcffion is fo fettled, that he cannot be fet afide, without altering the Laws of Succcffion.

Heir Prefumpthe, See Presumptive Heir.

The Word is form'd of the Latin Hares, of the Verb hcerere, to flick, remain fail, be near, follow immediately, &c.

Heir, in Common Law, is he who fucceeds, by Right of Blood, to any Man's Lands, or Tenements in Fee.

for, nothing paflcs in Common Law, Jure hareditatis, by Right of Inheritance, but Fee. Sec Fee.

By Common Law, therefore, a Man cannot be Heir to Gootis or Chattels; for Hares dicttur ab hareditate: 'Tis the Inheritance denominates the Heir. See Inheritance.

Every Heir, having Lands by Defcent, is bound by the Acts of his Anccftors, if he be named j it being a Maxim, that qui fentit Commodum [entire debet £5" Onus.

Moveables, cr Chattels immoveable, are given by Tefta- menr, to whom the Teftator thinkcth fit; otherwife they lye at the Diffofirion of the Ordinary, to be diftributed as he in Confcience likes belt.

Laf Heir, See Last Heir.

Heir Loom, in our Law-Books, fignify fuch Houfhold Furniture, as is not inventoried after the Owner's Dcceafc; but neceffarily comes to the Heir along with thcHoufe. Sec Heir.

Heir Loom comprehends divers Implements $. as Tables, Prcffes, Cup-boards, Bed-fteads, Furnaces, Wainfcot, and fuch like, which, in fomc Countries, have belonged to a Houfe for certain Defcents, and arc never inventoried after the Deceafe of the Owner as Chattels are, but accrue by Cuftom, not by common Law, to the Heir, with the Houfe it felf

Confuetudo Hiindredi de Stretford, in Com. Oxon. eft quod haredes tenementorum infra, Hundredum preditJ. ex fen. pofi- mortem Antecefforum fuorum habebunt, &c. t Principalium, Anglice an Heir-Loome, viz. 2Je quodam genere Catallorum, titenfilium, &c. Optimum pU uftrum, cftimam Caritcam, optimum Ciphum, &c. Coke on Littleton.

HELCESAITES, or Elcesaites, a Sect of antient Hereticks, in the lid Century; denominated from their Leader Elxai, or Helxeus.

The Helcefitites condemn'd Virginity, and held it a Duty of Religion to marry : They taught that Jefus Chrift was a mere Creature, who appear'd at the Begin- ning of the World in the Figure of Adam, and afterwards under that of Jefus Chrift. That the Holy Spirit, which they fuppofed of the Female Sex, was the Sifter of Jcfus, ££c. They cftablifTi'd feven Witncrles of an Oath, viz. Salt, Water, Earth, Bread, Heaven, Air and the Wind,

HELEPOLIS, in Antiquity, a military Machine, for the battering down the Walls of a Place befieged.

The Helepolis, as defcribed by 2)iod. Siculus, &c. ap- pears to have been no more than the Aries, or battering Ram, with a Roof, or Covering over it, to prevent its being fet en Fire, as alfn to fcreen the Men who work'd it. See Aries.

Some will have it a Combination of two or three bat- tering Rams, moving on large flrong Wheels, roofed over, and cover'd with raw or wet Skins. It had feveral Iron Points, or Heads, wherewith the Execution was done $ form'd much like the Thunderbolts which Painters reprefent. Within, was a great Number of Soldiers, who drove it with Force of Arm and by Means of Ropes, violently againft the Wall where the Breach was intended.

Others, will have Helepolis a generical Name, comprehend- ing all the Machines ufed by the Antients in the befieoing of Towns; as, among us, the Name Artillery includes all the Sorts of Fire Arms. —But this Opinion is chiefly founded on the Origin of the Name, and does by no Means fuit with thofe minute Descriptions given of the Helepolis in the antient Writers.

The Word is Greek, foimUfj compounded of the Words JA&V, to take j and WA/f, City.

The Invention of the Helepolis, and divers other mili- tary Machines, is afcribed to IDemetrius, which, with the great Number of Cities he took thereby, gave him the Denomination of Poliorcetes, or City Taker.

HELIACA, in Antiquity, Sacrifices, and other Solem- nitits, perform'd in Honour of the Sun $ whom the Greeks call Helios, &i©-. See Sun, Circus, iSc.

HELIACAL, in Aftronomy. — The Heliacal Rifing of a Star, Planet, &c. is its iffring. or emerging out of

the Rays anal Luflre of the Sun, wherein it was before hid j whether this be owing to the Recefs of the Sun from the Star, or of the Star from the Sun. See Rising.

Heliacal Settling, is its entering or immerging into the Sun's Rays, and fo becoming inconfpicuous t>y the fu- perior Light of that Luminary. Sec Setting.

Or, a Star rifes Heliacally, when after it has been in Conjunction with the Sun, and on that Account invisible, it gets at fuch a Diltance from him, as to be feen in the Morning before the Sun's Riling. — ■ The fame is faid to fet Heliacally^ when it approaches fo near the Sun, as to be hid therein. So that, in Stri&nefs, the Heliacal Rifing and Setting, are only an Apparition and Occupation, See Occultation, &c.

The Heliacal Rifing of the Moon, happens when /lie arrives at the Diftance of 17 Degrees from the Sun; for the other Planets, 20 Degrees Diftance is required : And for the Stars more or lefs, as they are greater or fmallcr. See Moon, Planet and Star.

To find the Heliacal Rifing and Setting by the Globe. See Globe.

The Antients computed that a Star, between the Tro- picks, would be forty Days ere it got clear of the Sun's Rays, and become confpicuous again. Hejiod firft made this Computation 5 and the reft follow'd him. The Period comes very near to the Computation of the Moderns : For the Sun advancing nearly a Degree every Day, it will be 20 Days approaching thereto, from the Heliacal Setting of the Star 5 and 30 Days more withdrawing, till the He- liacal Rifing.

The Word is derived from the Greek, £**©-, Sol, Sun.

HELIASTES, in Antiquity, Officers, or Magiftrates of Athens, constituting a Court of 500 Perfons, or Judges, who took Cognizance of Civil Matters.

The Court of Heliafes was one of the fix Civil Juris- dictions of Athens 5 and that to which Matters of the greateft Moment were ufually brought : So that it was held rhe raoft confiderabJe of all the Civil Tribunals. The Delinquencies of the military Men were alfo brought before the Heliafes.

Ulpian gives us two Etymologies of the Word : Some, fays he, derive it from «a*©-, Helios, Sun $ and hold it thus call'd by Reafon they fat in the open Air, in Sight of the Sun. Ulpian himfelf chufes rather to derive Heliafes from 'H\ia.U, Heliaa, the Place where this Court, or Council was held; and that from <i\ify 3 / affemble, of aha, fatis, enough.

HELlCE, in Aftronomy, the fame with Urfa. See Ursa.

HELICOID Parabola, or the (parabolic Spiral, a Curve ariling upon a Supposition of the Axis of the com- mon Apollonian Parabola's, being bent round into the Periphery of a Circle. See Parabola.

The Helicoid Parabola, then, is a Line paffing thro* the Extremities of the Ordinate, which now converge to- wards the Centre of the faid Circle.

Suppofe, e.gr. the Axis of the common Parabola to be bent into the Periphery of the Circle BDM, Tab. Conicks Fig. 11 j then, the Curve B F G N A, which paffes thro' the Extremities of the Ordinates CF, and D G, which converge towards the Centre of the Circle A; conftitutes what we call the Helicoid, or Spiral Parabola.

If the Arch B C, as an AbfcifTc, be called x, and the Part C F of the Radius, as an Ordinate to it, be call'd y $ the Nature of this Curve will be exprefs'd by the Equa- tion lx=yy. See Curve and Equation.

HELIOCENTRIC, in Aftronomy, is applied to Things which would appear fo to the Eye, were it placed in the Centre of the Sun. See Sun.

The Word is compounded of n\i®- } Sun, and vmt^v. Centrum.

Heliocentric Latitude of a Planet, is the Inclination of the Line drawn between the Centre of the Sun and the Centre of a Planet, to the Plane of the Ecliptic. See Latitude.

The Heliocentric Latitude of a Planet is thus determined. — ■ If the Circle K L M, Tab. Afronom. Fig. 62. reprefent the Orbit of the Earth round the Sun, and the inner one A N B n be placed fo, as to be inclined to the Plane of the other (for which Reafon it appears in the Form of an Ellipfis) when the Planet is in N or n, (which Points are called its Nodes) it will appear in the Exliptic, and fo have no Latitude 5 if it move to P, then, being feen by the Sun, it will appear to decline from the Ecliptic, or to have Latitude $ and the Inclination of the Line R P, to the Plane of the Ecliptic, is called the Planet's Heliocejitric Latitude, and the Meafure of it is the Angle P R q, fuppofing the Line P q, to be perpendicular to the Plane of the Ecliptic.

This Heliocentric Latitude will be continually increafing, till it come to the Point A, which they call the Limit, or utmoit Extent of it; and then it will d^crgafe again,