Page:Cyclopaedia, Chambers - Volume 2.djvu/78

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We have already obferved that the Altitude of the Pole is always equal to the Latitude, for which Reafon the la- titude might be beft found by obferving the Pole's Height : But in regard the Pole is only a mathematical Point, and no ways 10 be obferved by our Senfes, its Height cannot be determined in the fame manner as that of the Sun and Stars, ££re. for which Reafon another Manner has been con- trived. In order to this, a Meridian Line is fir ft drawn j the Method of doing which, fee under rhe Word Meridian. Place your Quadrant on this Line, fo as its Plane may be in the Plane of the Aleridians then take fome Star near the Pole, v. g. the Pole Star, which never fets, and ob- ferve both its greateft and leaft Altitude (fee Quadrant.') Let the greateft, v. e. be SO, (Fig. 5. Plat. Geography) and the leall sO b the Half of which PS or V s, de- dueled from the greateft Altitude S O, or added to the leaft iO will give P O, the Altitude of the Pole above the Horizon, which is equal to the Latitude of the Place.

The Latitude may alfo be found, by having the Sun's, or a Star's Declination, and Meridian Altitude taken with a Quadrant or Aftrolabe. The Method is this: Obferve the Meridian Diftance of the Sun from the Vertex or Zenith, which is always the Comple- ment of hi* Meridian Altitude j and add to this the Sun's Declination, when the Sun and the Place are on the fame Side the Equator, or fubftract the Declination when they are on different Sides : the Sum in the former Cafe, and the Difference in the latter, will be the Latitude required. But when the Declination of the Sun is greater than the Latitude of the Place, which is known from the Sun's being nearer to the elevated Pole than the Vertex of the Place is, as it frequently happens in the Torrid Zone ; then the Difference between the Sun's Declination, and his Zenith Diftance, is the Latitude of the Place. If the Sun, or Star, have no Declination, but move in the Equinoctial that Day 5 then the Elevation of the Equator will be equal to his Meridian Altitude, and confequently his Meridian Altitude is the Complement of the Latitude to 90. This latter Method is belt accommodated to the Ufes of Na- vigation, as being practicable at Sea : but the former Me- thod preferable at Land.

Latitude, in Aftronomy, is the Diftance of a Star or Planet from the Ecliptic, or from rhe Sun's Orbit, to- wards one of the Poles of the Zodiac. Through the Poles of the Ecliptic are fuppofed to pafs an indefinite Number of great Circles, cutting the Ecliptic at Right Angles, called Circles of Latitude, or Secundaries of the Ecliptic ; By means of which, every Star and Point of the Heavens is reduced to the Ecliptic, and has its Place in regard thereto determined. The Latitude of a Star is an Arch of one of thefe Secundaries, intercepted between that Star and the Point where it interfedts the Ecliptic 5 in which jt differs from the Declination, which is the Diftance of a Star from the Equator towards one of the Poles of the World: So that the Geographical Latitude is the fame thing with the Agronomical Declination, and the Aftrono- inical Latitude a quite different thing. The Sun never has any Latitude, but the Planets have : For which reafon, in the common Sphere the Zodiac has fome Breadth. The Antients only allow'd fix Degrees on each Side the Eclip- tic, but the Moderns have extended it to nine. According to the Obfervation of fome of the modern Aftronomers, the greateft Latitude of the Planets is not always the fame; but V'enus never exceeds 9 Degrees Northern Latitude, Mer- cury 5 Degrees, the Moon in her Quadrant with the Sun 5 Degrees; Saturn z Degrees, 50 Minutes 5 Jupiter 1 De- gree, 50 Minutes; Mars 7 Degrees, 31 Minutes. When they have no Latitude, they are faid to be in the Nodes of the Ecliptic, or in the Interferon of their Orbit with that of the Sun j and in this Situation it is that they eclipfe, or are eclipfed by the Sun.

North Afcending Latitude is when the Moon pro- ceeds from the Afcending Node towards her Northern Limit, or greateft Elongation ; North Defcending La- titude, when the Moon returns from her Northern Li- mit to the Afcending Node : South Defcending Lati- tude, is when Jhe proceeds from the Defcending Node to her Southern Limit ■■> South Afcending Latitude, is when me returns from her Southern Limit to her Afcending Node: And the fame holds good of the other Planets. Heliocentric Latitude of a Planet, is its Diftance from the Ecliptic, fuch as it is feen from the Sun ; and this, when the Planet comes to the fame Point of its Orbit, is always the fame, and unchangeable. Geocen- tric Latitude of a Planet, is the Diftance of the Planet from the Ecliptic, as it is feen from the Earth : And this, though the Planet be in the fame Point of its Orbit yet is not conftantly the fame, but alters according to the Pofition of the Earth, in refpeft to the Planet. See Heli- ocentric and Geocentric.

Dr. Bailey has fome Confiderations in the Philosophical TranfaBions, which make it probable the Latitudes of fome

of the principal fix'd Stars, particularly Palilidum, Shitts, and JrSlurus, alter in time j whence ir may be argued, the reft likewife alter, tho' the Variation may be lefs conspi- cuous in thefe, by reafon they are fuppofed at a greater Diftance from us. See Star.

LAT1TUDINARIAN, among the Divines, fignifies a moderate Perfon, not over-clofely tied to any religious Opinions, but thinks there is a Breadth or Latitude in the Road to Heaven.

LATOMI A properly fignifies a Quarry, or Place whence Stones are dug. Thefe were antiently ufed as Goals for Criminals. 'Pionyfius had a Place of this kind dug in a Rock near Syracuje, where an infinite Number of People were fhut up. Cicero reproaches Penes with imprifoning Roman Citizens in Latomias ; fo that Latomia became a general Name for a Prifon, and the Prifoners inclofed in 'em, were called Laatomarii. The Word comes from the Greek htts Stone, and rifwa I cur.

LATRIA, in Theology, is a religious Wor/hip due only to God. The Komanijis fay they honour God with the Wor/hip of Latria, and the Saints with the Worfhip of Vulia. But thefe Terms, however diftin<3, are ufually confounded. This Worihip of Latria, befides its inner Characters, has its external Marks to diftingui/h it 5 the principal whereof is Sacrifice, which cannot be offered to any other but God himfelf, as being a folemn Acknow- ledgment or Recognition of the Sovereignty of God, and our Dependance on him. Mr. DaiUe feems to own that fome of the Fathers of the fourth Century allowed the Diftinclion between Latria and Dulia. The Word comes from the Latin latere, to lie hid. See Idolatry.

LATUS RECTUM, a Term in Conicks, the fame with Parameter 5 which fee.

LATUS TRANSVERSUM of the Hyperbola, is a Right Line intercepted between the Vertices of the two oppoiite Sections 5 or that part of the common Axis which is between theVertices of the upper and lower Cone, as the Line E D (in Fig. 5. Flat. Conicks) where alfo D d and E e may be the Parameters, orLatus Reclums belonging to the two oppofue Sections G L R O, and O E O R. To this Lotus Tranfverfum anfwers the longeft Diameter in the Ellipfis 5 which Afollonius calls the tranfverfe Axis or Dia- meter. Latus Primarium is a Right Line belonging to a Co- nick Seclion drawn thro' the Vertex of the Section of the Cone, and within it, as the Line E E or D D in the Figure above referr'd to.

LAVATORY, or LAVADERO, a Name given to certain Places in Chili and Peru, where Gold is got out of Earth by waffling. M. Frezer gives us the following Defcription of the Lavatories of Chili: They dig deep into the Earth, in fuch Places as they have reafon to ex- pe£f Gold in 5 and in order to facilitate this Digging, turn a Stream of Water upon the Spot, loofening the Earth as much as poflible all the time, that the Cur- rent may have the greater Effecl, and tear up the Earth more ftrongly. When they are got to the Earth they want, they turn off the Stream, and dig dry. The Earth that they, now, get is carried on Mules, and difcharged in- to a Bafon, made fomewhat in the manner of a Smith's Bellows, into which a little Rivulet of Water runs with a great deal of Rapidity, diffolving the Partsof the Earth, and carrying every thing away with it excepting the Par- ticles of Gold, which by their great Weight precipitate to the Bottom of the Bafon, and mix with a fine black Sand, where the fmaller Parts are almoft as much hid- den as before they were in the Earth. Sometimes they find very considerable Pieces in Lavatories, particular- ly Pieces of twenty-four Ounces each. There are fe- veral Lavatories, where they find Pefitas, or Grains of Virgin Gold, of a prodigious Size. Among others they tell of one that weighed 512 Ounces, bought by the Count de la Moncloa, Viceroy of Peru. Nine or ten Leagues to the Eaji of Coquimbo, are the Lavatories of Anda- coll, the Gold whereof is twenty-three Carats fine. Their Work, here, always turns to great Profit, excepting when the Water fails them. The Natives maintain that the Earth is creadice, rhat is, it produces Gold continually j becaufeafter having been waftied flxty or eighty Years, they find it impregnated afrefh,and draw almoft as much out of it as at firft.

LAUDANUM, a Name given by the Chymifts to certain Preparations of Opium, by reafon of their excel- lent Qualities, as who fhould fay laudandum from laudare, to praije. To thefe feveral add Coral, Pearls, Treacle, £5?c. Laudanum is efteemed an excellent Medicine, it af- fuages Pain, flops the fpitting of Blood, the Flux of the Menfes and Hemorrhoides, &c.

LAUDS, or LAUDES, the fecond Part of the ordi- nary Office of the Breviary, faid after Matins, though heretofore it ended the Office of rhe Night. The Laudes confift principally of Pfalms, Hymns, &c. whence they took their Name. StcMatins and Breviary.

LAUGH-