Page:Cyclopaedia, Chambers - Volume 1.djvu/536

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sic Performances, confifling of a few Scenes not divided Circle of Declination is a great Circle of ttia

into Acts, rehears'dby the StudenM by Way ofExercife, Sphere, pairing through the Poles ot the World : Such,

and to form them for Speaking in public. Such Decla- is PGDK, paffing through the Poles T and K.

mationstna the mod ufeful Exercifcs perform'd in the 'Parallax of the Declination is an Arch of the

Colleges. Circle of Declination, whereby the Parallax of the Al-i

DECL ORATION, in Law, a Shewing in Writing titude increafes or diminifhes the 'Declination of the

the Grief and Complaint of the Demandant, orPlaintiff, Star. See Parallax.

aeainft the Defendant, or Tenant, wherein he is fuppofed RefraBion of the Declination, an Arch of the

to have receiv'd fome wrong. This ought to be plain Circle of the Declination, whereby the Declir.

and certain, both becaufe it impeachcth the Defendant, and alfo compels him to anfwer thereto.

nation by means of tha

Declaration

alfo us'd for a Confeffion which

the Quakers, who fcruple taking the Oaths of Supre- macy ££r. are oblig'd to make and fubferibe in lieu there- of. Its Tenor is a folemn Promife before God and the

of a Star is increafed, or diminilh.

Refraction. See Refraction.

Declination of the Needle, or Compafs, is the

Variation from the true Meridian. See Variation

of the Needle.

Declination of a'Planc, or Wall, in Dialling, is an World, to be true to King George, with a Deteftation Arch of the Horizon, comprehended either between the and Horror of that damnable Pofition, that Princes, ex- Plane, and the Prime Vertical Circle, if you account itfrom communicated by the Pope, or any other Power, may be Eaft to Weft; or between the Meridian, and the Plane, if depofed or murther'd; and a Declaration, that no fo- you account it from the North, or South. SeeDECLiNEK. reignPrince, or Power, has any Right, Jurisdiction, or An- There are many Ways given by Authors for finding thority in this Kingdom. the Declination of Planes : The mod handy and

DECLENSION, in Grammar, an Inflexion of practical Way is by a Declinator. See Declinator. Nouns, according to their divers Cafes; as Nommathe, DECLINATOR, an Inflrument in Dialling, wherc- Genitive, &c. See Case, Nominative, &c. by the Declination, Inclination, and Reclination of

The Declenfion of Nouns is a different Thing in Planes is determined. Its Structure is as follows : the modern Languages, which have not properly any On a fquare wooden Board ABCD, ('Tab. Dialling Cafes 5 from what it is in the ancient Greek and La- Fig.i.) defcribe a Semi-Circle AED, and divide the two tin, which have. Quadrants thereof AE and ED into 90 Degrees, each

Declenfion, with Refpect to Languages, wherein beginning from E, as in the Figure. Then, having the Nouns admit of Changes, whether in the Beginning, fix d a Pin in the Center F, fit a wooden Ruler HI the Middle, or the Ending, is properly the Expreilion upon the fame, moveable thereon, with a Box and of all thofc Changes in a certain Order, and by cer- Needle K, as fhewn under Compass. tain Degrees, call'd Cafes : With Regard to Languages, Now, to apply this, in taking the Declination of wherein the Nouns do not admit of Changes in the a Plane, applying the Side AD of the Inftrument to fame Number, Declenfloti is the Expreilion of the the Plane purpofed, as MN'ivg. 2. and move the Ruler different States, or Habitudes a Noun is in, and the FG, with the Compafs G this Way and that, and about different Relations it has; which Difference of Re- the Center F, till the Needle reft upon the Line of

lations is mark'd by Particles, call'd Articles; as. the, of, to, from, &c.

Declension of a Difeafe, is when it is paft Height, and the Symptoms abate. See Acme.

the Magnetical Meridian of the Place. Now if the Ruler in this Situation cut the Quadrant in E, the Plane is either Northern or Southern : But if it cut between D and E, the Plane declines to the Weft; or, if be-

DECLINATION, "in Aftronomy, the Diftance of tween AE, to the Eaft by the Quantity of the Angle

the Sun, a Star, Planet, or other Point of the Sphere GFE.

of the World, from the Equator, either Northward, The fame Inftrument will ferve to take the Incli-

or Southward. See Equator. nations and Reclinations of Planes. To this End, in-

Declination is either real or apparent, according ftead of the Ruler and Needle, a Thread with a Plum- as the real or apparent Place of the Point is confider'd. met is fitted on a Pin in the Center E : Then the Side See Place. BC of the Declinator ABCD, being applied to the

Hence the Declrnation is an Arch of a great Cir- propofed Plane, as IL Fig. 3. If the Plumb-Line

cle, as GS, (Tab. Afironomy Fig. 4.) intercepted between PG cut the Semi-Circle AED in the Point E, the

a given Point, asS, and the Equator AQ., and perpen- Plane is Horizontal 5 Or if it cut the Quadrant EL

dicular to the fame. Confequently, the Circle, by in any Point as G, then will EFG be the Angle of

whofe Arch the Declination GS is meafured, paffes Inclination : Laftly, if applying the Side AB to the

through the Poles of the World. See Circle of Decli- Plane, the Plummet cut E, the Plane is Vertical.

nation. Hence, if the Quantity of the Angle of Inclina-

The Declination of a Star, 5?c. is found by firft tion be compared with the Elevation of the Pole,

obferving the Altitude of the Pole as PR, {Tab. Afro- and Equator; it is eafily known, whether the Plane

nomyFig.'j.) This fubftracted from jo». gives the Height be inclined, or reclined. See Inclination, and Re-

of the Equator AH. Then, the Meridian Altitude of the clination.

Star, HD being obferved, if it be greater than the Aid- DEC LINERS, or Declining Dials, are thofe which

tude of the Equator, AH, the : latter fubftracted frorn the cut either the p lane of tho ^ me v ' ettksi Cirde> or

former leaves iheDeclination Northward AD: Or, if the Altitude of the Star HT be lefs than that of the Equator HA, the former fubftracted from ths latter leaves theZte- Circl. clination Southward TA. e. g. Tycho at Vranisbour^ obferv'd the Meridian Altitude of the Cauda Leonis

HD Altitude of Equat. HA

Declinat. therefore, AD 16

5°' 34

the Plane of the Horizon obliquely. See Dial. If we conceive the Plane of the prime Vertical to revolve a little upon a right Line drawn from Zenith to Nadir; The Plane will become de- clining; nor will it be any longer cut at right Angles by the Meridian, but by fome' Vertical Circle paffing through the intermediate Points. After the like Man- ner a Horizontal Plane will be brought to decline, if If the Star be in the Quadrant ZR, then the lead revolving on the Meridian Line, one Part of it be Altitude MR fubftracted from the Altitude of the Pole raifed a little towards the Zenith, and the other de- PR, leaves the Diftance from the P«Ie PM; which prefs'd towards the Nadir.

fubftracted again from the Quadrant PQ, leave the The Ufe of Declining Vertical Dials is very frequent, ^Declination MQ. e. g. M. Coiiplet obferved PM m Regard the Walls of Houfes, whereon Dials are 2" 18' 50" which fubftracted from 00° leaves MQ. ™ m f™ 1 >' drawn. do generally decline from the Car- Si" 41' 10". And by this Method are conftruaed £"• <■ lndmeis and Rimers, and efpecially the Tables of Declinations of the fix'd Stars given I)eindlner5 > are very rare. See Dial.

5? o

5 20

53 4°-

DECLINING,

us by Ricciolus and Dechales.

By comparing the ancient Obfervations with the mo- dern, it appears, that the Declination of the fix'd Stars is variable; and that, differently, in different Stars.

for in fome it inweafes, and in others decreafes, and that call'd alfo Ob'liquus Defcendens. in different Quantities. The greatett Increafe or Decreafe fcendens.

DECLIVITY. See Aclivity.

Ercfl, ->

Inclining, >Dials. See Dial. Reclining 3 DECLIVIS, in Anatomy, a Mufcle of the Abdomen, See Obliojjos De-

doth not exceed three Minutes and a half in 10 lears Time.

It has been greatly difputed among the latter Ma- thematicians, whether or no the Declination and Ob- Jiquity of the Ecliptic be variable; but the Point feems now decided in Favour of the Immutability. See Obli- quity, and Eciutick.

DECOCTION, the Ait of Boiling one, or more Plants, or other Drugs, to extract die Juice out of the fame for fome medicinal Purpofe.

De coitions of Guaiac, and Sarfaparilla, are the com- mon Drink in certain Difeafes. See Apozem, and Infusion.

Mon r r-