Page:Cyclopaedia, Chambers - Volume 2.djvu/235

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all fUperfluous Moifiure. Or, it may be prevented, in the fcrfl planting of Trees, by not fetting them too deep.

MOTE,Mota, of the Saxon, Gemote; a Term fre- quently occurring in our antient Cuftoms, literally denoting a Meeting, Coutt, or flea.

Of Motes, or Gemotes, confider'd in theSenfe of Affem- blies, ot Courts, there were divets kinds, as Witbenagemote, Tolkegetnote, Schiregemote, Hundredgemote, Burgemoie, Warde- getnote, Haligcmotc, Sujainegemote, &c. See each under its proper Article, Witiien agemote, Fqlkegemote, i$c.

Mote, Mota, was alio ufed for a Fortrefs, or Callle ; or the Scite or Mace where fuch Callle flood : As Mota de Windfor, SSc

Mote was alfo a (landing Water to keep Fifh ; or a large Ditch incompaflingaCaftle, or Dwelling-Houfe. See Moat.

MOTHER, Mate<; a Female who (lands in the Relation of Parent toanother. See Parent, G?c.

Thus £« is call'd our common Mother. Cybcle among the Antierits wa&the Mother of the Gods.

The Queen Mother is the fame with what we otherwife call Queen Dowager, See Dowager.

We meet with Emptcffcs on Medals and Infcriptions with the Titles of Mother of the Camp ; Mother of the Senate, Mother of the Country : Mater Senatus, Mater PatrU\ l£c. See Father.

Mother Tongue, is properly an original Language, from which others are apparently fnrm'd. See Language.

Of Mother Tongues, Scaliger reckons ten in Europe, iitz. the Greek, Lathi, Teutonic or German, Sclavonic, Epirotic, Scy- thian or European Tartar, Hungarian, Cantabrian, IriJIi, and hritifi. See Greek, Latin, Teutonic, ££?<•.

MoTHERCAarctej are thofe which have founded or e- recfed others. See Church.

In Beneficiary Matters we fay it is not lawful for a Man to enjoy at the fame time both the Mflber and the Daugh- ter : Meaning that the Canon Law does not allow an Abby, and the Benefices depending theteon, to be held by the fame Perfon.

Mother of Pearl, fee Pearl.

Ttis.of the MofHEK, fee Hysteric JffeBion.

MOTION, primarily fo call'd, or Local Motion, is a continued, and fucceffive Change of Place ; or that State of a Body whereby it correfponds fucceffively to feveral different Places, or is prefent fucceffively in feveral Parts of Space. See Place.

In this fenfe, the Docfrine and Laws of Motion make the Subject of Mechanics, ox Statics. See Mechanics, fife.

The antient Philofophers confider'd Motion in a more general and extenfive Senfe. They defined it by a Paffage out of one State into another ; and thus made fix Kinds, viz. Creation, Generation, Corruption, Augmentation, Diminu- tion, and Lation, ot Local Motion. See Creation, Ge- neration, ££c.

Some of the later Schoolmen reduce thefe fix Kinds of Motion to four : The firft is general, including any Paffage from one State to another j under which fenfe of Motion come Creation, ProduHion, and Mutation. The fe- cond is a Paffage of fomething already exiiling from one State to another; and thus Generation is a Motion. The third, a fucceffive Paffage of fomething already exiiling from one Term to another ; and thus Alteration ind Accre- tion ate Species of Motion. The lad, is Lation, or Local Motion j and thus Walking isMotion.

But the latell Philofophers unanimoufly deny any other Motion befide Local Motion ; and reduce all the Species above-mentioned to this one : So that we have here only to do with Local Motion t, whereof the reft are only fo many different Determinations, or Effects. See Accre- tion, Alteration, Generation, &c.

Phyfical Writers, both Antient and Modern, have ever been perplexed about the Nature and Definition of Local Motion.

The Peripatetics define it by ArJus Entis in potentia, prout hi potentia, Arid. 3. Phyf. c. 2. But the Notion is too Abilracf and Meraphyfical for our Days ; and is of no ufe in explaining the Properties of Motion.

The Epicureans call it the Migration of a Body, or a part of a Body, from one Place to another. On which Definition, the later Epicureans refine, and call it the Mi- gration or Paffage ol a Body from Space to Space : Thus fubftituting the word Space for that of Place. ■ The Cartefians define Motion •: Paffage, or Removal of one Part of Matter out of the Neighbouthood of thefe Parts immediately contiguous thereto, into the Neigh- bourhood of others.

Which Definition agrees, in effect, with that of the Epi- cureans ; all the Difference between 'em confiding in this, that what the one calls Body and Place ; the other calls Matter, and contiguous Parts.

Horelli, and other late Writers after him, define Motion more accurately and fully, the fucceffive Paffage of a

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Body from one Place to another, in a determinate time, by being fucceffively contiguous to all the Parts of the inter- mediate Space.

Motion, then, they agre^ to be the translation of a EoJy from Place to Place : Hut they differ infinitely when they come to explain wherein this Franjlation confifls. And hence their Diviiions of Motion become exceedingly pre- carious.

Jrijlotle, and the Feripatct'tcsy divide all Motion intoNti- tural and Violent.

Natural Motion is that which has its Principle, or mo- ving Force, within the moving Body. Such is that of a Stone falling towards the Centre ot tha Earth.

Violent Motion is that whofe Principle is without, and again!! which the moving Body makes a Refiftance : Such is that of a Stone thrown upwards.

The Moderns generally divide Motion into Abfolute and Relative.

Abjolute Motion is the Change of Place, in any moving Body ; whofe Celerity, therefore, will be meafured by the Quantity of the abfolute Space which the moveable Body runs thro'.

Relative Motion is a Mutation of the Relative, or vul- gar Place of the moving Body ■, and has its Celerity ac- counted by the Quantity oi' relative Space run thro'.

Others divide Motiojz into Proper, and Improper or Fo- reign*

Proper Motion is a removal out of one proper Place into another, wiiich hereby becomes proper, as being pof- feffed by this Body alone j in exclufion of all others : Such is the Motion of a Wheel in a Clock.

Improper, or Extraneous, or Foreign, or Common Motion, is the Paffage of a Body out of one common Place into another common Place ; Such is that of a Clock when moved in a Ship,^c.

The Reafon of all this Diverfity feems to arife from the not attending to the different Meanings of the Words 5 but comprizing all in one Definition and Diftintlion ; which they fhould rather have dillinguiJh'd into feveral parts.

Some, e.g. in their Definitions of Motions, confider the moving Body, not as it regards the adjacent Bodies, but as it regards immoveable and infinite Space. Other?, again, confider the moving Body, not as it regards infinite Space but as it regards other Bodies vaftly remote. And others lafily, confider the moving Body, not as it regards remote Bodies, but that Surface only to which if is contiguous

But thefe various Meanings once fettled, the Difpute clears up 5 for as every thing that moves may be confider'd in thefe three feveral Manners ; there hence arife three feveral kinds of Motions $ whereof that which regards the Parts of infinite immoveable Space, without consideration of the circumambient Bodies, may be call'd abfolutely and truly proper Motion. That which regards circumambient Bodies vaftly remote, which may themfelves poffibly be moved, we call relatively common Motion. The laft, which regards the Sutfaces of the next contiguous Bodies, in as much as it may want all both abfolute and common Mo- tion, we call relatively proper Motion.

1. An abfolutely and truly proper Motion then, is the Ap- plication of a Body to different Parts of infinite and im- moveable Space. This alone is proper and abfolute Motion, being always generated and changed by Forces imprefj'd on the moving Body itfelf, and by thofe only; and being that to which the real Forces of all Bodies to put others in Motion by impulfe, are owing j and to which thofe Motions are proportioned. But this Motion we cannot inveftigateor determine accurately 5 nor can we diltingui/h, when two Bodies are impell'd on each other, in which of the two, v. g. that which appears to move the more fwiftly, or the other which appears to move more flowly, and perhaps even to be at reft, the real Motion, and, confequently, the real Force whence the lmpulie arofe, is placed j nor being able to determine whether the Centre of Gravity, or of the whole Syfiem (which is but a Point in infinite SpaceJ is itfelf at reft or in Motion.

%. Relatively common Motion is a Change of the Si- tuation of a Body with refpeel to other remote circum- ambient Bodies 5 and this is the Motion we fpeak of, when we fay that Men, Cities, and the Earth itfelf moves round the Sun. This is alfo the Motion we mean, when weeftimate the Quantity of Motion, and the Force any Body has to impel another: For inftance, if a wooden Sphere, fill'dwith Lead to make it the heavier, be caftfrom the Hand we ufe to eftimate the Quantity of Motion, and the Force which the Sphere has to^impel another, from the Celerity of the Sphere and thef'^Weight of the included Lead 5 and that truly with regard fo the Force itfelf, and the Effe& thereof as it falls under our Senfes ; But whe- ther the real Power or Motion be in the Sphere which ap- pears to ftrike, or in the Earth which appears to be ftruck, that, as has been obferved above, we cannot de- termine.

Laftly,