Page:The Mathematical Principles of Natural Philosophy - 1729 - Volume 1.djvu/56

 12 are wift or low, or none at all: and therefore it ought to be ditinguih'd from what are only enible meaures thereof; and out of which we collect it, by means of the Atronomical equation. The neceity of which Equation, for determining the Times of a phænomenon, is evinc'd as well from the experiments of the pendulum clock, as by eclipes of the Satellites of Jupiter.

As the order of the parts of Time is immutable, o alo is the order of the parts of Space. Suppoe thoe parts to be mov'd out of their places, and they will be moved (if the expreion may be allowed) out of themelves. For times and paces are, as it were, the Places as well of themelves as of all other things. All things are placed in Time as to order of Succeion; and in Space as to order of Situation. It is from their eence or nature that they are Places; and that the primary places of things hould be moveable, is aburd. Thee are therefore the abolute places; and tranlations out of thoe places, are the only Abolute Motions.

But becaue the parts of Space cannot be een, or ditinguihed from one another by our Senes, therefore in their tead we ue enible meaures of them. For from the poitions and ditances of things from any body conider'd as immovable, we define all places: and then with repect to uch places, we etimate all motions, conidering bodies as tranfer'd from ome of thoe places into others. And o intead of abolute places and motions, we ue relative ones; and that without any inconvenience in common affairs: but in Philoophical diquiitions, we ought to abtract from our enes, and conider things themelves, ditinct from what are only enible meaures of them. For it may be that there is no body really at ret, to which the places and motions of others may be referr'd. Rh

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