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CHAP. IX.
Quantitie is that which comprehendeth the greatnesse and number or multitude of things, and is diuided into two kindes, that is, whole and broken.
Whole quantitie, called in Latine, quantitas continua, is that whose parts are ioined together with some common bound or limit, which is the ending of one part, and the beginning of ano∣ther, as the parts of the line here set downe in the margent, mar∣ked with the letters a. c. are coupled together with the middle* 1.1 point b. which point is the ending of a. b. and the beginning of b. c.
Of whole quantitie there be three kindes, that is, linea, superfi∣cies, and corpus.
Linea (in English, a line) is a length without either bredth or thicknesse, which is either right, or crooked; •…•…ight, as a yard, an ell, or pole; crooked, as a hoope, or circle.
Superficies (which wee may properly interprete to be the vp∣per face of any thing) is a length and bredth without depth or thicknesse; and that is either plaine, or bowing; plaine, as a plaine or smooth floore; bowing or compassing, as a vault or ouen, whereof the outward side is called conu•…•…x, and the inward side concaue or hollow.
Corpus (which is as much to say as a body) is that which hath both length, bredth, and depth, and that is either round, or with angles; round, as a bowle or ball; with a•…•…gles or co•…•…ners, as a square die, or such like thing. All which three kindes of quantitie are to be considered onely with the minde mathematically. as things abstract, and separated from all k•…•…nde of matter, t•…•…at is to say as things that haue no being •…•…t al, but imaginatiuely▪ and yet so nec•…•…ssarily inuented by man, as nothing can be measured with∣out