nd that is,
when a pricke standeth in the middell of a circle (as no circle
can be made by compasse without it) then is it called _a centre_.
[Sidenote: A centre] And thereof doe masons, and other worke
menne call that patron, a _centre_, whereby thei drawe the
lines, for iust hewyng of stones for arches, vaultes, and
chimneies, because the chefe vse of that patron is wrought by
findyng that pricke or centre, from whiche all the lynes are
drawen, as in the thirde booke it doeth appere.

Lynes make diuerse figures also, though properly thei maie not
be called figures, as I said before (vnles the lines do close)
but onely for easie maner of teachyng, all shall be called
figures, that the eye can discerne, of whiche this is one, when
one line lyeth flatte (whiche is named [Sidenote: A ground
line.] the _ground line_) and an other commeth downe on it, and
is called [Sidenote: A perpendicular.] [Sidenote: A plume lyne.]
a _perpendiculer_ or _plumme lyne_, as in this example you may
see. where .A.B. is the grounde line, and C.D. the plumbe line.

[Illustration]

And like waies in this figure there are three lines, the grounde
lyne whiche is A.B. the plumme line that is A.C. and the _bias
line_, whiche goeth from the one of them to the other, and lieth
against the right corner in such a figure whiche is here .C.B.

[Illustration]

But consideryng that I shall haue occasion to declare sundry
figures anon, I will first shew some certaine varietees of lines
that close no figures, but are bare lynes, and of the other
lines will I make mencion in the description of the figures.

[Illustration: tortuouse paralleles.]

[Sidenote: Parallelys]

[Sidenote: Gemowe lynes.]

_Paralleles_, or _gemowe lynes_ be suche lines as be drawen
foorth still in one distaunce, and are no nerer in one place
then in an other, for and if they be nerer at one ende then at
the other, then are they no paralleles, but maie bee called
_bought lynes_, and loe here exaumples of them bothe.

[Illustration: parallelis.]

[Illustration: bought lines]

[Illustration: parallelis: circular. Concentrikes.]

I haue added also _paralleles tortuouse_, whiche bowe contrarie
waies with their two endes: and _paralleles circular_, whiche be
lyke vnperfecte compasses: for if they bee whole circles,
[Sidenote: Concentrikes] then are they called _concentrikes_,
that is to saie, circles drawen on one centre.

Here might I note the error of good _A