way yet

If so be it that you haue an arche of suche greatnes, that your
squyre wyll not suffice therto, as the arche of a brydge or of a
house or window, then may you do this. Mete vnderneth the arch
where y^e midle of his cord wyl be, and ther set a mark. Then
take a long line with a plummet, and holde the line in suche a
place of the arch, that the plummet do hang iustely ouer the
middle of the corde, that you didde diuide before, and then the
line doth shewe you the middle of the arche.

[Illustration]

_Example._

The arch is A.D.B, of which I trye the midle thus. I draw a
corde from one syde to the other (as here is A.B,) which I
diuide in the middle in C. Then take I a line with a plummet
(that is D.E,) and so hold I the line that the plummet E, dooth
hange ouer C, And then I say that D. is the middle of the arche.
And to thentent that my plummet shall point the more iustely,
I doo make it sharpe at the nether ende, and so may I trust this
woorke for certaine.

THE XI. CONCLVSION.

When any line is appointed and without it a pricke, whereby
a parallel must be drawen howe you shall doo it.

Take the iuste measure beetwene the line and the pricke,
accordinge to which you shal open your compasse. Then pitch one
foote of your compasse at the one ende of the line, and with the
other foote draw a bowe line right ouer the pytche of the
compasse, lyke-wise doo at the other ende of the lyne, then draw
a line that shall touche the vttermoste edge of bothe those bowe
lines, and it will bee a true parallele to the fyrste lyne
appointed.

_Example._

[Illustration]

A.B, is the line vnto which I must draw an other gemow line,
which muste passe by the prick C, first I meate with my compasse
the smallest distance that is from C. to the line, and that is
C.F, wherfore staying the compasse at that distaunce, I seete
the one foote in A, and with the other foot I make a bowe lyne,
which is D, then like wise set I the one foote of the compasse in
B, and with the other I make the second bow line, which is E.
And then draw I a line, so that it toucheth the vttermost edge
of bothe these bowe lines, and that lyne passeth by the pricke
C, end is a gemowe line to A.B, as my sekyng was.

THE .XII. CONCLVSION.

To make a triangle of any .iij. lines, so that the lines be
suche, that any .ij. of them be longer then the thirde. For
this rule is generall, that any two sides of euerie triangle
taken toge