arche lines, whiche meete in C. and D, then drawe I a
lyne from C, so haue I my purpose.

This conlusion serueth for makyng of quadrates and squires,
beside many other commodities, howebeit it maye bee don more
readylye by this conclusion that foloweth nexte.

THE FIFT CONCLVSION.

To make a plumme line or any pricke that you will in any
right lyne appointed.

Open youre compas so that it be not wyder then from the pricke
appoynted in the line to the shortest ende of the line, but
rather shorter. Then sette the one foote of the compasse in the
first pricke appointed, and with the other fote marke ij. other
prickes, one of eche syde of that fyrste, afterwarde open your
compasse to the wydenes of those ij. new prickes, and draw from
them ij. arch lynes, as you did in the fyrst conclusion, for
making of a threlyke triangle. then if you do mark their
crossing, and from it drawe a line to your fyrste pricke, it
shall bee a iust plum lyne on that place.

[Illustration]

_Example._

The lyne is A.B. the prick on whiche I shoulde make the plumme
lyne, is C. then open I the compasse as wyde as A.C, and sette
one foot in C. and with the other doo I marke out C.A. and C.B,
then open I the compasse as wide as A.B, and make ij. arch lines
which do crosse in D, and so haue I doone.

Howe bee it, it happeneth so sommetymes, that the pricke on
whiche you would make the perpendicular or plum line, is so nere
the eand of your line, that you can not extende any notable
length from it to thone end of the line, and if so be it then
that you maie not drawe your line lenger from that end, then doth
this conclusion require a newe ayde, for the last deuise will
not serue. In suche case therfore shall you dooe thus: If your
line be of any notable length, deuide it into fiue partes. And
if it be not so long that it maie yelde fiue notable partes,
then make an other line at will, and parte it into fiue equall
portions: so that thre of those partes maie be found in your
line. Then open your compas as wide as thre of these fiue
measures be, and sette the one foote of the compas in the
pricke, where you would haue the plumme line to lighte (whiche I
call the first pricke,) and with the other foote drawe an arche
line righte ouer the pricke, as you can ayme it: then open youre
compas as wide as all fiue measures be, and set the one foote in
the fourth pricke, and with the other foote draw an other arch
line crosse the first, and