10. We come now to Joynery, which is an Art Manual, whereby several pieces of Wood are so fitted and joined together by straight lines, squares, Miters, or any Bevile Line, that they do seem one intire piece.
CXXXI. He beareth Sable, a semi-circle, with its Line and Plummet set upon a Standard, Or. This is an Instrument by which true Levels are takes, as also Heights and Distances; the semi-circle is generally made of Brass, being divided into 90 equal parts from the line of Level, to each side where the sight holes are fixed. The Standard is made of Wood, being three feet, which are so framed in the head, that they may be set wider or closer together, according as the place requireth.
CXXXII. In the chief, or front of this square, is placed one of the Joyners working Plains, called a Plow, which is a narrow Rabbet-Plain with some additions to it, viz. two square staves, let stiff through two square Mortesses in the Stock, which are about 7 or 8 inches long, and stand straight and square on the further side of the Stock, which have shoulders on the out-side of the Stock reaching down to the Wooden sole of the Plain, to the Wooden sole there is added an Iron sole of the thickness of the Plow Iron. The Plow is to make a narrow square Groove on the edge of a Board or Rail.
— From Randle Holme’s “The Academy of Armory, or, A Storehouse of Armory and Blazon” Book III, Chapter VIII, Plate 2.