CXLVII. In this quarter on the dexter side, is an upright Pole of strong Timber set an end, having many Pins put through it, made of sound Wood, or else of Iron. This is an appurtenance belonging to the Crab, mentioned numb. 148. and is to hang a Pulley or Snatch Block thereon, by which heavy Timber is drawn to a considerable height. Such an Engine as this with Pins all along it, was in former times used for to scale or clime up an Enemies Wall, and thereby to surprise a Town or Fort.
A. 3 such in Bend Pale-wise S. is born by Commander.
The second is a Snatch Block, or a double Snatch Block. With this Engine, with the appurtenances belonging to it, as Ropes and Tackles, great Trees of Timber are drawn up to a considerable height.
CXLVIII. He beareth Argent, a Crab Engine, Or. This is born by the name of Crabbe. This is an Engine used in Carpentery for the management of their heavy Timber, and to ease an hard Labour: It is only a square Frame of strong Timber, with a thick Plank 4 or 5 inches thick, fastned on the top of the frame, and the like on the bottom, through which goeth a strong Rowler, which is turned in the holes of the Planks, by the help of Hand-spikes or Levers.
CXLIX. In the Dexter side is an Hand issuant, holding of a Plumb line, with a Line rowle, at the end of it. This is the coat of Arms of Plumbley, being in an Azure field. This is a way that Carpenters use to try the upright standing of Posts, or other works that are to stand perpendicular to the ground plot; by holding the end of the line between the finger and the thumb, a little distance from the corner of the post, or work, and if the line and corner of the post be parallel to each other, the work is upright, else not.
The Second figure is a paire of Great Screws, of some called House Screws, for by the help of them, an house whose sides stand crooked, or have the Wall Plates sunk, are raised up and set streight by screwing up every peece into the place from whence it is fallen. se numb. 142. are the like for form, but in these the screw goeth through but one Plank, the other plank the Screw ends, only turn in a round hole made Concave.
In the Sinister side, is an other maner of Engine, and I suppose made for the same use as that mentioned in numb. 145. though it be of an other fashion on the top. Such a Jack Engine, with a Bended Head, I find to be an ancient Badg belonging to the Earle of Oxford.
— From Randle Holme’s “The Academy of Armory, or, A Storehouse of Armory and Blazon” Book III, Chapter VIII, Plate 2. Why am I reading this?