Some, however, are of wood, the material actually used for cubit rods by architects.
They resemble our yardsticks, being short (52.5 centimeters) and stout, with a quadrangular section and a fifth side produced by chamfering the front top edge (fig. The front, the oblique, and the top faces were used for marking and numbering the single measurements.
The string was fixed at the top of the two legs of the square, and the tip of the plumb had to touch the center mark on the cross board.
Builders' Squares Egyptian builders and masons made use of the simple wooden device, the square, in order to lay off or check right angles, in building as well as dressing blocks.
A rope 52.5 meters long would have to be very thick, and the knots for its subdivision would have been so bulky that it could not have been used for accurate work.
One might think, however, of different means of marking, such as the loops suggested by Reisner, fixed at a spot marked with red paint.
Such cords were of course not necessarily measuring cords or ropes.
There may also have been squares with a third piece of wood connecting the two legs in the shape of an A, similar to the square levels.
Apparently, stonemasons also used another measuring unit, the nby-rod, which might have been about 67 to 68 centimeters long, subdivided into seven spaces.
Unfortunately, there is not much evidence for its application and exact dimension.
The shape of this instrument appears frequently in the hieroglyphic sign used for words connected with the activities of that instrument, such as hh or sb. 58 in Petrie's Tools and Weapons has a base of 45.6 centimeters and legs 32.8 centimeters long; no.
They were found in the tomb of the architect Senedjem (Nineteenth Dynasty) at Deir el-Medina (fig. 59 has a base of 46.6 centimeters and legs 32.8 centimeters long.