Page 83 - Peter Randall "The Craft of the Knot.."

Whereas Square Lashing would be used to attach poles at right angles,
the Diagonal Lashing is used to keep two crossed poles rigid with respect
to each other. Scaffoldings made with a combination of these two
lashings are very rigid and secure.

STEP 1 Cross two poles diagonally, and make a Timber Hitch (see
Chapter 10) around them.

STEP 2 Pull the Timber Hitch tight and make three vertical wraps
around the center.

STEP 3 Cross over and make three more wraps around the opposite
diagonal.

STEP 4 Make two frapping turns, below the upper pole and above the