After another extended struggle, I can reveal a construction of Serpentine Lattice Labyrinth (37,25), which has the desired repeat unit of 1994 squares, made up of two supertiles at right-angles to one another, and each comprising 997 squares. Finding this particular robust solution again involved serial attempts and failures, but the final failure revealed a passage to success. Here is the result, with one supertile in each orientation shown in black. Old Mitchell’s Almanac characterises this as an impressive tessellation. It liberates its bearers to act with flair and panache, but only after persistent and methodical footslogging.
997: Here in this year the raiding-army travelled around Devonshire into the mouth of the Severn, and there raided, both in Cornwall and in Wales and in Devon; then they went up at Watchet, and wrought great harm there by burning and slaughtering of men, and after that turned back round Penwith Tail to the south side, and then turned into the mouth of Tamar, and then went up until they came to Lydford, and burned and killed everything that they met, and burned down Ordwulf’s monastery at Tavistock, and brought indescribable war-booty with them to the ships’.
(Michael Swanton, ‘The Anglo-Saxon Chronicle’ (JM Dent, 1997) p. 131)
Better to be living in these than those days I hope. DJM