P.S.--The _Gentleman's Magazine_ gives a plate of these tiles, as well as a
plate of some others with which another ancient building, called "Grand
Palais de Guillaume le Conquerant," was paved.
Alverton Vean, Penzance.
_Artificial Drainage._--Can any of your correspondents refer me to a work,
or works, giving a history of draining marshes by machines for raising the
water to a higher level? Windmills, I suppose, were the first machines so
used, but neither Beckmann nor Dugdale informs us when first used. I have
found one mentioned in a conveyance dated 1642, but they were much earlier.
Any information on the history of the drainage of the marshes near Great
Yarmouth, of which Dugdale gives passing notice only, would also be very
acceptable to me.