For1½inch pipes17s. 6d.per thousand.
" 2 " 25s. "
" 3 " 45s. "

Each tile one foot in length, and the one and one-half-inch pipes weighing 16 cwt. per thousand.

One of the great difficulties in connection with tile-making is, in many districts, to procure clay sufficiently free from lime. Tiles are very often sold by sample, sent a considerable distance, and it becomes necessary to test them, which we do (for lime) by placing them in water for a night; and, if lime is present in the tile, it will, of course, swell out, and break the latter, or leave it in a riddled state.

I have now endeavored to answer the queries in your postscript, and I have carefully avoided enlarging on some points in them with which your readers are already familiar. If I shall have thrown a single ray of additional light on this subject across the Atlantic, I shall be amply repaid for any attention I have given to thorough-drainage during the past twelve years.

I should here observe that I mislaid amongst my papers the portion of your letter containing the queries (it was a separate sheet), and it has not as yet turned up, so that I had to depend on a rather treacherous memory to keep the queries in my mind's eye. It is highly probable, therefore, that I have overlooked some of them. This circumstance was the chief cause of the delay in writing.

You are quite at liberty to make any use you please of this communication.

William Boyle.

INDEX.