Mr. Smith somewhat modified his views during the last years of his life, especially as to the depth of drains, and, instead of shallow drains, recommended a depth of three feet, and even more in some cases; but continued, to the time of his death, which occurred about 1854, to oppose any increased intervals between the drains, and the extreme depth of four feet and more advocated by others. The peculiar points insisted on by Smith were, that drains should be near and parallel. His own words are:
"The drains should be parallel with each other and at regular distances, and should be carried throughout the whole field, without regard to the wet and dry appearance of portions of the field—the principle of this system being the providing of frequent opportunities for the water rising from below, or falling on the surface, to pass freely and completely off."
Mr. Smith called it the "frequent drain system," and Mr. Denton says, that, "for distinction sake, I have ventured to christen this ready-made practice, the gridiron system," a name, by the way, which will, probably, seem to most readers more distinctive than respectful. Whatever may be the improvements on the Deanston method of draining, the name of Mr. Smith deserves, and, indeed, has already obtained, a high place among the improvers of agriculture.
VIEWS OF MR. PARKES.
About the year 1846, when the first Act of the British Parliament authorizing "the advance of public money to promote the improvement of land by works of drainage" was passed, a careful investigation of the whole subject was made by a Committee of the House of Lords, and it was found that the best recorded opinions, if we except the peculiar views of Elkington, were represented by, if not merged into, those of Smith, of Deanston, which have already been stated, or those of Josiah Parkes. Mr. Parkes is the author of "Essays on the Philosophy and Art of Land Drainage," and of many valuable papers on the same subject, published in the journal of the Royal Agricultural Society, of which he was consulting engineer. He is spoken of by Mr. Denton as "one whose philosophical publications on the same subject gave a scientific bearing to it, quite irreconcilable with the more mechanical rules laid down by Mr. Smith."
The characteristic views of Mr. Parkes, as set forth at that time, as compared with those of Mr. Smith, are—
"1st. Less frequent drains, at intervals varying from twenty-one to fifty feet, with preference for wide intervals.
"2nd. Deeper drains at a minimum depth of four feet, designed with the two-fold object of not only freeing the active soil from stagnant and injurious water, but of converting the water falling on the surface into an agent for fertilizing; no drainage being deemed efficient that did not both remove the water failing on the surface, and 'keep down the subterranean water at a depth exceeding the power of capillary attraction to elevate it to near the surface.'
"3rd. Parallel arrangement of drains, as advocated by Smith, of Deanston.