1842.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



341 



he puHcr of Jiainirg laml, on whatever sub-soil, resting, and rendering it 

 thoroughly and completely dry. The purpose of this lecture is to illustrate, 

 first, the principle on which this system acts; then, to show the advantages 

 which would arise to the agriculturist in carrying on the diflerent processes 

 with respect to the various crops ; and then to explain the modes employed 

 to render this drainage effective, both as to the cutting of them, and to the 

 preservation of the openings made for the escape of the water. 



[Mr. Smith here illustrated by a diagram, his method of thorough drain- 

 ing; the soil, the subsoil, the drains, &c. being represented.] 



In referring to two lines, representing the directions of drains, he stated 

 that he had drawn one at a greater inclination than the other, to show the 

 advantage of making the drains deeper than they generally were. The pre- 

 vailing practice was to make the drains two feet deep, but he preferred an 

 additional six inches — for this reason — that it was of great importance to 

 allow the water to go off as quickly as possible, and this advantage was 

 secured by cutting the drain to a greater declination. People were apt to 

 suppose that at a great depth water would not go off at all, but this w,is 

 a mistake. Another advantage arising from a deep drain was that it allowed 

 the whole bank of soil to become completely dry. and it consequently re- 

 quired a very heavy rain to wet it. The action of the atmosphere, too, re- 

 quired to be taken into account. He would not enter upon the chemical 

 question, but it was well known that soils were much improved by the 

 action of the air, and this advantage could only be secured after the water 

 was withdrawn. 



To render the field completely dry, it was necessary that a great number 

 of drains should be cut, and that they should be laid off in parallel lines 

 beginning at the highest side of the field. This secures a thorough dryiiicr. 

 and it has been found that when the lines run parallel, much greater effect is 

 produced than when they are drawn across. When drawn across, the draiUj 

 may catch the water, but experience has shown that it does not run of! so 

 readily. 



With regard to the distance at which the drains should be placed, that wil' 

 depend on the nature of the soil. If the field has been subsoiled, it is o* 

 less importance ; because the plough will form artificial channels in the soil 

 below. If it is a stifl' soil, it will keep long upon the surface ; and the more 

 free the soil is. the greater tendency it has to allow the water to pass ; so 

 that you will find that, on a stiff soil, such as the stiffer clays, taking into 

 account the nature of the subsoil and the soil itself, about the same drain 

 will serve on all soils. The distances in use are generally from 1.5 to 20 feet ; 

 in some soils individuals have been induced to put in the drains at 12 feet ; 

 but I conceive that that is, in some degree, throwing away money. From ob- 

 servations which I have made myself on all sorts of soil, in diflerent parts of 

 the country, I am inclined to recommend about IS to 20 feet as the distance 

 from one drain to the other. 



The way in which I usually proceed in draining, is, first to find a good 

 bottom-level to run the drain into. And here I may remark, that in some 

 parts of the country there is sometimes difficulty in getting an open level to 

 carry off the whole water of the district ; but I think that by a proper ap- 

 plication of the principles of engineering, it may be accomplished in most 

 situations ; because it is found that if proper channels are executed, a larger 

 quantity of water will be di>:charged with a very small fall. In an instance 

 in which I was engaged in the endeavour to carry off water, I found that in 

 a drop of four inches in a mile, thirty feet wide and six feet deep, I could 

 discharge 300 tons of water per minute; which is much more than would 

 fall in a very extensive district indeed. So that I have no doubt, it means 

 be taken to carry off the main level, that a fall mav be had. 



With regard to the fall of the great main, the receiving drain, I should 

 make that drain if possible about four feet deep— three feet six inches will 

 do ; but in order to have a drop from the one drain into the other, I usua'ly 

 make the main drain four feet deep, the receiving drain three feet deep, and 

 the parallel drains two ftet six inches. When there is any rise in the ground, 

 or any hollows over which the water can very well flow, it is necessary to 

 make a cad's drain That should be made about six inches deeper than the 

 other drains which fall into it ; then running on. it discharges itself into the 

 main drain. 



With regard to the manner of executing the drains, there are various 

 modes recummende.l, and I have found, on looking to land which has been 

 drained a great many years, that when the draining has been performed 

 carefully, all the different modes employed for the purpose of keeping the 

 drains open have been quite effective. Indeed, a great deal of the want of 

 effect in the duration of drains has been owing to the bad execution. In 

 some instances faggots have been introduced for the purpose of preserving the 

 openings of the drain, an.| these have been found to continue and to preserve 

 the openings in a perfect stale for nine years— in some instances I have as- 

 certained for twenty years. 



In Scotland the peat-top is frequently used to form the tiles for drains. 

 It does pretty well in clays which are pretty stiff, but does not do so well in 

 softer soils; in the same way, in some of the sandy soils, the sides not being 



sufficient to resist the pressure of the top. the tile gradually sinks down and 

 closes up the drain. 



Another mode of filling drains is by stones broken into the usual size for 

 making roads : and, although much has been said against the use of this sort 

 of filling, I have found from experience that when properly executed the 

 work is as durable as can be requireil. In most instances where stones can 

 be had, and where tiles are expensive, I should very much prefer them to the 

 tiles; and there is this advantage connected with it, that it prevents any 

 virmin from travelling in the openings of the drain, such as rats and mice, 

 which do a great deal of mischief. The great point is, to be very careful in 

 covering over at the top. As soon as wet comes, the sand and other mate- 

 rials silt down into the stones, and they are completely choked up. I have 

 'ound that drains not carefully executed, were completely destroyed in the 

 course of a cr,uple of years. On the contrary, if drains are so packed that 

 the water falls down on both sides, (the parts over-lapping each otherj there 

 is no opening whatever for the sand to find its way down. If drains are 

 carefully cleared in this manner, I will warrant their duration for almost any 

 period of time. I have executed myself about 1.30 miles of drains in this 

 way, and have had them all filled with stones; many of them have been 

 done 15 years, and there has not been a single instance of failure. 



Many persons who have visited my farm have asked whetlier or not the 

 drains ivould be choked up in particular positions. I liave always asked them 

 what positions they referred to. and have opened it that they may see ; and 

 in no instance have I found a single drain choked up. I have the drains of 

 100 acres all discharged into one pond, provided for the purpose of seeing 

 how much deposit came from the drain ; and although we have had heavy 

 rain, I have never seen the water in the pond tinged as if there was much 

 soil in it. I can, therefore, safely recommend stones as a very sufficient 

 drainage ; and in many parts of the country it is much cheaper than tiles. 



The next filling which has been used for preserving the openings of drains 

 is the drain tile. These are usually made of clay, and burnt. They are 

 found to be very handy and very useful : and where stones are not to be had 

 they are to be preferred. But there are districts where the clay tile cannot 

 be procured at any reasonable price ; they are usually 30s. a thousand, but in 

 some districts they are not lo be had at all. Lord James Hay has recently 

 discovered a method of making them of concrete stones cemented by lime ; 

 and so far as I have made any calculation of the expence, I think that in 

 most instances they » ill come considerably cheaper than the brick tile, and. 

 If executed on the ground, where they will not have to be carried far, the 

 breakage will be found to be very little, and they will be found to le exceed- 

 ingly durable. We know that the cement made of lime is more lasting when 

 covered up than if exposed to the atmosphere ; instances of this may be 

 found in the lime frequently discovered in old buildings, which has been found 

 to be perfect after hundreds of years. 



There are two other modes of making drains— peat earth has been cut into 

 a shape somewhat like a hollow wedge ; and a sort of instrument has been 

 made for the purpose of cutting peat earth into the form of the tile, so as to 

 produce an opening not liable to the objection of the wedge, which frequently 

 sinks and fills up the opening. A stone is frequently used to lay the concrete 

 tile upon, and prevent its sinking. It is also made of concrete. 



Much has been said with regard to the application of this system to diffe- 

 rent soils ; and many persons have expressed the opinion that, in some of the 

 very stiff' clays, drains of this sort would not be eflScacious, and that the 

 application of the subsoil plough after the draining would have no good 

 effect. With the view of showing the beneficial results, both of draining and 

 subsoiling, I have brought some specimens of different clays, in order to show 

 what improvement can be made. Here is a piece from the Pass of Stirlin"-. 

 This kind of soil has been cultivated from a subsoil, and has been known to 

 produce excellent crops of Swedish turnips. Here is another very hard clay 

 from Yorkshire. 



A gentleman inijuired how long after the subsoiling the land cssumed a 

 different character. 



Mr. Smith— Almost immediately— in the very first year. It requires some 

 years before it becomes adapted for a turnip soil. I have a specimen of some 

 soil w hich twenty years ago was so extremely stiff from the alluvial deposit 

 in the Pass of Stirling, that it required to be broken with large mallets, to 

 reduce, mechanically, the great lumps of soil. Thorough draining or sub- 

 soiling w as never thought of till about twenty years ago, w hen this land was 

 first drained; and now they get from it very splendid crops of turnips, and 

 in almost any season. Here is a piece of the improved subsoil before having 

 been drained by the subsoiling, the same as the other. While we are on this 

 point, I will produce the two specimens of subsoil from my own farm. 



A gentleman wished to be informed of the nature of the soil in Mr. Smith's 

 farm. 



Mr. Smith — It varies. In some parts it is sandy clay, and in otiiers, clay 

 perfectly impervious to water. When 1 first began to subsoil there was not 

 more than three or four inches of active soil, properly so called, for growing 

 plants; after a labour of about fifteen years 1 have nowanactive soil of six- 

 teen inches, and can turn over that in any part of the farm. 



