in course of time they will in a very great degree be obviated. Good tile can be obtained at Cleveland, Columbus, Cincinnati, Woodstock, Painesville, Springfield, Clairdon, etc., in Ohio, at reasonable rates.

CHAPTER VI.

HOW DOES WATER ENTER THE TILES?

This question is asked by all persons who, for the first time, direct their attention to the subject of drainage, and the solution of the problem involved in the inquiry, is rather a subject of scientific interest than a matter of practical moment; for the water does find ingress, as experiment proves. But nevertheless, there are some practical bearings in the question which demand investigation.

In the ordinary arrangement of strata of earth, there is a very permeable layer or soil and subsoil, and below a less permeable stratum or "hard-pan." The water of rains descends to this stratum, and is there retained for a longer time than in the more permeable soils above; and it is a consequence of this retention that the upper strata become submerged with water.

"

When drains are laid much above the level of this retentive stratum, they do not begin to carry off the surface water until this has completely saturated the whole depth of soil from the "hard pan up to the level of the drains, which thus obtains the water which enters it from below. It was at one time supposed to be disadvantagcus to the object intended, if the surface water made its way immediately downward into the drains, as it was supposed to be not sufficiently filtered, and much of the soil enriching contents would be carried away into the drain, when it should have remained in the soil. To obviate the immediate descent of the water into the drain, it was recommended to cover the newly laid pipe with a layer of sand, or other porous material, two or three inches, and then overlay it with a covering of stiff clay, which would cause the more even and natural descent of the surface water to the impermeable stratum below, and its subsequent ascent to the drain level, into the bottom of which it finds entrance. But recent experiments have shown the fallacy of this doctrine. We have shown in the experiments of Liebig and others, that the soil at once absorbs all the nutritious properties borne down by the rains. The permeable strata will not yield their moisture to the drain until the point of saturation has been reached below.

The manner in which the water finds admission into the drain pipe, when it has once found its way to it, is very simple and easy of explanation. If the whole drain were one continued, unbroken pipe, submerged into a supersaturated soil,

a portion of water would find its way by means of what may be termed soakage, through the somewhat porous walls of the pipes, as water makes its way slowly through bricks. This soaking or sweating process would go on more readily through soft, poorly burned pipes; but in tiles very thoroughly burned, it would go on very slowly; so slowly as to defeat the purpose for which such tiles are laid down. The proportion of water, however, which enters the jointed pipes (the only ones used) by soaking, is so inconsiderable, that we must look for some other mode of entrance, in answer to the question, "How does it get in ?"

No jointed pipe can be made and laid down, in which the joints will fit sufficiently close to prevent the free access of water to the empty space within the tube. The facility for entrance, by this means, afforded by a pipe of any size, under four inches, 200 feet long, made of 13 inch sections, will exceed, by far, the capacity of the same pipe to discharge the stream which might thus find

entrance.

The water, then, enters at the joints, which cannot be made close enough to prevent its ingress, and when properly laid down, the water entering the drain has its course from below upward.

Kielman appears to doubt, that sufficient space would occur between the joints of twelve or thirteen inch pipe to carry off the water which would collect. But being satisfied that the joints were the only place at which water could enter, he manufactured tiles having a length of nine inches only, in order to facilitate the admission of water. This we consider very bad policy; because it makes not only more joints than are necessary, but because short joints are more subject to disturbances than long ones. In fact, sixteen or eighteen inch tiles afford sufficient joint apertures for all the water they can convey away. There have been many calculations with regard to the amount of space between the joints of pipes; Messrs. Shedd and Edson of Boston, have made some very accurate observations, bearing on this operation-so also has Vincent, already qoutedthis latter writer says, in effect, that water requires no other means of entering the pipes than the spaces at the joints. The inner circumference of a one-inch pipe, amounts to about three inches. If, then, the width between the joints is assumed to be one eighth of a line, or one ninety-sixth part of an inch, which, in all probability, is the least possible space which is likely to occur under ordinary circumstances, it produces an entrance space equivalent to one thirtysecond of a square inch. The section or opening of a one inch pipe would then have a capacity of nearly three-fourths of a square inch. Then, twenty-four or twenty-five joints, each having an entrance capacity at the joints of one ninetysixth of an inch, will have an aggregate joint entrance capacity equivalent to the caliber of the pipe itself. In less than two rods, we have upward of twenty-five

joints, therefore the minimum capacity of admission at the joints more than equals the caliber of the pipe every two rods.

But as it is not at all likely that drainage water will fill the pipes every two rods, the joints might even be made closer than one ninety-sixth of an inch, and yet admit all the water that is likely to find its way into the drain. On the other hand, there are scarcely any tiles manufactured whose joints will fit closer than one half a line, or the one twenty-fourth of an inch; therefore the water would find its way into the pipes in sufficient quantities, even if the tiles were two feet instead of one foot long.

CHAPTER VII.

HOW LONG WILL TILE LAST ?

This question has not been tested fully in this, and perhaps in no other, country. The length of time since the first pipe tiles have been laid down here, has not been long enough to determine this question. All the information that can be gathered from direct experiment, and analogical reasoning, goes to show that drains of properly burned tiles, may be considered "permanent" improvements.

A few references to known cases of durability of tiles, and other objects of similar constitution, may aid in arriving at a proper estimate of the indestructibility of tile drains.

In Wigtonshire, England, the celebrated Marshal, Earl of Stair, had constructed some drains of brick, laid upon the clay subsoil, beneath the vegetable mold, one hundred years ago, which, when examined after the lapse of that time, were found to be uninjured, both as to materials and permeability. They were laid, in one instance, by setting two course of bricks lengthwise, about four inches In apart, and covering the space inclosed by laying other bricks end wise across. another case, the drain was made by laying down bricks side by side, as a foundation, upon the edges of which other brick were set up sideways, and the whole covered with flat stones. In both cases the work was next inclosed with a packing of broken bricks, or "bats," and then earth superimposed.

In France, there are tile and brick drains laid down in the early part of the sixteenth century, still in good repair, and fit for the purpose intended, which proves sufficient durability to warrant the construction of drains (if properly performed), with the reasonable expectation that they will outlast the generation of those who perform the work. There are, indeed, in England, certain legal enact

ments and regulations made to promote and favor the construction of drains, which contemplate fifty years as the minimum period of durability which may be assigned to this species of improvement, if properly made.

The almost indestructible nature of the materials, when properly protected, may be inferred from the fact, that at Ninevah and Babylon, bricks have been exhumed after having lain in the earth for more than thirty centuries, in a state of perfect preservation. In Italy and Greece, specimens of ancient pottery are found, the age of which is often not less than two thousand years. Even in Ohio the antiquary can point to the remains of a very inferior kind of earthenware, of an age coeval with the mound-builders, the cycle of whose life and labors is lost in the utter oblivion of forgetfulness, while their fragile potters-ware remains to tell us that "art is long, though life is short," and insure the duration of the work of our hands, until our name, and even nation, may pass away and be forgotten.

In the Great Basin of Utah Territory, may be found the volcano-burnt clays of a period so remote in the world's geologic history, that no number of years can satisfactorily designate the durability which this clay, like that of our tiles in composition, has already shown, and no guess as to when the common causes of its destruction will have disintegrated it again, can assign the limit of its future per

manence.

The useful durability of our tile drains, depends upon the following circumstances: 1. A properly constituted clay, suitable for making a "hard tile," that is, a semi-vitrified product. 2. The perfect burning of this into properly shaped hard pipes. 3. The laying of these so deeply in the earth as to protect them from the frost, a most powerfully disturbing and destructive agent. 4. An observance of the proper rules of construction, so as to avoid curves, up and down, to such an extent as to favor the deposition of sand and rubbish, which may find their way into the tiles, through the crevices of the joints. Sand will be arrested at any depressed point in the course of a drain, and clog the conduit so as to prevent the flow of the water. And, last, the protection of the entrance and exit extremities of the pipes, from the admission of small animals, reptiles, and the like, or the treading of cattle. This object can be best attained by the use of tile plates, perforated with fine holes at each end, and inclosing the exit with a fence, or walling it up to prevent the cattle, attracted by the water flowing out, from treading the tiles to pieces.

In regard to the kind of pipes which are most durable, it may be remarked that "pale," or "soft" tiles are readily softened and broken by the action of the water, while tile may be made perfectly indestructible, if sufficiently burned,

by any means save violence, frost, or powerful chemical re-agents, against all of which means of destruction a proper mode of deposit will entirely protect it; and a drain thus constructed, can have no limit assigned to its useful durability. In common phrase, it will last forever."

CHAPTER VIII.

LAYING OUT DRAINS.

In laying out drains, the first thing to be determined is the amount of fall. Therefore, the lowest spot on the field or fields to be drained must be selected as the starting point. The amount of fall which can be obtained at the lowest point necessarily determines the depth of the drains. After having determined the amount of fall, the next thing to be determined is, whence comes the water? Should it be ascertained that the water comes from an underground spring, then a drain on the Elkington plan may be advisable. If the water appears in concavity, on the side of a hill, it will, perhaps, be well to examine the soil immedi ately underneath, and, if an impervious bed underlies, which is in turn succeeded by a porous bed, it may be bored through at short distances, drawing the water into the lower and pervious stratum. Should the water

make its appearance at the bottom of the hill, flowing over an impervious stratum, a drain might be dug parallel with the base of the hill, which will remove the water coming from above, and the spring will be cut off. Again, from the bottom of this drain auger holes might be bored through the impervious bed into the next below, should it be found pervious. (See illustration, Fig. 37.)

In this case the purpose is merely to collect and carry off springs that come to the surface-a knowledge of the character and arrangement of the earth a few feet below the surface, therefore, is very desirable. Where the water washes its way to the surface, in a layer of sand or gravel, lying upon a layer of clay or rock, as is usually the case, the work is very simple. A ditch or drain is made up to the foot of the hill or ridge, from some creek or other place, where sufficient outfall can be obtained; it is then carried along the foot of the hill or ridge, usually

FIG 37.