Thomas Lloyd Betton, of Kansas City, Kan., writes:

"In preparing plans of foundation for a building we have arranged drain tile running around foundation. Tile is hubless, such as is used on farms for draining farm land. It runs about 8 inches above footing, and the architect wishes us to connect same to sewer, which has to convey water from two water-closets, two washstands, two bathtubs, two sinks, as you will see it shown connected in our plan. We say it is not proper to connect it to main sewer, for in case trap should become stopped up in any way everything from house would be forced back into the hub-less tile, and would be the means of saturating the ground around building before it would be discovered. Please give us your opinion as to whether the tile should be laid above or below footing."

[Two-inch cylindrical land tiles with slip collar joints should be used with Y branches and curved pieces for change in directions. The tiles should be placed on a plank bottom laid to grade of about 6 inches in 100 feet. The invert of the tile should be level with the bottom of the footing course at the front of the house (or at the point of discharge of the tiles), and should rise in both directions from this point to a "summit" at the back (or opposite side) of the house. Care should be taken to prevent mud from flowing into the drains while being laid. The joints in the tile are sometimes made with cloth or tar paper wrapping instead of slip collars. It is a good plan to fill in the trench with broken stones to a depth of 6 inches over the pipe and to cover this with salt hay or straw before filling in the earth. The outside wall of the house should be thoroughly plastered and troweled smooth with Portland cement mortar (1 to 2) and allowed to set before the tile is. laid. This plaster coat should extend from an inch. or two above the surface of the ground to the bottom of the footing course. A coating of bitumen laid on hot outside of this will make the foundation walls doubly proof against water and dampness. The discharge from the subsoil drains should not connect with the sewer if it can be otherwise disposed of. In case it is impossible to provide other means of draining the subsoil line, it may connect with the house sewer under the following conditions:

SUBSOIL DRAINAGE OF HOUSE FOUNDATIONS.

First - It must be independently trapped against the entrance of drain air.

Second. - The trap must be supplied with water from an unfailing source, and had best be connected with a rain leader or yard drain. The ground-water supply alone should not be relied on to furnish seal for the trap, as during dry seasons the subsoil drains may carry no water.

Third. - The subsoil drains should be effectually trapped against the back flow of sewage, which may be occasioned by a stoppage in the main drain beyond the junction of the subsoil line. For this reason it is perhaps best to connect the subsoil line on the sewer side of the house drain; as stoppages in the main house trap, which are not infrequent, would not then affect the subsoil line. For the purpose in view, the prevention of the back flow of sewage, a mechanical trap with a floating ball should be used. A failure in the operation of the mechanical trap, in case of stoppage in the house sewer beyond the subsoil junction, will result in flooding the subsoil drains with house sewage which is not liable to be discovered until some of the house fixtures fail to operate properly or until the flooded subsoils become offensive. This is a risk which cannot be overcome, and it is essential, therefore.

Fourth. - That the traps be located where they can be frequently and readily inspected and cleaned.

A convenient arrangement of traps to cover the points enumerated is shown in Figs, 1 and 2, in connection with which it will be noted that, when working properly, the trap B is supplied with water from a yard drain or rain leader. The trap C, Fig. 3, is a ball float mechanical trap allowing the subsoil water to flow into B, but preventing back flow of water or sewage when the ball is seated. If C runs dry, B prevents the back flow of drain air, and, in case of the back flow of sewage, the first entrance of sewage into C would float the ball and seat it. The rain leader should be carried up with iron pipe and tight joints to the height of the fresh-air inlet, or abova the level of a yard drain, so that sewage backing into the leader may not escape until it has found its way out at some opening, where it will be a nuisance and be brought to the attention of the householder.

The traps, as shown in the drawing, can be grouped in an oval manhole 4x3 feet.

From what has been said it is evident that you were right in saying it would not be proper to connect the subsoil drain as shown in your sketch. The correct method of laying the tile has been indicated. If laid below the footing course, it may undermine it and crack the wall; if laid above the footing course it is not draining the subsoil to the greatest available depth. Plans for removing ground water from a house to sewer are also shown on pages 45 and 46 of "House Drainage and Plumbing Problems."]