I have dealt with this subject in the chapter on “New Buildings.” The model bye-laws to which I have there referred contain some excellent principles in reference to this matter, and too much power cannot be given to a local authority in respect of house drains, even to the extent of prohibiting any one else to construct them. The main sewer, shared in common as it is by all the inhabitants of a town, must be looked upon as a common danger, and each house that connects with it should so far as possible be severed from it; at the same time the drain must be so constructed that the sewage reaches the sewer as quickly and as completely as possible, without any nuisance or knowledge of the unpleasant nature of its contents or those in the sewer reaching the inhabitants of the house: this is the key-note of all house drainage, and many excellent books and descriptions of this class of work have been from time to time written. (3.) The next duty of the town surveyor is to inspect all defective drains within his district, and serve the necessary notices, &c. This duty is embodied in the following clauses of the Public Health Act, 1875: “Where any house within the district of a local authority is without a drain sufficient for effectual drainage, the local authority shall by written notice require the owner or occupier of such house, within a reasonable time therein specified, to make a covered drain or drains emptying into any sewer which the local authority are entitled to use, and which is not more than one hundred feet from the site of such house; but if no such means of drainage are within that distance, then emptying into such covered cesspool or other place not being under any house as the local authority direct; and the local authority may require any such drain or drains to be of such materials and size, and to be laid at such level and with such fall, as on the report of their surveyor may appear to them to be necessary. “If such notice is not complied with, the local authority may, after the expiration of the time specified in the notice, do the work required, and may recover in a summary manner the expenses incurred by them in so doing from the owner, or may by order declare the same to be private improvement expenses. “Provided that where, in the opinion of the local authority, greater expense would be incurred in causing the drains of two or more houses to empty into an existing sewer pursuant to this section, than in constructing a new sewer and causing such drains to empty therein, the local authority may construct such new sewer, and require the owners or occupiers of such houses to cause their drains to empty therein, and may apportion as they deem just the expenses of the construction of such sewer among the owners of the several houses, and recover in a summary manner the sums apportioned from such owners, or may by order declare the same to be private improvement expenses” (38 & 39 Vic. c. 55, s. 23).