This phut would materially check the disgraceful practice of forcing rubbish through the gratings, as it would readily lead to the detection of the offending party.. It is also worthy of observation, that the sewers are at present the resort of a prodigious number of rats, who feed upon the offal thrown down the gratings; these rats come through the gratings at pleasure, and pass into the dwelling houses. By the new plan they could not do this; besides, they would find no food there ; and having no similar stronghold to resort to, it is to be pre sumed that their numbers would be quickly reduced by the arts of the rat catcher.
Immediately connected with this subject, is a patent taken out in 1822, by Mr. John Williams, of Cornhill, "for a method to prevent tha frequent removal of the pavement and carriage paths for laying down and taking up pipes, and for other purposes, in streets, roads, and public highways." The nature of Mr. Silliams's plan will be fully understood on inspection of the following drawing, representing a transverse section of the street. r r repre sents the paved road-way ; f, the foot-pavement ; 6, a section of 'the front wall of the basement btory of a house, with a pipe p to supply water from one of the mains o, contained in the suh-way. The opposite aide of the diagram is incomplete, having been cut off for want of room ; the pipe p there shown is for the supply of the house on that side, with either gas or water; the upper pipes, which may be supposed to belong to different companies, are suspended to the crown of the arch by iron straps. The lower pipes are supported upon
the floor ; m m shows the outline of the masonry; a, the common sewer, which has, at stated distances, openings into the sub-ways, but secured by air-tight doors, to prevent the escape of effluvia ; 1, one of the holes covered with a grating, for the admission of light and the circulation of air. The patentee proposes to build his "sub-ways," (as he terms them) when practicable, over the sewers, with drainage from them into the sewers ; the dimensions are about 7 feet high and 4 feet wide, but these may be varied according to circumstances. Openings are to be made on the tops of the sub-ways, or tunnel, at every hundred feet, for the purpose of admitting air and light; and passages are to be made in the sides to admit inspecOrs and workmen. Along each side of these tunnels are to be arranged pipes to supply the inhabitants of the streets under which they are built, with water and gas.
Amongst the advantages enumerated by the patentee to be derived from the introduction of sub-wave, may be noticed the facility with which a line of pipet may be deposited along street, without breaking up the pavement, and the ebnsequent annoyance to the inhabitants, obstruction to the passengers, and detriment to the stability of the roads ; the immediate access at all times to inspect the pipes, effect the requisite repairs, or obtain an additional supply of water in cases of fire, and better opportunities of repairing and clearing the common sewer, whether it be situated underneath or alongside of the sub- way.