On the scale of the value set upon that portion of the refuse of Edinburgh that has been appropriated for irrigation by the occupiers of the land in the vicinity of the city, the value of the whole of the soil of the city (not one-third of which finds its way into the irrigated meadows), if it were made completely available by an appropriate system of town drainage, would be double or treble the amount, producing an income of 15,000_l._ to 20,000_l._ per annum for public purposes. On the same scale of value it would appear that, in the metropolis, refuse to the value of nearly double what is now paid for the water of the metropolis is thrown away, partly from the districts which are sewered into the Thames, and partly from the poor districts which are unsewered, where it accumulates and remains a nuisance until it is removed at a great expense. It is allowed by Captain Vetch, an experienced engineer, and by other authorities, to be the most eligible plan in respect to economy as well as efficiency, wherever the levels were not convenient, or it were desirable to send the refuse over heights for distribution, that the contents of the sewers should be lifted by steam power, as water is lifted in the drainage of the fens, and that it might be sent for distribution, wherever it is required for use, in iron pipes, in the same mode as that in which water is conveyed into towns by the water companies. The estimated expense of this mode of cleansing and removal is about the same as the conveyance of water into towns, _i. e._, not a tithe of the expense of cartage, as will subsequently be shown.