“How extremely simple it all is!” was the remark of a recent visitor at a sewage farm—which encourages me to venture on publication of the most recent discussions on a “problem” complicated by engineers, chemists, bacteriologists and inventors of systems, who have raised clouds of dust through which it is difficult for ratepayers and district councillors to find their way to “the best practical and available means of sewage disposal.” I have a belief that publication of all attempts to purify _the whole_ of a town’s sewage, rather than small scale experiments with equations founded on such data, is the desideratum. [Sidenote: 1872.] Having begun in the year 1872, with a pamphlet, “Will a Sewage Farm Pay?”[2] I desire to proceed with the present one thirty years later, as my humble contribution to a right understanding of the intelligent Scavenger’s business. At the earlier date agriculture was prosperous, and ratepayers of Exeter were just as confident that sewage farming would bring large dividends as some of the same city’s councillors are at present not in the least sceptical that their engineer’s septic system is the true specific for sewage disposal. In adhering to land as the natural and best agent, I have had the support of the Local Government Board with that of many Royal Commissions, notably the one now sitting, and I have naturally chosen cases where suitable land was accessible when I desired to demonstrate the efficiency and simplicity with which the powers of Nature can be applied for the use and convenience of man. Nor have I failed to study all “artificial” substitutes for the best means, wherever difficulties of obtaining suitable land presented themselves, e.g. my Canvey Island scheme for dealing with the sewage of London on a relatively small area, and other cases. Of late years I have welcomed the light thrown on this subject by bacteriologists, but lamented extravagant statements put forward by those who fail to see that the previously unrecognised microbes can do their work, as they have always done it, to most advantage in the upper layers of any porous land. [Sidenote: 1902.] An interim report by Lord Iddesleigh’s Royal Commission has, however, awakened such theorists to the fact that land is not to be discarded because it may not bring in a profit or because patentees of systems find it to their interest to contrast neglected or badly managed sewage farms with carefully nursed little experimental installations for artificial treatment of selected samples of sewage. Recognising the marvellous improvements in arts and manufactures of all kinds due to steam, chemistry and electricity, the public has naturally expected similar results from applied science in artificial sewage treatment, and there has been no lack of study of every imaginable process during the last thirty years. [Sidenote: 1884. Lord Bramwell’s Royal Commission establishes principles.]