From the PREFACE. The principal part of this book was written nearly four years ago. It has only been waiting in order that some suggestions it contains might have a thorough practical trial, and this being accomplished, it is now published in the hope that it may help those people who are in doubt and trouble with the drainage of their houses. It would be a public calamity if the wide-spread alarm, caused by the recent illness of the Prince of Wales, were allowed to subside without producing a beneficial effect; but there is danger that such will be the case, simply for the want of definite information as to what is amiss, and how it is to be set right. The discussion in the newspapers has been more calculated to cause alarm and bewilderment than to direct anyone how to act. Everyone is crying, "Do! do! " while no two agree what is to be done. What appears to be wanted is a book of approved scientific merit, and of such a practical character that a householder or any unscientific person can learn from it how to ascertain if drains are safe, and, if not, how to get them put right. In the absence of such a book, I venture to hope that this little work may be useful. My chief object in writing on this subject was to suggest a plan for preventing the evil which is now causing so much alarm-viz. the back-flow of gas into our houses. Of this plan I have now had four years' experience; and have, without exception, found it to answer perfectly. In the first place, I applied it to my own house at a cost of fifty shillings or thereabouts. This house is of the ordinary type, and is drained into a foul sewer. Before- the introduction of the new plan, it was never free from smells; while, since, there has been no annoyance of the kind, nor have the drains required any attention whatever. The plan is very simple, and can be applied to any fairly-drained house at a small cost, and without requiring the drains inside the house to be disturbed. I am not aware that this complete scheme has ever been suggested before; but it embodies as its principal features several plans which, I am pleased to see, are daily growing in favour; among which perhaps the most important is that of having a break or trough in the pipe which connects the house with the sewer. This has now been advocated for several years, but I do not know by whom it was first proposed. Besides describing the proposed scheme, I have endeavoured to impress the reader with its simplicity, and also to point out other ways in which the drains in a house may be harmful, besides by the admission of sewer gas-in fact, to make this a handbook on house drainage. With this view, I have divided the book into four sections....