No hard and fast lines can be laid down as to the best method to be adopted for the disposal of the sewage of any town, but the peculiar circumstances of each case must be considered before advice could be given on the subject: geographical position, physical arrangement, habits of the population, and the character and quantity of the sewage of the town being some of the most important. In any case it is necessary that the transmission of the sewage to the outfall should be effected as speedily as possible, and that the position of this outfall should be such as to cause no nuisance. The contents of the sewers should, if possible, be emptied by gravitation, as pumping is a constant expense, and economy with efficiency must of course be studied. Up to the present time the following are the methods adopted in this country for the disposal of sewage: (1.) Passing the sewage in its crude state into the sea or tidal river. (2.) Passing the sewage in its crude state over large tracts of land; this is called broad irrigation. (3.) Passing the sewage in its crude state on to small tracts of land previously prepared by deep drainage; this is called intermittent downward filtration. (4.) Mechanical subsidence of the sewage in large tanks, the effluent passing on to land or into a river. (5.) Mechanical filtration of the sewage, the effluent passing on to land or into a river. (6.) The introduction of lime or other precipitant into the sewage, which is allowed to settle in tanks, the effluent passing on to land or into a river. Very little need be said upon the first of these methods. Many engineers of high standing contend that, where practicable, the sea or the tidal estuary of a river is the right place for the sewage, as no costly works are necessary, and an abominable nuisance is thus got rid of at once and for ever. To ensure this, however, great care must be exercised in the selection of the site for the outfall. Float observations should be made, not only of the surface tides and currents, but also of those at different depths, and the effect upon the sewage by its different specific gravity from that of the salt water must be allowed for, as well as the difference of level of the tides and the configuration of the adjoining coast line.