I do not believe that the surface purification obtained by distribution over even the densest of clay lands was _effectively_ put in evidence, and too much weight was given to the difficulty of increasing the effective top soil on such land; but on the whole I think that the Interim Report is very satisfactory to the reasonable advocates of a preference being given to the adoption of a large area of land, where available, over any artificial treatment on a small area, other things being equal. At the time when the Interim Report was issued, however, a very full and careful examination of a select number of sewage farms was still in progress, and Appendix 22, with a casual mention by Dr. M’Gowan, affords the only glimpse to be had in the bulky Blue Books, of any results of that examination having been as yet adduced in evidence. The Commission’s officers, to my knowledge, were engaged for many months in examining, surveying and taking numerous samples of sewage and effluent at the Camp Farm, and, as they doubtless had equal opportunities of independent observations on the other selected sewage farms, the further reports of Lord Iddesleigh’s Royal Commission cannot fail to be interesting and instructive. On one point Appendix 22 to the Blue Book abundantly supports an opinion I have so often expressed, namely, that a good strong loamy surface is a more efficient purifier of sewage than many feet of barren sand. I refer to the curves in Appendix 22, showing the greatly superior purification effected at Nottingham with the best soil as compared to that of the sandy one at Aldershot, which, in its natural character, is about the worst for purification and for producing crops to be found in England. My experience, however, all points to the extreme importance of studying local conditions from the first inception of plans in each particular case, to their completion with the best available materials. But when the engineer has done his best, the sanitary authorities, having borrowed the funds to pay for the work, will take no further trouble about its sewage, and will often engage careless ignorant workpeople at inadequate wages to carry on the hourly varying labour, on efficient performance of which success depends. [Sidenote: Automatic appliances for sewage and effluent discharge.] It may seem idle to complain of boards and their employees showing little interest in the work of sewage disposal, but it is worse to pander to their failings by selling them automatic machines under the pretence that all the thought, and fertility of resource, required for efficient sanitary sewage disposal can be supplied by ingenious applications of hydraulics on the principle that sewage is a fluid, and, as such, will behave like clean water.