Because such a striking success has been recorded at Bradford, it is not to say that the self-same method would be equally profitable at other places, especially those handling what might be termed purely domestic sewage. The conditions existing at the Yorkshire city are peculiar, owing to the wool-washing trade. The process which is more likely to make the widest appeal, being the one adapted to meet the average conditions, is that which has been installed in the borough of Oldham. This is the invention of Mr. J. Grossmann, M.A., Ph.D., F.I.C., the well-known chemical engineer, who has made the exploitation of sewage his life-long study. The plant in question was laid down in 1912, being set in operation in October of that year, since which date it has been working without a break, giving the most satisfactory results. At the time the installation was carried out the population of the borough was 148,840, and both the water-carriage and sanitary-pan system were in vogue, although the latter was giving way to the former method at the rate of about one thousand per year. As the conversion system was carried into effect the quantity of sludge which the sewage works were called upon to handle increased, the quantity pressed in 1911 being nearly 8,000 tons a year as compared with 4,000 tons in 1899. This did not include the several hundred tons which were dealt with in lagoons without pressing. As the quantities of pressed sludge increased so did the difficulty of disposing thereof. The outlook was somewhat disconcerting. The agricultural land in the vicinity could only absorb a portion of the available volume. The necessity to incur the expense of carrying the residue a considerable distance to dispose of it, which solution would have proved somewhat costly, appeared to be inevitable. Experiments innumerable were carried out, but to no purpose. Agriculture, which is regarded as the obvious outlet for such material, was adverse to the proposal to absorb the accumulation for the land, because it carried approximately 15 per cent. of grease. The only escape from the dilemma appeared to be the installation of further presses with the attendant expense for auxiliaries to yield a dry material, and then to pay for the cartage of this residue to some convenient tipping ground or carriage of the settled sludge to sea to be dumped. As a round 30,000 tons of sludge would have been involved, the sea-dumping expedient would have been extremely costly. Further consideration of the question established the possibility of converting the material into a marketable manure, but this would have required the utilization of a trade process and also would have incurred expense.