instances, a depth of 7 inches of deposit had been flushed out of a pipe of 15 inches diameter, in ten minutes, leaving the pipedrain perfectly clean.

Fig. 5.

Precautions were necessary, to prevent sand, mud, or rubbish being introduced into the pipes whilst they were being laid; and the surfaces of roads, streets, and yards should be kept well cleansed, in order to prevent the dirt from being washed by heavy storms into and being deposited in the pipe sewers.

Woodcuts, Figs. 5, 6, 7, and 8, exhibited the details of a

manhole in a brick sewer, with side junctions from pipe-drains; and with a loose flushing-board fitting into a groove sunk in masonry. The manhole-cover could be lifted off by means of a key, in order that the sewers might be examined. Stepirons were fixed in all the manholes. All side junctions of pipe-sewers, or drains, with brick sewers, were made with stone. Junctions were also now made of earthenware, and were preferable. The lamphole-cover was removable, so that a lamp, or light, might be lowered opposite the end of the sewer, in order to discover any stoppage.

failures, he must give as the result of his experience, that they had occurred quite as often, in using the ordinary system, as with that which he had been accused of unduly advocating.

Mr. RENDEL,-President, said although the Paper only professed to deal with the generalities of the question of the drainage of towns, it had been necessary to consider the materials employed in the execution of the works, as to Engineers the practice was as essential as the theory, and in fact it

appeared, that the failures had chiefly occurred from want of the former; although it was contended, that the latter was not by any means faultless.

It had not been practicable to avoid direct allusions to the General Board of Health, and frequently in rather strong terms; but they were addressed to the official body and not to individuals, and then only for the published opinions, and the acknowledged practice of the officials, which were fairly open to animadversion; whereas, the strictures of the Board of Health, on the received practice of the profession, were as uncalled for and erroneous, as the theories promulgated in the blue-books published by authority.'

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The object of the discussion had been, not to determine whether large sewers were superior, or inferior to pipe-drains, but to consider the broad question, of the most efficient system of drainage for towns, to ascertain the value of the general maxims that had been laid down, and the influence they might have on the sanitary condition of the country. In doing this, any allusion to public Boards had only been made, by quoting from their published documents, and to the extent only of the opinions they had given, in their public capacity.

It had been assumed, that several of the speakers had come to the consideration of the question, not only with preconceived

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notions, but with a determination to condemn the pipe-drain system; this was so contrary to the spirit usually manifested at the meetings of the Institution, that he could not admit such a position, and the general tenor of the discussion proved, that the Engineers felt they could not receive as correct, either the statements put forth on authority,' or the deductions from the experiments; they had gone into the question of drainage, equally untrammelled by previous opinions, or by official dictation, and only animated by a desire to discuss the question on scientific and practical grounds, and for the ultimate benefit of the public.

The choice of the various qualities of the materials for pipes and bricks, for sewers, must be left to the judgment and experience of the Engineers; it was of considerable importance to the durability of the work; but so much depended on locality, that considering it would be better, not to import that branch of the subject into the chief question, which was the consideration of the system of town drainage to be recommended, and that the details of construction could be considered on another occasion, he had rather discouraged the discussion of the relative qualities of materials, and would suggest it as a good subject for a Paper during the next session.

The general question of sanitary reform was almost based on the adequate drainage of towns, and, it appeared to be admitted, by all who had directed attention to the subject, that the works, for the purpose, should be comprehensive and permanent, even at almost any reasonable cost, and with the example of Croydon before them, the authorities of even moderate-sized towns should hesitate, before, for the sake of economy, they submitted the drainage of the habitations of their fellow townsmen, to the risk of dependence on a system of inaccessible drains, instead of constructing adequately-sized main sewers. The investigations into the causes of the epidemic at Croydon, as well as the Reports ordered by the Metropolitan Sewers' Commissioners, relative to the results of the pipe-drain system in other localities, would materially aid, in arriving at the correct solution of this vital question, if undertaken with a right spirit, and from the character of the professional men who were engaged in them, there was little doubt of the valuable and impartial evidence which would be obtained.

The