[179] The advantage of forming an air-chamber in the lower part of the gate, and allowing the water to enter above it, is that when the size of the air-chamber is properly adjusted to the weight of the gate, there need not come on the wheels, while moving, more than a trifling amount of weight.
[180] The arrangements of a buoyant gate have been explained above, p. 429.
[181] In the year 1856 and afterwards, Mr. Brunel was engaged in improving the navigable channel of the river Neath, at its embouchure into the Bristol Channel. A bank of furnace slag, for directing the course of the river, had been made previously by Mr. Palmer, and continued as far seawards as it was then thought could be done with safety. Mr. Brunel carried a training bank still farther, and succeeded in cutting off a bend of the river; Mr. Brereton has since extended the navigable channel in a straight line to low-water mark, a distance of two miles; and the bar has been lowered to within 1 foot of the level of the dock sill.
[182] Reports on the Paris Universal Exhibition 1867 vol. i., p. xxiv. 194
[183] When, at the close of the Exhibition, Mr. Brunel was compelled, much against his will, to accept a pecuniary acknowledgment of his services, he spent the money in the erection of model cottages at Barton, a village near his property in Devonshire.
[184] See Report of the Select Committee of the House of Commons on Ordnance, 1863, Minutes of Evidence and Appendix (ordered to be printed July 23, 1863):—p. 306, Report of Ordnance Select Committee; p. 44, Statement of Mr. Whitworth; p. 56, Evidence of Mr. Whitworth (Q. 1329-1337); pp. 58, 59, the same (Q. 1385-1410); pp. 402, 403, Papers delivered in by Mr. Isambard Brunel; p. 110, Further Evidence of Mr. Whitworth (Q. 2545-2551); p. 112, the same (Q. 2602-2610); p. 548, Letter from Mr. Westley Richards to Mr. Isambard Brunel.
[185] Captain Claxton, at Mr. Brunel’s desire, went for a voyage in Messrs. Ruthven’s vessel, the ‘Enterprise,’ in order to test her performances.
[186] This appears to be the only instance in which Mr. Brunel printed an account of any of his works.
[187] On this application of tin for the covering of the roof, Dr. Parkes observes (Manual of Practical Hygiene, London, 1869, p. 317):—‘In the Crimean War the roofs of Renkioi Hospital, on the Dardanelles, were covered with polished tin; it was found, however, somewhat difficult to place it so as to exclude rain, and the surface soon became tarnished. The thermometric experiments did not show a greater lessening of heat than 3° Fahr. below houses not tin-coated.’
[188] ‘At Renkioi, in Turkey, Mr. Brunel supplied square wooden sewers about 15 inches to the side; they were tarred inside, and acted most admirably without leakage for fifteen months, till the end of the war. The water-closets (Jennings’s simple syphon), arranged with a small water-box below the cistern, to economise water, never got out of order, and in fact the drainage of the hospital was literally perfect. I have little doubt such well-tarred wooden sewers would last two or three years’ (Parkes’s Manual of Practical Hygiene, p. 635).