This formed, and still forms in many places, a very common arrangement for water ballast steamers, although not so inherent a feature of the vessel’s structure as the continuous-cellular bottom. In most cases this system is fitted only for part of the length, and not, like the cellular system, applied throughout the whole length of the ship. If it was impossible for the Board of Trade to hold by the contention that cargo might be carried in bottoms of the structural cellular type, it is equally untenable in the case of bottoms such as are now referred to. The difference between the two kinds of ballast bottoms is one merely of construction, and if any one of the two lends itself to cargo-carrying purposes, it is certainly the cellular system. The anomaly is sufficiently striking to merit attention, and in certain districts where the girder system is largely adopted for medium-sized vessels, it is felt as nothing short of an injustice, both by shipowners and builders. The concession or victory won by Messrs Denny removed a serious hindrance to the spread and general adoption of the water ballast cellular system. Other Clyde firms at the same time—or at least soon after the adoption of the system by the Messrs Denny—took the matter up and independently did much towards the popularisation of the cellular mode of construction. Speaking in the early part of 1880, Mr William John, of Lloyd’s Registry, now General Manager with the Barrow Shipbuilding Company, said:—“At the time Mr Martell read his paper on water-ballast steamers before the autumn meeting of this Institution (Naval Architects) at Glasgow, in 1877, there had been only two or three small steamers built (since Mr Scott Russell’s early ones) on the longitudinal principle. Now, it is within the mark to say there are one hundred steamers, built and building, whose bottoms are constructed on the longitudinal principle, or what is better described as the cellular system, amounting probably to 200,000 tons, and it is not outside the bounds of probability that a very few years will see the majority of merchant steamers constructed in this manner.” Mr John’s connection with Lloyd’s at the time, entitled his statements and opinions with regard to the prevalency and prospects of cellular construction to be accepted with every assurance, for it is in such Societies as Lloyd’s where the best consensus of information regarding the extent and tendencies of particular types of vessels can be obtained. In point of fact, the intervening period has witnessed, in great measure, a realisation of Mr John’s forecast. The advantages of a cellular bottom as regards safety, and for the purpose of ballasting and trimming vessels, also as meeting the greater need for longitudinal strength caused by the enormous growth in the size of vessels, have received that appreciation from shipowners and shipbuilders which is their due. The practice has accordingly spread, till now, it would not be rash