As much as a rate of 16,000 cubic yards (1,000 cubic metres) per hour has been attained in this way Buenos Aires. The local dredger, it is hoped, will lift at a rate of about 6.000 yards (say 4,500 cubic metres) er hour. In the Yangtze only about one-third the working time is to be spent in dredging, the remainder being occupied in' transport and dumping.
As the Yangtze mud is heavier and riner than the Buenos Aires material the dredger has been provided with about 0 per cent. more power.
The drag head In the early Fruen-Ung dredger was placed at the stern, but, to give better trim. and steer-many modern. vessels have the drag in the centre. This necessitates two engine rooms and a larger personnel, but is almost certainly preferable from the dredging aspect.
It is not my object to give an borate discourse on the dredger, the problems of which have engaged much of my time for the last sixteen years, but. simply to indicate the fundamental features.
Pioneer Work proposing the toa [Shanghai Association of 1 of Civil Engineers, Me. Av J. Percival 'There are one of two facts with which I think you will all agree with me about civil engineers in China One is that members of the Institution have rarely been given the credit' they deserve for" their great pioneer' work in the construction of (a) The sand pump.
(b) The rotary cutter type whicn can" deal with "mud And (c) the drag type.
The Sand Pump A sand pump in the simplest, form is just a centrifugal pump with a suction pipe resting on the sand.
pumped. The water driven to the Induced vacuum by the atmospheric pressure picks up the sand by erosion and a thin mixture proceeds up the pipe. As sand settles very easily In Water, "the excess water can" be drained off in the receiving vessel and gives little trouble. The quantity of sand is rarely more than 20 per cent. by volume of the water pumped. With Jets which will break up the material this type also pump mud and this ig the local practice for emptying mud barges into shore reclamations.
The rotary cutter type, of which there is also a new local example, has a helical cutter which breaks mud into. lumps go that they may washed up. the suction pipe in the same way and here again 20 per cent. by volume is a good figure. 'The ement is only sullable for reclama-long. on' account of its enormous water content and slow separation. Furthermore this type of -dredger works best_on a deep short cut, 50 that it should be moored by anchors oF spuds, For ocean bars of great size, it ty essential that dredging should long rather than deep so that if possible a scraper action is advantageous and it was the virtue in Fruehline's inventions (1898-1902) that he realized how the scraper action could be made to Increase the proportion of spoil in the sucked mixture s0 that hopper capacity of a sea-going Hes and in many other folds.
But perhaps more valuable still has been the professional spirit of service and the unwavering loyalty to the highest traditions which members of your honoured institution have conspicuously displayed.
The Institution's charter defines the tion of the engineer as. bel direct the great sources of pow-el ing for in nature for the use and convenience of man". As an instance of the special dimcuities that arise in performing that function in Chine, T would mention an experience I had couple of weeks ago in the prov: nee of Kiangsi where it was explained to. me that power-driven rollers could not be adopted on the hundreds of miles of reade they are constructing, because so doing would throw out of employment an aver~ Jage of sixty coolies "per mile who fare now pulling rollers.
Nowhere in the world to-day is the engineer allowed freely to perform this function as defined by' the Institution and everywhere progress being badly hindered if not block-Jed for that reason, "The Stout Fellows In proposing the health of the guests, Mr. C.D. Pearson eid We have here to-night an old friend of ours—a friend of mine for 96 years—who obtained promotion and, in fact, rose to the top with louch celerity that he had neither the necessity nor the time to sit for that infernal assies. Exam. T re-for, of course, to our old friend Chartes Harpur whom we refuse to ook upon as a guest.
We have here to-night representatives of kindred societies and of our
Text read from the printed page and cleaned; old type leaves the occasional error.