REPort YRESENTED TO THE THRONE ON THE vant or THE YeLtow River siTvaTep uetow CHINASFU.
(Specially translated for the North-China Dairy News.)
Another capital point is the protection of banks, Lhave already spoken' of the disastrous effects of currents, which crumble and swallow up the earth, turning it into mud which chokes the river-bed, thus creating obstructions everywhere, and giving rise to the formation of shoals. In the "loess" region, all those sediments are carried off the banks, even in exceedingly larger quantities than on the lower course of the Huangho.
The protection of banks is, therefore, of the very greatest importance. I will say of this work what I have said about the previous one, that is, the mode of execution depends on circumstances.
Generally speaking, it would likely be sufficient to give to the slopes a necessary incline, covering them with well-made turf, and suitable plantings. In other cases, the foot of the slopes should be strengthened by pilings, wicker-work made, and walls of unbound stones erected: and, on those points where the current is strongest, the surface should be covered with bound masonry. Retaining walls should be built, and, when necessary, the base should be protected by means of luge rocky blocks piled up.
In the "loess" or yellow earth region, it might be suitable to fit in the sides of the igh cliffs layers of masonry capped by unbound stonework.
In all cases, it is absolutely necessary that all possible known means should be used to resist the erosion of the banks.
For regulating the current, and maintaining in its normal position the axis of the river bed, defence works would be necessary; they would, of course, vary according to the different points considered. It would be nearly impossible to foresee them at the moment but they would have to be done principally at the bends.
Scarfings, too, migh' be employed, lying mostly underwater, and made of fascine-work, wickerwork or masonry, according to the case.
The fascine-work should always be made of substantial materials, and millet straw, the only one employed nowadays, should he discarded, None should be used but strong materials, expected to be durable, It might be convenient to study the question of weirs to be eventually constructed.
These weirs would work only in case of exceptionally high rise of water, ordinary flows would find a natural outlet through the river bed itself. They should be constructed in the very dams themselves, and should be made to act on different levels. Their location could only be determined by a complete study of the region surrounding the river, and of the water-course into which the excess of the flows would fall.
"Wherever situated, the weir should be built of solid masonry-work, and should communicate with a strongly dammed u canal, or with a river having a wide bed, mostly unoccupied during the flows of the Huangho. Should an existing water corse be use as an draining canal, it should he made sure that the dams are strong and high enough, the inclines sufficient, and the bends not dangerous.
The mouths of the Huangho are at this time, as it were, closed by sand banks, To remove those where the sand is said to agglomerate, it seems to me that dredging would necessarily have to be resorted to: but the work could not be accomplished till after piers, projecting out to sea, should have been built: those piers which could not, I believe, be dispensed with, would in fact be the continuation, in the sea, of the river banks.
The sand settles at the mouth: this would be obviated by giving to the waters which brings it on a speed sufficient to send the sediments far-off into deep water. The result would be arrived at by compressing the inflow of water in the river, so as to increase its speed. The waters would dig out their own way; should they not succeed at first, then dredging operations would have to be carried on in the pass, which would afterwards be cleared by the water itself.
The above proposals are not meant to frighten any one, although it is not possible, without a close study, to estimate the cost of such piers. Similar undertakings have been accomplished at the mouth of many rivers, and their efficiency is well proved by the Mississipi and Danube works, I shall quote another instance: viz the mouth of the Seine river, which was one of the most dangerous for shipping, on account of the obstruction offered by sandbanks at its entrance. Longitudinal jetties were constructed, leaving between them a space of 300 metres, consisting merely of piled up blocks of rock and above the mean level of the highest tides. As an immediate result, the depth of 11 feet was increased to 20, which induced the promoters to continue and complete the work. I might also quote the mouths of the Garonne, the Loire, the Adour, and of the Meuse: this last one, a river flowing in my country, the length of which is greatly inferior to the length of the Huangho, but upon which numerous and important works have been under. taken,
Text read from the printed page and cleaned; old type leaves the occasional error.