958
THE HONGKONG GOVERNMENT GAZETTE, 27TH SEPTEMBER, 1890.
[* Gazelle, p. 947.]
[* Gazette, p. 955.]
[* Gazelle, P. 947.1
Hall, the Cricket Ground, the Naval Yard, and the Military Cantonments, should have been shewn tinted pink between Queen's Road and the sea, because within their boundaries there is no legal restriction against native structures, and because there is every probability in view of the continued influx of Chinese from the mainland, of the ground being covered by such structures partially if not wholly. Nor are even the Military Cantonments themselves altogether safe from a similar fate, for there is actually a scheme under the consideration of the War Office for the sale of a portion of the Military lands for Chinese building purposes in order to raise funds for the erection of European Barracks on more important sites elsewhere. Mr. LEIGH should therefore have shewn one long littoral strip of pink colour embracing the whole of the lower city, except the patch above men- tioned, and if he had done so it would have been patent to anybody at the first glance of his map, that the Separate System sewers of the yellow portions having to be carried through the pink portions, had best be utilized by the Chinese as well, for the disposal of their foul waters.
7. At page 4* of his letter Mr. LEIGH states that his opposition to the Separate System is due to three different reasons. His first reason is that it will not be possible to separate the rainfall from the sewage of native tenements. He says, in this connexion, that the rain from the roofs and backyards of houses cannot be led away as proposed by Mr. COOPER, by means of surface-gutters passing from backyard to backyard because the owners of the houses will be likely to stop up the gutters at the communication-holes in the divisional walls between the backyards, or else because leaves or sticks may choke up these communication-holes with the result that the ground floors would be flooded and trouble caused. Therefore Mr. LEIGH proposes, in lieu, that the storm-waters should escape as at present through the foul-water drain of the house.
But at page 13* of his letter Mr. LEIGH describes the foul-water drain of the house as being generally choked up with vegetable matter, fruit-skins and other solid refuse. On his own shewing therefore he takes us from the frying pan into the fire for it will be clear to the merest tyro in Sanitation that Mr. COOPER's open surface- gutter can be kept unobstructed far more easily for the escape of flood waters than Mr. LEIGH's varicose underground house-drain. But in fact there are no grounds whatsoever for Mr. LEIGH's apprehensions that the house-owners will stop up the rain gutters. The Chinese are very neighbourly among themselves and would not be guilty of such silly acts of aggression towards each other, more especially as the passage of the surface-gutter across a backyard does a tenement no harm. If any such abuse as that feared by Mr. LEIGH did prevail, it could readily be met by legislative enactment. From his recommendation that the heavy tropical rainfall of this climate should be conveyed away through the house-drains it is clear Mr. LEIGH does not appreciate the main advantage of the Separate System viz.: the admissibility of small diameters for the house-drains. He attaches no importance to this, preferring to have in the sewage-conduits of the houses and of the streets diameters so large that they shall also be able to take in the heavy and deluging floods of Summer. Yet it is these large diameters, these capacions sizes, exposing so large a floor surface of sewer and so large a surface of sewage for evaporation to which we attribute the sluggish flow in the east and west street sewers and the consequent undue exhalation of noxious air from them. Also in respect of the objection to surface-gutters I should not forget to repeat here that Mr. COOPER's scheme does provide for the admission into the house-drain of a sufficient quantity of the rainfall,-and that is only the excess which it is proposed to convey away in the surface-gutters. This judicious arrangement while on the one hand providing the house-drain with a sufficient volume of rain water,will so restrict that volume as to enable it to be carried off -by means of pipes of small diameter.
8. Mr. LEIGH's second reason for objecting to the Separate System is that the scheme divides the City into four drainage districts (page 4* of Mr. LEIGH's letter). I am not sure that I have seized the grounds or reasons of this objection quite correctly as the indictment is so rambling that it is difficult to follow the argu- ments, but I understand Mr. LEIGH to mean that he would prefer six drainage districts instead as shewn in his map, the out-falls being placed at points marked L. 1, L. 2, L. 3, L. 4, L. 5, and L. 6. Mr. COOPER'S contem- plated division of the City into four separate drainage areas is in accordance with the natural configuration of the hill-slope and of the spurs and ravines that intersect those areas. The division is a natural division governed purely by the topography of the ground and the gradients of the streets. Under this arrangement the town sewage will be conveyed by easy inclines to certain points of out-fall away from the more populous centres of Victoria and discharged where the tidal current will soonest disperse it. The proposed inclines will be nowhere so flat as to incur the risk of undue deposits of silt in the pipe-sewers, more especially looking to the volume of descending sewage from the upper levels which will always maintain the flow through the lower town at a speed sufficient to be self-cleansing. In this respect Mr. LEIGH'S Combined System proposes the creation of new main drains running straight down the hill on steep inclines ranging from about one in four to one in ten, but this alternative is objectionable if only because it makes it difficult with such steep inclines to regulate and control the escape of the gases generated in such sewers,—a difficulty that is not lessened by the necessarily large sizes to which these conduits would have to be built since Mr. LEIGH would destine them also for the
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