Page:The Building News and Engineering Journal, Volume 22, 1872.djvu/162

 146 THE BUILDING NEWS. Fes. 23, 1872. SSS rvws?vO_—lrlrlllnnNnntttttttt SS ee THAMES SEWERAGE COMMISSION, N considering Mr. Bazalgette’sscheme for draining the towns of the Thames valley lying between London and Windsor, we said that he himself had estimated the cost of com- pletely separating the rainfall from the sewage at from ten to twelve millions of money for the then population of London, from which we deduced a cost of £4 per head of the popu- jJation, and said that might be—and certainly is—more than the same work would cost in country towns. Let us make even more than a liberal allowance, and say thatit would cost half as much in these towns, or £2 per head of the population. That we will call the first item. © Mr. Bazalgette’s estimate of the cost of the proposed scheme, for main intercepting sewers, pumping stations, and land to be irrigated, is £630,000 for a population of 300,000, or about £2 per head of the present population. This is the second item. Tn addition to these main intercepting sewers, outfall sewers would have to be made to convey the sewage of the towns to them. The existing state of things in the towns to be dealt with varies much. In some the sewerage has been completed, haying its out- fallin the river or other watercourse, and in these the additional work will be that re- quired to extend the outfalls to the inter- cepting sewers. These have been, of course, brought within as short a distance of the towns as the levels and the contemplated outlay would allow. But they are in many eases at a very considerable distance from the towns, and, although the cost of proper sewers for those towns that are altogether at present un-sewered must not be thrown upon this scheme—because in any case proper sewerage will be necessary—yet there will be some considerable expense, even to those towns that are already sewered, in connecting the seyeral outfalls with the proposed inter- eepting sewers. Now we have no desire to represent Mr. Bazalgette’s estimate of £630,000 for 300,000 people as insufficient. We have no means of judging whether it is so or not, and no one can know whether it is so or not by the plans and statement put forth, assisted even by recent letters from Mr. Bazalgette to the Times on this subject; but assuming that a slight increase in his estimate were justifiable on grounds ofcommon experience, and taking into account the cost of extending the outfall Sewers so as to convey the sewage to the in- tercepting sewers, as we have already mentioned, it might not be an unreasonable estimate to say that the two together would probably be about 10s. per head of the population. We come then to this con- clusion, that under ifem 1 the cost would be £2 per head; under item 2, £2 per head, and under item 3, 10s. per head, making the cost of the scheme to every town on an aver- age £4 10s. per head of the population. Can it be said that we have over-estimated the cost of a separate system of drains to carry off all the rain-water by taking half Mr. Bazalgette’s own estimate for London, or at the rate of £2 per head? If so, let us put it at 30s. per head, and the case will then stand thus :— Item 1 is Qa apc eral £110 0 tem 2 Z 0 0 0 Four pounds per head on a population of 300,000 amounts to £1,200,000, the yearly interest on which, at the rate it is assumed that it can be borrowed at—viz., 52 per cent., and one-sixtieth part paid off annually, amounts to £66,500. The pumping, main- tenance, and management, as estimated by Mr. Bazalgette, would cost £6,000, making a total of £72,500; and for this outlay it is estimated that the yearly return from the irrigated land, estimated at £8 per acre on 3,000 acres, would be £24,000, leaving £48,000 per annum to be made up by rates upon pro- perty. The net annual rateable value is stated to be £1,000,000; therefore it would require arate of 11:64 pence in the pound, or very nearly one shilling, to cover the first year's expenditure, or three times the rate that is set down—yvyiz., 4d. And, however much this may seem to differ from the estimate put for- ward by so very high an authority, we challenge, on a reconsideration of the estimate we have given above, a comparison between the two. But there is a further consideration: £8 per acre is claimed as returnable from the land to be irrigated. That, however, is very doubtful indeed, for this reason, to begin with: the quantity of liquid sewage is limited to the mere house-drainage, and the soil selected to be irrigated with it is sand and gravel. Now, if land is to be truly irri- gated with sewage, and be anything more than a mere filter—in which case it were better to say so at once, and not expect any return—it must flow over the surface from the carriers, and there must be a suffi- cient quantity of liquid to enable it to do so; but in this case that is prevented in two ways, viz., a minimum of liquid and a maximum of absorbing power of the soil, and for this reason we say that the return of £8 an acre is very doubtful indeed, and that it is much more likely that the adoption of the scheme would entail a perpetual rate of 1s. in the pound overthe whole district. We are even now supposing, with the promoters, that the money can be borrowed for 60 years at the rate of 32 per cent. If that cannot be done, of course the rate would be still greater. The light in which to look at this scheme is that it will cost £4 per head of the population to begin with, one-third of which may, if the expectations of the promoters should be realised, be returned. In this way it may be ascertained in any town in whien the population is known what the probable cost of the scheme will be. It is not always a correct mode of reason- ing to take an average of things, but in this case it is strictly so, for if one town suffers less, another must suffer more, and the com- bination of the whole number of towns is the essence of the scheme. It will not be per- mitted to pick and choose this town and that for exemption, but all must join. By excluding all rain-water from the sewers the quantity of sewage would be reduced to the quantity of water used. This would, probably, not be more than twenty gallons per head per day on an average of these towns. In London about thirty gallons are used; but in Manchester, where large quan- tities are used for trades purposes, the supply, including water for trades purposes, is only about twenty-two gallons per head per day ; while at Norwich, where also a considerable quantity is used for trades, the supply is less than twenty gallons ; therefore, looking at the character of these townsin the Thames Valley, where but small quantities of water are required for trades purposes, 20 gallons per head per day is afull estimate. It is certain that the quantity at present used is much less than that, a large portion of the supply being procured by hand pumps from wells, but it is but fair to assume that ultimately all the towns may be supplied with something like 20 gallons per head per day. Taking that quantity, the quantity of sewage avail- able for the irrigation of the 3,000 acres of sand land will be ultimately about 3,250 tons per aere per annum, although much less than that until every place is supplied with the full quantity of 20 gallons per head per day. But from repeated trials and experiments by various Commissions appointed to investigate this subject, it has been found that the best results are produced by a quantity of about 5,000 tons per acre per annum, when the land contains a portion of clay. On some portions of the Lodge Farm, at Barking, consisting of gravel, from 12,000 to 15,000 tons have been applied, and on some other portions, con- sisting of strong land, 4,000 tons. At Carlisle the quantity applied is from 8,000 to 9,000 tons; at Warwick, 6,372; at Rugby, 5,065; at Bedford, 7,520, and at Bury, 9,400. In what light, then does this quantity of 5,250 appear when we recollect that the land to which it is to be applied is nearly a pure sand ? It is true that Mr. Hope applies nearly this very quantity to the irrigation of his farm at Romford, but the character of the land is different in the two places; and, in fine, it does not appear at all certain that so small a quantity of sewage can be made to cover so large an area of sand land. ee CRITICAL NOTES ON GREAT ITALIAN ARCHITECTS.—VIL. By J. B. Wanrtnc. A TRIO OF PAINTERS WHO PRACTISED ARCHI- TECTURE. E haye pointed out, in the lives of the great Italian architects already noticed, that it was part of their education to be prac- tically acquainted with all the arts. There is not one of them, probably, who was not an accomplished draughtsman—not in our or- dinary meaning of the word when applied to architects, when it means a merely manual faci- lity of making pen and ink, or penciland colour, sketches and drawings of buildings and orna- ment. A draughtsman in Italy of the Revival meant a man who was master of figure-draw- ing: the study of the nude or the antique was general. Peruzzi, for example, drew the figure as only a master can; and Brunel- leschi’s nude figure of Jesus is celebrated. It is no doubt a most important study, even for the architect, neglecting which he cannot - be considered as duly educated; for if he fails to see and admire the subtle delicacy of curyes in the human figure, so will he fail to see and admire the almost equally subtle beauties of contour in various mouldings and in ornament; and if he does not appreciate the justness of proportion in the human figure, neither can he do so in respect to buildings. In both cases there are indisput- able and standard rules of proportion with which all artists should be acquainted. f We have seen that Vasari expressly attri- butes Peruzzi’s excellence as a designer in architecture to his knowledge of drawing generally, and there can be no doubt that his remark is founded on fact and reason. But we must admit that a wide difference exists between the great architects we write of in the past and those we see and hear of in the present day. Art was everything at that time, and was obtained by early, prolonged, and varied study. The architect of the present day is as much a builder or trades- man as an artist. Prices and materials are objects of his attention, and he must look generally into minutiz of business. This, as we have seen, was not so in Italy during the fifteenth and sixteenth centuries. The architectural designer made a model of the building as he meant it to be, and the carry- ing it out practically was placed, as a rule, in other hands. Thus the business of the archi- tect was comparatively easy when once he knew the elements of architectural design ; and thus it was that we find even great painters, who must have been continually employed in’ their special art, yet giving designs for buildings, and of these we select three eminent artists who have left behind them examples of their ability as architects: these are Michael Angelo, Raphael, and Giulio Romano. We will take Michael Angelo first, for the period of his labours extends to a period before and after that of the others. Born in 1474, and dying in 1563, he may be said to haye lived through the greatest epoch of the revival of ancient art, to have seen it at its zenith, and to have beheld the first symptoms of its decline, to which, indeed, his own in- dividual character gave a decided impetus.