Nov. 9, I&88.] 



SCIENTIFIC NEWS. 



493 



have influence in the production of such a result. If, he continued, 

 " this high rate of infantile mortality is to be reduced, more care — 

 at least in Queensland — will have to be taken in improving the 

 dwellings." The improvements suggested were in the direction of 

 increased size, and of improvement in the corrugated iron roof by 

 duplication with suitable intermediate packing so as to diminish 

 the extremes of heat and cold, which are permitted by the single 

 roof. Then the planting of trees to moderate the aridity of the air 

 was advocated, and it was pointed out that though sanitary science 

 can do little to mitigate the severity of climate, it ought at least to 

 guide the choice of healthy sites for habitation. The hygienic con- 

 ditions of country life were next touched upon, and the character- 

 istics of a favourable site were described. The question of milk 

 was next considered, and the value of substitutes referred to. 

 Simple measures for the reduction of the house-fly nuisance attested 

 by the author's experience, were given, as well as for other insect 

 pests. - The difficult questions of sewage and nightsoil disposal 

 were also treated of. Dr. Bancroft warmly invited the attention of 

 botanists to the problem of the cultivation of soil fertilised by sew- 

 age, when the fertilising agent so greatly exceeds the necessities of 

 the land itself, and he himself indicated some probably valuable 

 lines of cultivation. The vexed question of the mode of dissemi- 

 nation of typhoid came next for attention. The principles laid 

 down may be thus summarised. The European idea of the spread 

 of typhoid, almost entirely by sewage infection of drinking water, 

 comes far short of the facts as we know them here. 



Section J. — Engineering and Architecture. 

 This section was presided over by Professor Kerney, of Melbourne. 

 It was opened by a paper on The Deep Drainage System of 

 Adelaide: Its Results and Mistakes, by the Hon. Dr. Allan 

 Campbell, M.L.C., Adelaide. The paper elicited a considerable 

 discussion, as the question is one in which the public interest in 

 Sydney and Melbourne at this moment is deeply centered. Pro- 

 fessor Warren ; Mr. Jones, hydraulic engineer ; Hon. Dr. Garran, 

 M.L.C. ; Mr. Helmsley, and otheis, took part in the debate. In 

 the maj' rity of instances the views put forward by the writer were 

 endorsed by the speakers. The suitable situation of Adelaide for 

 economical drainage was pointed out, its previous unsanitary state 

 detai'ed, and the assertion was made that it is now the cleanest, and 

 has the lowest death-rate of any of the Australian cities. Mortality 

 returns were given to show this. A description, from an engineer- 

 ing point of view, was given of the system, and also a detailed account 

 of the result when the system was first brought into operation. It 

 was here where the writer pointed out the rock on which the system 

 split, and which had led not a few sensible people in Adelaide to 

 declare, in that new country, a great practical blunder had beer, com- 

 mitted. The ventilation of the street sewers was so imperfect that 

 a greater nuisance appeared to have been created than the one the 

 system was intended to remove. It was pointed out that the use of 

 the " boundary " or " disconnecter " trap divided the system, so far 

 as its ventilation was concerned, into two parts — the one next the 

 street sewers unventilated, the other next the dwelling-houses 

 ventilated by what the writer called the principle of through venti- 

 lation. The latter had never given rise to any annoyance, while the 

 former was an unmitigated nuisance. Improvements on this portion 

 of the system had to be made, and the principle of through ventila- 

 tion partially applied. The result had been so satisfactory that 

 Dr. Campbell claimed that the same principle should be applied 

 throughout, and the only means of doing this was to abandon the 

 use of this "disconnecter" or "boundary" trap. The object of 

 this trap is to bar the way of foul sewer air towards the dwelling- 

 house, but it was shown cleaily and comprehensively that barring 

 the way was simply creating a lodgment for foul air. The best thing 

 to do was to make sure that foul air would not be permitted to form, 

 but every instant would be swept out of the way. It was pointed 

 out that the sewers were small in size, they discharged their contents 

 with great ease and rapidity, and they were easily ventilated. It 

 was also shown that no pipe from the inside of any dwelling stood 

 in direct connection with any drain, but the flow from all pipes fell 

 into a receptacle or trap, which had on its drain side a ventilating 

 tube led high above the eaves of the house. By such means no 

 pressure could bear against the water seal of this trap. Join this 

 further fact to what has already been said, that periodical compul- 

 sory examinations of all house drains are made with the smoke test, 

 and it was contended that the danger which the "boundsry " trap 

 was employed to prevent could not actually exist. It wss urged 

 that we ought not to import conceptions derived from a system of 

 sewers such as had been employed in the old country and elsewhere. 

 We must view the new mode of construction scientifically, that is, 

 as it actually stands, losing sight of no factor in the system ; and if 

 we did so, the whole was simple and clear on the question of venti- 



lation. In closing an animated debate, Dr. Campbell quoted the 

 opinion of an engineer of some eminence (Julius W. Adams), who 

 advocated the ventilation of a sewerage system on the same lines as 

 he did, that all that was required was to "enable the sewers to 

 breathe and ventilate themselves." 



Section J. — Architecture and Engineering. 



Professor Kernot introduced the subject of waterways of culverts 

 and bridges. He remarked that the question was one of the highest 

 practical importance to the road and railway engineer. He quoted 

 a considerable number of rule; and formulae proposed by English, 

 American, Indian, and Victorian engineers, and gave his preference 

 to a modification of Colonel Dickens's rule. He showed that the 

 proposed rule co responded fairly well with a large number of success- 

 ful structures of long standing in New South Wales and Victoria, and 

 that the proportions that departed farthest from it on the side of 

 efficiency had coincided with the scenes of disastrous failure and 

 costly reconstruction. These cases were : — I. Bridgewater, Tas- 

 minia, 13 squire feet waterway to 2 I-Jrd square miles drainage 

 area. 2. Bendigo Creek, Sandhurst, Victoria, iqo square feet to 

 16 square miles. 3 Cootamundra, New South Wales, 53 square 

 feet to 20 square miles. 4. Plenty River, Victoria, 410 square feet 

 to 6o square miles. 5. Barwon River, Geelong, Victoria, 4,00a 

 square feet to 1,703 square miles. The rule given by Professor 

 Kernot required for the Bridgewater case about no square feet in- 

 stead of 13, for the Bendigo Creek rather over 303 instead of 190, 

 for Cootamundra 380 instead of 53, for Plenty River 860 instead of 

 440, and for the Barwon 10,000 instead of 4,000. On the other hand, 

 it agreed fairly well with numerous important bridges over the 

 Bendigo Creek, Moonee Ponds, Yarra, Saltwater River, and 

 Barwon in Victoria, that have been often tested by heavy floods 

 during the past 30 years, and have proved sufficient but not excessive ; 

 and also with the bridges at Bathurst and Wellington in New South 

 Wales. The paper was illustrated by large diagrams, and the 

 author concluded by requesting the members to send him particulars 

 of any cases of sufficient but not excessive waterways of old stand- 

 ing, also cases of notable failure, whereby further to confirm or, if 

 necessary, slightly modify the rule proposed by him. 



Mr. C. O. Burge read a paper on the Recent Progress in Sinking 

 Deep Foundations for Engineering Work-in the first place, with 

 the partial substiiution of iron for timber in pile work; several 

 instances were given of the use of screw piles on a large scale, and 

 of the failure of them ia many eases where they had not been used 

 with sufficient judgment. Their suitability for marine piers and 

 other similar structures was alluded to, and examples quoted. 

 Cylindrical foundations were noted, bo'.h of brick wells, of which 

 the use in India is universal, not only largely in the present day 

 for great railway bridges, but in ancient times by natives ; 

 and of iron cylinders, which, out of India, are the most 

 favoured methods of construction for works of the kind. 

 Several bridges in India, the new Tay bridge, double 

 cylinders at the Cape and elsewhere, were alluded to in this con- 

 nection, and the alternative of several small brick-wells or few 

 larger ones was adverted to, as forming a subject of protessional 

 differences of opinion in India. After describing a curious operation 

 witnessed by the author at Cawnpore, in destroying old well founda- 

 tions to make room for new ones, the paper proceeded to the con- 

 sideration of the pneumatic methods, both in cylinders and in 

 caissons. The St. Louis, Brooklyn, Forth, and Harlem bridges, 

 and one at Copenhagen, were briefly described as regards their 

 substructure, as well as the Eiffel tower in Paris, and the Delaware 

 Bay lighthouse, the latter, from its exposed position, being 

 a work of unexampled difficulty, all these having been founded by 

 means of the pneumatic process, but differing in detail ; these, of 

 course, being merely prominent instances of a system widely 

 adopted, especially on the Continent of Europe and in the United 

 States. Beyond the depth of about 100 ft. below water level, 

 which is the limit of the scope of the pneumatic process, mechanical 

 dredgers have to be used, and as the skin friction becomes in these 

 cases so great that the weight of the cylinder itself, even if reinforced 

 by all practicable temporary loading, is insufficient to sink it, the 

 design must be made so that the caisson, or cylinder, must carry its 

 own weight by loaded concrete partitions. 



A paper On Utilising Waste Underground Waters by Tunnelling 

 in the Hills, by Mr. T. Parker, C.E. , of Adelaide, was next read. 

 The author described the loss of water by evaporation, absorption, 

 and percolation, and suggested tunnelling to catch the latter, 

 especially in connection with the Adelaide water supply, the 

 advantages being extra purity of water, economy, no reservoirs 

 being required, and facility of extension. Professor Kernot re- 

 marked on the great waste of water, only 1 per cent, of the rainfall 

 reaching the sea from the western rivers. 



