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THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL, 



[ May, 



PROCEEDINGS OF SCIENTIFIC SOCIETIES. 



INSTITUTION OF CIVIL ENGINEERS. 



March 27 and April 3.— William Cubitt, Esq., V.P., in the Chair. 

 The paper read was a "Description of the Groynes formed on the South 

 Rocks, the site of the new docks at Sunderland." By Mr. W. Brow.ne, 

 Assoc. Inst. C.E. 



These groynes have heen erected for the purpose of retaining the de- 

 posited materials excavated from the new doclis, and of arresting the sand 

 and shingle which naturally travel southward, in order to form a barrier 

 heach, that should cfffctually exclude the sea from beyond a given line. 

 The three first, whose lengths varied from 326 feet to 358 feet, were erected 

 at a height above ordinary high-water mark of 2 ft. 6 in. and 10 feet at the 

 seaward and inner ends respectively. The exterior was composed of ashlar 

 work ; the interior partly of the excavated magnesian limestone, and partly 

 of rubble set in mortar; the batter of the north sides was two and a half 

 inches to a foot, that of the south sides one to one, and the crest was formed 

 into an arch, with a radius of 5 ft. 6 in. The four other groynes were con- 

 structed of a different form, in consequence of those first erected not retain- 

 ing the deposited excavations, and accumulating other materials as was de- 

 sirable, and from their having been injured by the sea during a heavy storm 

 which occurred at the time of the equinoctial tides during the spring of 

 1848, when a breach was made in the first and third groynes, and at the 

 same time some of the stones in the second groyne were loosened; these 

 effects were produced at about the same point in each, namely, the intersec- 

 tion of the inclination of the groyne with the line of ordinary high-water 

 mark ; and it was found, from observation, that the momentum of the 

 waves was greatest at about the time of high water. The sides of these 

 groynes were semi-cycloidal, each being generated by a circle of 12 ft. 9 in. in 

 diameter, and uniting at the apex ; the seaward and inner ends are respec- 

 tively 7 feet and 10 feet above ordinary high-waler mark, and their lengths 

 varied from 510 feet to 579 feet. The foundations of these groynes consisted 

 of a course of freestone, laid at an average depth of 2 feet below the sur- 

 face ; the sides were also of coursed freestone, set header-and-stretcner al- 

 ternately, and the hearting of large sized rubble, closely packed, the vacan- 

 cies between it and the ashlar work being filled with small stones set in 

 Komau cement, so as to ensure a solid .bed ; at a depth of 6 feet below the 

 crest of the groyne, and resting upoi! the rubble hearting, coursed ashlar was 

 introduced, and carried as near to the crest as possible, the vacancy being 

 filled with small rubble and Roman cement. The constructioji of these 

 groynes commenced at the seaward point, and they were placed at distances 

 of from 350 to 450 feet apart ; the quantity of material excavated and de- 

 posited between them was stated to amount already to 730,000 cubic yards ; 

 11 consisted partly of hard blue clay and partly of marly rock or soft mag- 

 nesian limestone, and the harrier beach formed hy them had completely 

 withstood all the gales which occurred during the wmters of 1817-8, and 

 1848-9. 



During the discussion, Mr. Murray explained very clearly his views in the 

 design for the docks, and for the direction of the groynes, and the various 

 works in the harbour for arresting the waves in their progress up the river. 

 The investigation of this subject elicited some very interesting remarks as to 

 the action of waves striking walls and groynes at various angles, when 

 instead of being reflected they were in part retained and guided along the 

 face. This was a peculiarity which, it vras, stated, should be taken advan- 

 tage of in hydraulic works. 



April 17. — Robert Stephenson, Esq., M.P., V.P., in the Chair. 

 The paper read was " On an application of certain Liquid Hydrocarbons 

 to Artificial Illumination." By Mr. C. B. Mansfield, B.A. 



The paper first noticed, that liquid hydrocarbons had heen comparatively 

 little used for the production of artificial light; and that in the instances in 

 which they had been applied, their liquidity, and not their evaporability, had 

 been turned to account. In the use of the common volatile oils, the excess 

 of carbon in their composition was the great difSculty ; but when that was 

 surmounted, that excess became an actual benefit. 



There were two methods of rendering this carbon efficient as " light 

 fuel," when advantage was taken of the volatility of the substances; one 

 was to cause the vapour, as it escaped from a jet, to mix rapidly with the 

 air. The other, to mix the vapour, before combustion, with other gaseous 

 matters containing less carbon. The adoption of the first of these was in- 

 stanced in Ilolliday's recently patented Naphtha Lamp. The second, con- 

 sisted of the new arrangement described in the paper. 



This principle was carried into practice in two ways. The first (which was 

 illustrated hy a lamp then burning on the table) was effected by mixing the 

 hydrocarbons with some other inflammable spirit containing very little car- 

 bon. The mixture was described as being made in certain definite propor- 

 tions, which ensured a perfectly white light, and from which any deviation 

 would result in a flame of inferior quality, — pale, if the hydrocarbon were 

 deficient, — smoky, if the mixture were poor in spirit. The ingredients most 

 accessible in this country were stated to be, wood, spirit, and a volatile oil 

 from coal naphtha, in the proportions of two-thirds of the former to one- 

 third of the latter. Alcohol and oil of turpentine had heen similarly used 

 on the continent, though the former was too dear for use in England. 



The other adaptation of the same principle, and that which it was the 

 chief object of the paper to describe, was the dilution of the hydrocarbon 

 vapours with permanent gases of inferior, or even of no illuminating powers. 

 That application might be called the napthalization of gas, or the gasiza- 

 tion of naphtha, according as its main object was to enhance the services of 

 the gas, or to utilise the liquid : the latter was the object of the new pro- 

 posal described in the paper. The farmer had been already accomplished by 

 preceding inventors. 



The first invention was that of Mr. Donovan in 1830, who proposed to 

 confer illuminating power on gases that were inflammable, but not lumini- 

 ferous, by charging them with the vapour of hydrocarbons; but from the 

 want of a sufficiently volatile fluid, he was compelled to have a reservoir 

 close to every burner. The next application was that of Mr. Lowe, who in- 

 creased the light obtained from coal gas by passing it over surfaces of naph- 

 tha. Mr. Beale's air light was then noticed; its object was to use hydro- 

 carbons for illumination, by passing a current of air through vessels contain, 

 iiig those liquids. There existed, however, the same obstacles to this plan 

 as to that of Mr. Donovan, viz., the heat required to evaporate the only 

 liquid hyilrocarbons then accessible. 



The paper represented that at length the difficulty had been solved, hy the 

 discovery of a liquid hydrocarbon, as volatile as spirits of wine, but contain- 

 ing sufficient carbon for the most perfect light, and obtainable in any quan- 

 tity. This hydrocarbon was procured from coal tar, and was called " Ben- 

 zole." Its volatility was such as to enable it to naphthalise atmospheric air 

 as effectually as ordinary naphtha did coal gas. 



The system proposed hy the author (which was illustrated in the room by 

 a working apparatus) consisted in conducting a stream of almost any gas, or 

 even of atmospheric air, through a reservoir charged with Benzole or some 

 other equally volatile hydrocarbon ; the gas or air so naphthalised being then 

 conducted like common coal gas through pipes to the burners. It was 

 stated, that the system was applicable on any scale, from the dimensions nf 

 town gas-works to the compass of a table-lamp. In the apparatus exhibited, 

 a small gas-holder, filled by a pair of bellows, supplied common air through 

 pipes. The gases formed by passing steam over red-hot coke would answer 

 well for this purpose, and it would depend on local circumstances whether 

 this mode of generating the current would be preferable to the expenditure 

 of the mechanical force necessary for driving atmospheric air through the 

 pipes. Pure oxygen charged with the vapour would explode on ignition ; 

 it was therefore suggested that this might prove a useful source of motive 

 force. It was, however, stated to he difficult to form an explosive mixture 

 of the vapour with common air. By decomposing water with the voltaic 

 battery, naphthalising the hydrogen with Benzole, and burning it with the 

 aid of the equivalently-liberated oxygen, a sin)ple hght of intense power 

 might be obtained. The system was shown to be a great simplification of 

 the ordinary system of gas lighting, as no retorts, refrigerators, purifiers, or 

 meters were required, and the products of combustion were as pure as those 

 from the finest wax. It was expected that the elegance of the material and 

 the simplicity of the apparatus would induce its introduction into buildings 

 and apartments where coal gas was not now considered admissible. 



The apparatus and conditions necessary for the success of the method 

 were, a flow of cheap gas, or of air, driven through pipes by any known 

 motive power, and a reservoir of the volatile spirit through wliich the main 

 pipe must pass in some convenient part of its course; these pipes and reser- 

 voirs being protected from the cold. It was stated, that though the liquid 

 did not require to be heated above the average temperature of the air, it was 

 liable to become cooled by its own evaporation, so as to require an artificial 

 supply of warmth. This was readily effected by causing a small jet of 

 flame of the gas itself to play upon the reservoir, and by a simple contriv- 

 ance, called a " Thermostat," by which the flame was shut off when neces- 

 sary, the temperature could be made self-regulating, so as never to rise above 

 or fall below a proper degree. The cooling due to the evaporation, would, 

 of course, be inversely proportionate to the quantity of liquid in the resir- 

 voir. If atmospheric air was used as the vehicle for the vapour, the jet- 

 holes in the burner, from which it escaped for combustion, must be sligliiiy 

 larger than those for coal gas. Some burneis, contrived for the purpose nf 

 accurately adjusting the size of the orifice to the quantity uf luminiferous 

 njatter escaping, were exhibited and described ; they were made so that hy 

 moving a part of the burner, any required quahty of flame, from lightlcss 

 blue to smoky, could be obtained, there being a medium point at which the 

 most perfect brilliancy was arrived at. The burners would answer equally 

 well for coal gas, though that material could not, even by them, be made 

 to evolve so white and pure a light as that from Benzole vapour. 



In conclusion, some data were given on which a calculation of price was 

 founded. It was stated, that a gallon of Benzole, of the degree of puriiy 

 requisite for the purpose, would cost about two shillings and sixpence; to 

 this, the expense of the air current and the interest of the original outlay 

 on apparatus was to be added. This the author presumed would not raise 

 the cost to more than four shillings for the consumption of the Benzole. U 

 was stated, that one ounce of that liquid would give a light equal to four 

 wax candles, of four to the pound, for one hour; or one gallon for about 

 one hundred and twenty hours. It was inferred, that a gallon of this mate- 

 rial was equivalent to about one thousand cubic feet of coal gas. 



Finally, for comparison with coal gas at a distance from the mines, it was 

 stated, that while to produce one thousand cubic feet of gas, at least two 

 hundred pounds of coal must be transported, one gallon of Benzole did not 



