84 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Feb. 17, 



The Art of Land Surveying for the use of Schools. By John Quested. 

 London : Uelfe and Fletcher, 1843. 



This liltle manna! is for the nse of schools, to which purpose it seems well 

 adapted ; we must, however, regret that so many books are accumulated on 

 this subject with so few new results. 



PROCEEDINGS OF SCIENTIFIC SOCIETIES. 



INSTITUTION OF CIVIL ENGINEERS. 

 Fell. 13. — Gkokge Rennie, Esq. in the Chair. 



A paper hy Mr. J. Grantham described a series of experiments on an iron 

 vessel called the Liverpool Screw. This boat w.is 0() ft. long, 12 ft. 6 in. 

 beam, and liad 3ft. 9 in. draught of water; she was propelled by two high- 

 pressure oscillating engines witli cylinders 13 in. diameter, and 18 in. stroke; 

 the pressure of the steam in the boiler varied from 50 lb. to 601b. per square 

 inch, and it was cut off at one-fourth of the length of stroke, working the 

 remainder hy expansion; the nominal power was 20 horses, but it did not 

 really exceed 18^ horses. The cylinders were placed diagonally, with both 

 the piston rods working on the same crank, the driving shaft being beneath 

 the cylinders, and running direct to the propeller without the intervention 

 of either gearing or bands. The screw propeller was enlarged three times, 

 and at last was left at 5 ft. 4 in. diameter by 20 in. in length ; it was set out 

 with a pitcli expanding from 10 to lift, on Woodcroft's plan ; it was made 

 of wrought iron, with four short arms witli broad shovel ends, whose united 

 area was 16 square feet, 13 ft. only of it being immersed, as some portion 

 of the arms was constantly above the water; the angle of the centre of the 

 float was 45°; the speed of the propeller was generally 95 revolutions per 

 minute. With these dimensions the speed attained was described as lOi 

 statute miles per hour. The amount of " slip " of the screw in the water, 

 as ascertained by Massey's log, was stated not to exceed 5 per cent. Several 

 experiments were detailed, which showed tliat there was not more tendency 

 to "list" or to turn round by the action of the screw, than with paddle- 

 wheels, and the vessel was said to have excelled all the other steamers of 

 the port of Liverpool in towing out vessels in a rough sea. 



Designs were submitted on this principle for a steam frigate and for large 

 steamers working wiih oscillating cylinders direct upon the main shaft. 



In the discussion which ensued, the various forms and modifications of 

 screw propellers, and their relative merits were very ably treated by a number 

 of speakers. 



Mr. Uennie gave a sketch of the introduction of a kind of screw used by 

 Mr. S. Brown with his gas engine, which was tried on the Thames ; the 

 more successful attempt of Mr. Smith, and the buihling of the Archimedes 

 and other vessels ; he mentioned also (he claims of Mr. Sauvase, of Bou- 

 logne, to the invention, and his being recently rewarded by the King of the 

 French. Mr. Rennie entered largely into the theory of the forms of the pro- 

 pellers, and in this he was followed by Mr. Farey, Mr. Galloway, Mr. Sa- 

 muda, and others, and Monsieur Normand, of Havre, who is celebrated for 

 giving such superior forms to the vessels built by iiira ; he gave a slight 

 sketch of the Napoleon French frigate, in which he eulogized the engines 

 constructed by Mr. Barnes and the general result obtained with the vessel, 

 hut it appeared that the speed was not superior to what had been obtained 

 with paddle wheels. 



Pump I'nlves. — A model was exhibited by permission of Sir II. T. De la 

 Bcche, from the Museum of Economic Geology, showing all the kinds of 

 valves used in the pumps for draining the Cornish mines, and the merits and 

 defects of the various kinds were very ably explained and commented upon 

 by Mr. Jordan, under whose directions the model was constructed. Mr. 

 John Taylor gave an historical sketch of the introduction of the various 

 improvements, the causes which led to them, and the effects they had pro- 

 duced ; the length of the discussion on the screw propeller left so liltle time 

 for the subject of the valves that it was announced to be renewed at the 

 next meeting, on Tuesday, February 20th. 



THE ROYAL SCOTTISH SOCIETY OF ARTS. 



January 22. — Professor Traill, M.D., F.R.S.E., President in the chair. 



The following communications were made : — 



1. Sir George S. Mackenzie, Bart., exhibited three elegant specimens of 

 Mr. Cheverton's work in ivory, in a difi'erent style from that formerly shown, 

 and communicated part of a letter from him. The subjects were the Mer- 

 cury and Pandora of Flaxman, and Morning and Night by Tborwaldsen. 

 These specimens were much admired. They can be executed at twenty 

 guineas, inclusive of the frame. Their effect, when viewed as semi-transpa- 

 rencies, is also very fine. 



2. A Ball and Socket Levelling Instrument, constructed by Mr. Aeie, for 

 Thomas Stevenson, Esq., C.E., and also an improved Portable Levelling 

 Instrument and Rod, were exhibited. Communicated hy David Steven- 



son, Esq., F.R.S.S.A., civil engineer. In this ball and socket spirit-level, 

 designed by Mr. Thomas Stevenson, civil engineer, the first peculiarity is the 

 substitution of a small circular level fixed upon the upper side of the tube for 

 facilitating the setting of the instrument, instead of the delicate cross level at 

 present in use. But the principal advantage of Mr. T. Stevenson's improve- 

 ment consists in the combination of the ball and socket motion for the first 

 setting, previous to the application of the parallel plate screws for the final 

 adjustment. The ball and socket was long in use, but for about half a century 

 it has been almost entirely discarded, and the parallel plate-screws substituted. 

 In the level exhibited to tne Society, the hall and socket has been restored, 

 and the parallel plate screws retained, so that by this union the advantages 

 peculiar to both systems have been attained. The person using this instru- 

 ment is in consequence rendered quite independent of the rugged nature of 

 the ground on which it is set, or the inclination of the telescope to the hori- 

 zon, as by looking first at the small circular level, he can in an instant bring 

 it nearly right hy means of the ball and socket, after which, a slight touch of 

 the p,iral!el plate screws perfects the adjustment. In this way the oljserver 

 can set his instrument with exactly the same rapidity and ease on a steep 

 slope iis on level ground, and is enabled to proceed with equal facility at such 

 rugged stations as would in the instrument now in common use altogether 

 exceed the range of the parallel plate screws. The practical surveyor will see 

 the great saving of time and trouble resulting from the use of Mr. Stevenson's 

 instrument. 



Mr. David Stevenson also showed s. portable level and rod, constructed to 

 his directions, by Mr. Adie. With nearly the same accuracy as the large 

 levels, this instrument possesses the advantage of much greater portability. 

 It combines a telescope 10 inches long, a compass, and a level, and is packed 

 in a flat leathern case measuring about 6 in. by 2 J in., rendering it very con- 

 venient for perarabnlatory surveying, for which it was made. It rests on a 

 tripod, which is also very portable. The levelling rod accompanying this 

 instrument, when closed, forms a round staff 3ft. Gin. long, which is cut 

 longitudinally through the centre. The two parts are hinged at one ex- 

 tremity, and when the rod is to be used they are opened and fixed hy a spring. 

 The scale is marked on the flat side, and when the staff is closed the figures 

 are protected from injury. 



3. (Parti.) Observations on, and Improvements proposed in the Ventilating 

 and Warming of Factories; with Remarks upon the essential importance of 

 pure air for the preservation of the health of those engaged in employments 

 carried on in a confined atmosphere, whatever be its temperature. By Robert 

 Ritchie, Esq., Civil Engineer, Edinburgh. The first part of the paper gave a 

 shortaccount of the different methods which had been employed in heating fac- 

 tories by steam pipes, as now nearly universally adopted, describing the man- 

 ner in which these were generally arranged ; and concluded with a short 

 description of improved ventilating arrangements which had been adopted in 

 some extensive factories. 



.SECOND GENERAL MEETING OF THE ARCHITECTS AND 

 ENGINEERS OF GERMANY. 



Held at Bamberg on the 8th, 9th. & lOlh of September. 1843. 



Wt. find in the Allgtmeine Bauzeiiung an account of the second meeling of 

 the architects and engineers of Germany, which was last year held at Bam- 

 berg in Bavaria, on the 8ili, 9lh, and 10th of September. The first meeting 

 was held at Leipsic. The meeting at Bamberg was held in the public as- 

 sembly room, called the Concordia. Arouhd the hall were exhibited the ar- 

 chitectural drawings sent to the meeting. 



Sep. Stii.—A public breakfast was held early in the morning. The rest of 

 the morning was employed in the examination of the catbeilral and other 

 curiosities of the city. At 11 t!ie meeting commenced, when llerr Barlet 

 welcomed the memliers to Bainberg in the name of the citizens. To this 

 speech Dr. Puttrich replied in the name of the members. 

 Dr. PcTTRtcn then took the chair. 



Professor Stier read a paper containing some remarks on the present state 

 of architecture and its early condition. 



Professor M'iessenfeld, of Prague, then communicated a plan for a third 

 bridge at Prague, of wood, and of large span, to cross the river Moldau. The 

 dfsign was by a carpenter of Prague, fur a colossal structure of wood and 

 other materials, partly on the suspension principle, the span of w hich is pro- 

 posed to be ol 600 feet. A limg discussion ensuid on this, but without any 

 determinate conclusion being come to as to its practicability. 



Sep. 9. — Professor .Stier opened the meeting with a pai)er on architecture, 

 on rectilinear and arched or curved architecture, and their prospects in the 

 present day. 



Herr C. W. Hoffmann, architect, of Berlin, made a communication on the 

 discovery by Khrenberg of inlusorial earth. 



Herr KRAFfT, C.E., of .Stettin, read a paper on btton or concrete founda- 

 tions, as ai)plicd by lleir Nechaus, C.li., on the Slettin Railway along the 

 Oder, where it had been nrtessary to build a collVr-dam 30 ft. to 35ft. deep, 

 the depth of water being upwards of 20ft. Herr Kraflt stnmgly recom- 

 mended the use of concrete for such purposes. la the present instance a 



