104 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Mabch, 



tion, exhibits under the microscope, three distinct forms — namely, cubes (of 

 chloride of sodium), prisms, whicli lie distinct upon the other salts, and are 

 efflorescent, snlphate of soda); and small aggrejates of rhomboids inter- 

 mixed with small spherical particles, like pin-heads (carbonate of soda). The 

 residue of the evaporation of the water, after having been gradually raised 

 to a dull red heat, acquired a grey tint, and exhaled a slight odour of 

 burning azotized matter; and a piece of moistened turmeric paper held in the 

 evolved vapour, was transitorily reddened. 



Professor Ilrande had rmt been able to detect any potassa in this water; 

 and only a slight indication of the presence of a phosphate, in the preci- 

 pitate deposited by the water during boiling. 



Upon the whole, he is inclined to regard the following as a tolerably cor- 

 rect statement of the proximate saline components of this water : — 



Chloride of sndiiim 

 Siilptmte of Brtda. . 

 Curt)Oiiate of Boda 

 Carbonate of lime 

 Carbonate of magnesia 

 Silica 



Organic matter 

 Iron 

 Fhosptioric 



matter T 

 iric acid J 



Grains in the 

 Imperial gallon. 

 .. 10 53 

 .. 1:114 

 .. 8 63 

 . . 3-50 

 .. 1-50 

 . . 0-50 



.. Traces. 



The specific gravity of the water at 55°i3 10007. Its gaseotis contents he 

 has not ascertained. 



Mr. Grande concluded bis paper by giving a short comparative table, of 

 the relative quantity of solid matter contained in river and spring waters as 

 have been carefully analysed. The wells which are termed deep, derive their 

 water from the strata below the blue clay, and some of them penetrate into 

 the chalk ; those termed shallow, are supplied from the strata above the 

 blue clay. This is the case with most of the common London wells, which, 

 however, are often steined to a considerable depth in the clay, for the pur- 

 pose of forming a reservoir. 



Solid matter 

 in imp. gallon. 

 Thames at Greenwich .. .. .. .. 2"'9 



„ London .. .. .. .. 28*0 



„ Westn'inster .. .. .. .. 24"6 



„ Brentlord .. .. ,, .. 19'2 



„ Twickenham .. .. . .. 224 



,, Teddington .. .. .. .. ]7'4 



Average of the Tbaoi«s between Teddington and Greenwich 23-2 

 New River .. .. ,. .. 19-2 



Colne.. .. .. .. .. 21-3 



Lea .. .. .. .. . .. 23-7 



Ravensboiirnc, at Deptford .. .. .. .. 200 



Comb* and Uelalield's brewery. Long Acre; deep well .. 5H-8 



Apothecaries* Hall, Blatkfriara .. ,, .. 45-0 



Nottlng-hill .. .. .. „ .. CO-S 



Roval Mint . .. .. ,, .. zl'^ 



Hampstead Waterworks .. .. ,, .. 40-0 



Berkeley-square.. .. .. ,, .. 60*0 



Tilbury Fort .. .. .. ,, .. 75-0 



Coding's brewery, Lambeth . . „ . . .'iO'O 



,. >, ,, .. .. shallow well 110 



More'B brewery. Old-street .. ,. deep well 389 



,, ,. ,, .. .. shallow well llOO 



Trafalgar-square fountains .. .. ., deep well 68 9 



Well in St. Paul's Churchyard .. .. .. /."i-o 



„ Brt-am's-builriings .. .. .. .. 115-0 



„ St. Giles, Holborn .. .. .. .. lo.'iM) 



,, St. Martin's, Charing. cross .. .. .. 95-0 



,, Po3tern-row, Tower .. ., .. 88*0 



Artesian well at Grenelle, Paris .. .. .. 9-86 



PROCEEDINGS OF SCIENTIFIC SOCIETIES. 



ROYAL INSTITUTE OF BRITISH ARCHITECTS- 



Jan. 21. — Earl De Grey, President, in the Chair. 



Earl De Grey informed the meeting that the Council, considering that 

 much important information was contained in the Report and Evidence on 

 Iron, rqually applicalilc to architectural as to engineering purposes, had 

 referred those volumes to the Committee on scientific experiments and 

 investigations, for the i)utpose of examining and reporting thereon. 



The President also communicated to the memliers, in reference to the 

 Commission for the Exhibition of Works of Industry of all Nations, in 

 1851, that he had been officially applied to, doubtless with the sanction of 

 her Majesty and Prince Albert, to be a member of that commission; but 

 that he had liein obliged to decline the honour on account of his health not 

 permitting him to devote that .".ttcntion, which would be required by the 

 probalily arduous duties of that commission. His lordship had no doubt, 

 that the profession would be adequately represented by Mr. Barry, a fellow 

 of the Institute, who had been appointed on the commission. 



Mr. DKLLAAfY, V.P., called the attention to an invention by Mr. Thomas 

 Melling, by which the sashes of a window, instead of being lowered and 

 raised, as at present, by lines, weights, and pulleys, acted by means of a rack, 

 so that one sash served as a counterpoise to the other. Some observations 

 were made thereon by the President and Members, and Mr. Melling was 



advised to render his useful invention still more practically available, by 

 enabling only one sash to be opened at a time, instead of both at once, as 

 requisite according to his present method. 



A paper by Mr. Roberts, Fellow, was read, '^ On Ike Arrangements and 

 Construction of the Dwellings of the Labouring Classes,** which will be given 

 iu full next month. 



INSTITUTION OF CIVIL ENGINEERS. 



Jan. 29. — William Cdbitt, Esq., President, in the Chair. 



The discussion was renewed on the Rev. J. C. Cldtterbuck's paper 

 " On the Alienations and Depressions in the Chalk Water Level under 

 London." 



It was contended, that the water in the upper districts of the chalk accu- 

 mulated in a proportion increasing with the distance from the river or vent, 

 and fell off, in a corresponding ratio, during its periodical exhaustion, which 

 usually took place between April and November of each year. This alter- 

 nation of level, which in the upper districts exceeded fifty feet in perpendi- 

 cular height, would be represented by a line from the lowest vent, rising at 

 an angle to the highest point saturated with infiltrated water. This had 

 been proved by constant observation on wells, at given periods, throughout 

 a certain district; all the springs forming the river proceeded from that 

 source. From these and other positions it was argued, that if water be 

 discharged from a shaft in the chalk, by a power not capable of entirely 

 exhausting it, the rapidity of the reduction of the level would gradually 

 decrease, until it was exactly balanced by that of the supply. This would 

 naturally produce a gradually-extending depression of the water in the strata 

 for some distance around ; and it was shown to have been the effect pro- 

 duced, by pumping from an experimental well in Bushey Meadows, in 

 August and September, 1840. 



It was urged, that the real question to he determined was, whether a 

 supply of water for Loudon could be obtained from the deep springs in 

 the sand or chalk. Sections and diagrams were exhibited, to show, by the 

 former, that the supposed basin under London, was not as had been shown 

 by geologists; and by the latter, that from July, 1837, to December, 1849, 

 there had been a gradual depression of full fifty feet in the water of the 

 sand-springs under London; and iu consequence of this serious action, 

 several of the wells had become tidal in some localities, and the water was 

 rendered saline. 



The Railway Board. — The attention of the members was directed to a 

 serious case of legislative interference, whereby the free exercise of the pro- 

 fessional skill of the Institution was now unwarrantably trammelled, and the 

 pulilic service mati'rially interfered with. The introduction of wrought iron 

 instead of cast iron, into railway bridges, was a recent invention of great 

 value, and of which the most celebrated examples were the Cf)nway and 

 Britannia bridges. The same executive authority which had pronounced the 

 erection of these two bridges to be impracticable, had recently declared, that 

 a railway bridge constructed on a similar principle, and of identical mate- 

 rials, was insufficient iu strength, although it was much stronger, in propor- 

 tion to its possible load, tlian eillier the Conway or the Britannia, and 

 infinitely stronger than any of the cast iron girder bridges which had for 

 years .idequately performed the public service, and had been by the same 

 authority pronounced to he perfectly safe. The public had thus already been 

 for a month deprived of the use of an important line of railway, by the appli- 

 cation of an antiquated formula to a modern invention. For these coL^ent 

 reasons, it was considered that the members had a right to request the inter- 

 ference of tlie Council, on the behalf of the profession at largi;; and they 

 were urged to take such steps as appeared desirable for allowing the free 

 developuient of engineering talent ; and in the words of the Report of a 

 recent Royal Commission, removing from " a subject yet so novel and so 

 rapidly progressive any legislative enactments, with respect to the forms and 

 proportions of the iron structures" of railways, wbicli could not fail to be 

 " highly inexpedient."— This proposition was received with acclarnalion. 



Mr. Evan Hopkins's great Geological Sections of the Three Kranches of 

 the Andes were exhibited in the library. They showed about 260 miles from 

 west to east, from Cboeo to the River Meta, iu the eastern flanks of the 

 eastern branch of the Andes. 



Feb. 5. — James Simpson, Esq., V.P., in the Chair. 



The discussion was renewed on the Rev. Mr. Clutterbuck'r paper, and 

 was continued throughout the meeting, so that no original communication 

 could be read. 



It was contended, that the area of the chalk district, subject to infiltra- 

 tion, for the supply of the springs and streams uniting in the basin of the 

 Colne, could not possibly exceed the original published estimate of 113^ 

 square miles, and that the proportion of water filtrating through, for that 

 purpose, was much less than bad ever hitherto been estimated, inasmuch as 

 records by Mr. Dickinson's gauge was to u much greater amount than 

 those atfiirderl by the gauges kept by other experimenters. 



It was also contended, that the original position assumed in the paper, 

 had not been weakened by the subsequent discussion; that the observations 

 of the chemists bad tended to confirm the statement of the probability of 



