1845.] 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



357 



account of leverage), not = effects and motion is prodnced, continually io 

 one direction. — Again you say, " The lowest point of a driving wheel 

 surely must not be considered the fulcrum of a lever, for then the centre of 

 the whole would move in the arc of a circle, whereaa its motion is recti- 

 lineal." — Now as the wheel is only a continuous lever, your stricture 

 seems to me to have more plausibility than weight, for tlie centre of the 

 wheel could only tend to move in the arc of a circle, the wheel's rotation 

 continually hearing it up, so as to move in a right line. 

 I am. Sir, 



Your obedient servant. 



J. G. S. 



In his first letter our correspondent proposed certain views on the theory 

 of Locomotive engines, from which we dissented, stating our reasons. 

 Hut, says our correspondent, in a second letter, I have repeatedly made 

 such and such an experiment which exactly proves my case. To this 

 we replied, by showing where we thought the experiment failed in analogy. 

 In the present letter this want of analogy is acknowledged, and at the 

 same lime stated to be 



.\re we to suppose the theory of that compliant nature, that both analogy 

 and the want of analogy in the illustrations alike confirm it .' 



The usual method of considering the centre of the wheel the fulcrum of 

 the lever seems the most simple aud satisfactory. If the lowest point of 

 the wheel be considered the axis about which the moments of the forces 

 on the spoke are to be equated, the reactions on the centre of the wheel 

 must be taken into account ; and these, we should think, would so com- 

 plicate the problem as to render it incapable of solution. Of course if the 

 solution be correct the result must be the same for either method of in- 

 vestigation. 



RAILWAY UOUXD PARIS. 



The Journal ((<•» Chemim de Fir gives a long account of the project to 

 encircle Paris by a railway, crossing and connecting all the existing lines 

 which radiate from the French metropolis. Me translate some of tiie 

 principal passages of the description. 



The necessity of an encircling line round Paris has been long felt ; the 

 loss of time occasioned in passing from one station to another, the expense 

 of carrying and warehousing goods, and the duties demanded octroi for in 

 entering Paris, render this railway indispensable. 



Three projects have been proposed : the first passes between the cir- 

 cuit-wall of the iictrvi and the continuous circuit of the fortifications ; the 

 second between the continuous circuit of fortification aud the detached 

 forts ; the third is exterior to the forts. 



Examined on their strategic merits, there is little difference between 

 these lines. A line connecting the detached forts would be of no more 

 service than one interior to the line of rircumvallaliou. It would be very 

 expensive, moreover, to carry the railway over heights, such as Mont 

 Valerien, Romainville, &CC., and long tunnels and inclined planes would be 

 required. 



The railway will not require a locomotive department, since it can be 

 supplied with engines by the lines w hich it unites ; aud as it will generally 

 serve for mere conveyance from one line to another — from the Northern 

 line, for instance, to that of Lyon — the traffic will be carried on by the 

 locomotives and carriages which arrive from the Northern line. The es- 

 tablishment of the railway round Paris will consist only in the construc- 

 tion of the road and laying down the rails. 



Examining the three projects which have been proposed, economically, 

 we have — 



First— An encircling line, connecting all the existing and projected 

 railways, and passing from the Hatignolles station of the Rouen line to the 

 Orleans line in the commune of Ivry, opposite Bercy, continuing thence 

 to Versailles railway, on the left bank of the Seine, and crossing the valley 

 of the Bievre, aud finally rejoining the Rouen railway, crossing the Seine 

 at Point-dn-Jour, and passing the Bois de Bologne. Length 19{ miles; 

 cost, £720,000. 



Second — By the line passing by the forts would be 37 miles ; cost 

 £1,040,000. 



Thirdly— The line bepond the forts— length 47 miles ; cost £920,000. 



The second and third lines, though Ihey make use of parts of existing 

 railways, would require a length of new line to be much greater than that 

 of the line interior to fortifications. Moreover, supposing either of the 

 two exterior lines adopted, it will be necessary to travel a certain distance 

 along the existing railway, which would be a source of constant acci- 

 dents. The traflic on these railways being always very great, tliere would 

 be great danger in using them for an additional line of traffic. In laying 

 down the interior line, it has been made a point that it should merely cross 

 the old lines. The object has been to connect the depots of merchandize. 

 VVe proceed to describe the manner in which this object is effected. 



The new line branches off' from the Rouen railway by means of a curve 

 of 1,300 feet radius opposite the workshops of the St. Germain line, and 

 crosses the site appropriated to the goods-depot of the Rouen line; it passes 

 beside the nhattuir of BatignoUes, and goes over the district road number 

 14, from Paris to C'lichy, at a short distance from the curtaiu 41 — 43 of the 

 fortifications. 



The line next crosses on a level the district road number 13, from Paris 

 to St. Owen, and turns round the declivities at the base of Montmartre, 

 with an accending gradient, which briu|is it to the level of tiie Belgic 

 railway. The royul ruad nambrr I, is crossed also on the level, about 

 2r,0 feet from La C'hapelle. 



Continuing its course within HOU feet uf the circuit wall, the line pro- 

 ceeds to the right-baud bridge uf the royal road Huniber 2, fruai Paris to 

 Haniborgli uu the Canal S,. Deuid, which itc^ls^eson a level. The canal 

 St. Onrcy will be crossed by a moveable bridge. There will be a tunnel 

 under Belleville 7,U20 feet lung to the road to Charonne. Again crossing 

 the district road 23, the line next reaches the Avenue de Vincenues. After 

 passing over the .A.venue de Bel-Air, the line reaches Fecamp, meets the 

 Seine at the Quai de Bercy, and recrosses the river to rejoin the Orleans 

 line. 



REGISTER OF NEW PATENTS. 



(l-'nder this head are piven abstructs of the speclljcittioni 

 putenu as tliey are enrolled. Any addltiuiial lidurmutiuii 

 may be obtaiued by apulyluu to Mr. LAXTON at the Office 



of ull the most importXj 

 e<iuired as to uuy patto. 

 of thi> JOURNAL.J 



MANUFACTURE OF SUGAR. 



AiGtsTCS WiLUAM Gadcsden, of Woburn-squ«re. in the county of Mid- 

 dlesex, gentleman, for '• Impromtenls in the maiiiifacturc o/ 5«5ar."— Granted 

 Jan. 16, 1845; Enrolled July K'^o. 



The object of this inrentiuu is to effect the evaporation of syrups, at a low 

 temperature, by cauking cylinders to revolve in llie syrups trliile being eva- 

 I orated ; which cylinders do not communicate any boat to llie syrups, but 

 being partially immersed therein, by simiily revolving tliey carry up the 

 syrup out of the general body of the liquid containeJ in the evaporating 

 vessels, and thus facilitate tlw evaporation. The cylinder is mounted on a 

 shaft, uhicli turns in bearings at the ends of ilie evaporating vessel, and re- 

 ceives motion from a steam engine, or other first mover. In cases nhere it is 

 desired to remove the steam Irom the apartment which contains the evaj^o- 

 rating vessel?, a cover may be placed over the top of each vessel and cylinder 

 »ith a pipe leading from it to a chimney or otlier outlet; care being taken to 

 maintain such a draft as nill causa the heated vapours to be qaickly removed 

 from the evaporating vessels. 



MANUFACTURE OF CHIjORINE. 



Robert Oxlanp, of Plymouth, in the county of Devon, checist, for " Jm - 

 /jrovements in the manufacture af Chlorine." — Granted Feb. 20, 1845; Enrolled 

 Aug. 1845. 



This invention is for a method of manufacturing chlorins by the decom- 

 position of hydrochloric acid by atmospheric air. The hydrochloric acid gas 

 and atmospheric air ore mixed in the proportion of one measure of the former 

 to two of the latter ; and the mixture passed through an air-tight furnace 

 kept at a bright red heat. The hydrochloric acid is preferred to be obtained 

 by decomposing common salt by sulphuric acid, in a furnace or retort, so 

 heated that the products of combustion do not mix «itli the acid gas evolved ; 

 and the acid gas should be dried (previous to mixing it «ith the airj, by pas- 

 sing it through a vessel filled with pieces of fire-brick, over which a small 

 stream oi sulphuric acid is constantly .flowing. The requisite supply of at- 

 mospheric air is kept up, by pumping it into an iron reservoir, furnished w ilh 

 a stop-cock or valve, for regulating the discharge of the air. The decom- 

 posing furnace, through which the mixture of hydrochloric acid and air is 

 passed, resembles an ordinary reverberatory furnace in form ; but it is so con- 

 structed as to admit of the fire passing over the arch and under the bed ; by 

 which means the furnace is heated without the fire passing into it. The fur- 

 nace is filled ttith pieces of porous pumice-stone ; and the gas and air enter 

 at the end farthest from the (ire, and pass out at the other end, through a 

 pipe at the upper part of the furnace. That part of the furnace nearest the 

 fire should be ke[.t at a bright red heat, by a fire acting externally ; the smoke 

 passing through flues, over the furnace into the chimney. 



The products resulting from the admission of hydrochloric acid and atmos- 

 pheric air into the decomposing furnace consist of chlorine, associated with 

 undecomposcd muriatic acid, and any excess of atmospheric air and nitrogen. 

 This mixture is cooled, by passing it tlirough a series of earthenware tubes 

 surrounded by water ; after which the hydrochloric acid is effectually sepa- 

 rated, bypassing the m'xturc through water ; and, finally , the chlorine is ob- 

 tained, and chloride of lime produced, by passing the residuary mixture into 

 the ordinary lime condenser, where the chlorine is absorbed, and the nitrogen 

 and atmospheric air remiining arc allowed to pass into the atmosphere. 



The patentee does not confine himsilf to the above details, so long as the 

 peculiar chaiacter of his invention be retained; but he claims the mode of 

 manufactming chlorine, by decomposing hydrochloric acid by atmospheric 



