1840.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



irs 



Iron Canal Boats in America. — The success of this class of boats in 

 England, with the arrival of the Iron Steamboat at New Orleans from Pitts- 

 burg, (of a very light draught of water, carrying a great cargo,) has led to the 

 oinnion that iron canal boats, if used on the Erie canal, would double its 

 capacity, and supersede the necessity of the enlargement. We trust that 

 some of our enterprising forwarders will try the experiment. We arc not 

 fully acquainted with the cost of these kind of boats, but have been informed, 

 tiiat it w ill not exceed fifty per cent, on the cost of tlie best Lalte boats. In 

 I'enn ylvania, witli their mixed line of canals and railroads IVoni Philadeljihia 

 to Pittsburg, they now use ii'on boats, divided iulo three parts. The iron 

 boat is carried into Market-street, Philadelphia, on the return of the cars, at 

 the Schuylkill canal they are hooked together, forming a complete boat, 

 which afterwards passes the Allegany-ridge, by ten inclined planes, when 

 they again take the canal and river, to reach Pittsburg. With this compli- 

 cated system, they compete with us successfully for the early spring trade. — 

 American Railroad Journal, 



Destruction of Wooden Bridges in America bv Ice. — The break- 

 ing up of the winter lias caused a recurrence of a specie of accident which is 

 far from being rare. M'e allude to the destruction of bridges by the com- 

 bined force of a swollen stream and immense masses of ice. The liability to 

 this lund of accident depends more upon the character of the stream nearer its 

 source than at the location of the bridge itself. A river of any considerable 

 size receiving the drainage of a large track of country, is of course apt to be 

 speedily swollen by a sudden and heavy fall of rain or rapid thaw, and as one 

 or the other of these circumstances are sure to accompany the breaking up 

 of the ice, such streams must present locations badly adapted to ordinary 

 wooden bridges. Shallow streams, from daming up the ice, are rather worse 

 than others in this respect, yet they are the most frequently crossed by these 

 insecure structures. Bridges of a more durable construction, if not built in 

 the most substantial manner, are likely to sutfer from the same cause, if the 

 water way has been too much diminished. The proper substitute in such 

 localities are sv^pension bridges of iron wire. These claim the preference of 

 all others, whether in regard to economy of first cost, or their superior 

 adaptation to the circumstances of the locality. Over a large portion of our 

 country the character of the streams is altogether more favourable to this 

 than any other species of structure. The example of the new bridge at Fair 

 Mount will, we hope, speedily be followed in many places. — American Rail- 

 road Journal. 



tfEW INVENTIONS, IMPROVEMENTS, «5c. 



Improved Mode of Making Bricks. — A correspondent of the /Ja/fa'oy 

 Times describes a simple method of making bricks adopted on the Great 

 Western Railway on Mr. James Bedborongh's contract at or near Marstou. 

 It is the invention of Mr. W. B. Pritchard, Esq., Civil Engineer of this Railway, 

 and late of the Chester and Crewe Railway, Ikt:., is as follows : — The clay, 

 only watered, is thrown into a common jnig mill (or mortar mill); there it is 

 ground in a similar manner to mortar; the bottom of the mill is divided into 

 four quarters, into which are grooves cut, and under which are placed four 

 moulds of the same kind as those in common use by hand-moulders. Two 

 boys are at the quarters taking the moulds out and placing others in ; and by a 

 peculiar knife at the bottoln of the mill, which presses the clay into the mould, 

 eight bricks are made every time the horse goes round, which is twice a mi- 

 nute ; and at that rate the horse can travel twenty miles iu twelve hours, thus 

 making 960 an hour, or 11,520 per day. The bricks made by this machine 

 are much heavier and sounder, and the clay much better tempered, than by 

 any other mode of manufacturing that I have ever witnessed ; and the saving 

 is 2s. 6d. per thousand, besides other advantages, &c. 



Moses Poole, Liucoln's-imi, improvements in apparatus applicable to 

 steam-boilurs , in order to render them more safe, Marcli 11. — The first im- 

 provement consists in a mode of applying to the boiler, as a species of safety 

 valve, a metallic plate or disc, which shall burst when the steam in the boiler 

 attains a certain degree of pressure, and thus relieve the boiler, which plate 

 may afterwards be replaced with a fresh one, without stopping tlie working of 

 the engines. To an aperture in any convenient part of the boiler is fixed a 

 curved tube, terminating in an enlargement or cup, having a ledge riuiuing 

 round the bottom for the safety disc to rest ujion. Upon the disc is laid a 

 ring, the edge of which is chamfered off, so as not to cut the disc, and this 

 ring is secured down firmly by another ring, which is screwed into the upper 

 part of the cup. The outer bend of the pipe contains water, both above and 

 below the disc, in order to maintain it at the same temperature on each side. 

 On any convenient part of the bent pipe, is fitted a cock, by closing which, 

 the connection of the cup with the boiler is shut off, and another disc may 

 then be replaced without stopping the operation of the engines. The second 

 improvement consists in the application of a steam whistle, to give notice 

 when the surface of the water in the boiler is below a certain point. The 

 whistle is of the ordinary kind, and the aperture by which it communicates 

 with the boiler is closed by a stem, at the lower part of which is a float, com- 

 posedof cork, or some light wood, and covered with copper. When the water get s 

 00 low, the float .and stem descend with it, and the aperture being thus un- 

 t opped, the steam nishes out through the whistle, and gives notice of the 

 e ficiency .—/Hoen/oc's Advocate. [Many years since a plan was adopted 

 i having a disc or plate of copper or other metal attached to some part of 



a boiler, which was made weaker than the boiler, so that if there should 

 be too great a pressure on the boiler, this disc would rend asunder and 

 permit the escape of the steam, and, in some cases, allow the water within 

 the boiler to flow on to tlic fire and extinguish it. With regard to the 

 second improvement— a steam whistle has been adopted some time past in 

 this country, and a plan very similar to the one described above, was 

 adoptedby Messrs. Maudslays and Field, for the engines, at the water works 

 at Brentford.— See Journal, vol. I., page 3/5. Ed. C. E. and A. Journal.] 



Elect ro-magtietie Engines.— A new galvanic battery, called the mechanico- 

 diemical battery, has lately been invented by Mr. A Smee. of the Bank of 

 England. »hicli promises to supersede the other forms now in use. Its prin- 

 ciple is simple, as its power depends entirely upon finely divided platinum, 

 dcp.isiled by means of a simple galvanic arrangement upon any other metal 

 which IS unacleil upon by dilute sulphuric acid, the only fluid used. At pre- 

 sent he finds that silver or plated copper answers admirably for the reception 

 of the platinum, but iron, when platinized, has the same power for a time as 

 these metals, though the iron becomes gradually dissolved. He also fiiids-^ 

 that with his battery porous tubes can, iu most cases, be dispensed with, and 

 that the battery can be advantageously made in any of the various forms 

 lutherto employed. Its effects are more powerful than those of the sulphate 

 of copper batteries, and in action it is less expensive. The practical appli- 

 cation of galvanic batteries, except as an instrument of research in the labo- 

 ratory of the student, is principally confined to the explosion of powder 

 underwater., or in other mining operations,, for which purposes it appears 

 useful, from its being small iu compass, and requiring scarce any manipu- 

 lation. Whether it may ever be used for locomotive purposes, still remains 

 doubtful, but who knows whether in future ages electro-magnetic engines 

 may not take the place of steam-engines. — Atlas. 



Oil a simple mode of obtaining, from a common Argand Lamp, a greatli/ in- 

 creased quayititij of Light, by Sir J. F.Herschel.—The following simple, easy, 

 and unexpensive mode of greatly increasing the quantity of light yielded by 

 a common Argand burner, has been used by me lor some years, and'is adapted 

 to the lamp by which I n rite, to my greatlv-increased comfort. It consists 

 in merely elcvatin" the glass chimney so much above the usual level at which 

 it stands iu the burners in ordinary use, that its lower edge shall clear 

 the «/>;;< r edge of ihe circular wick by a space equal to about the fourth 

 part of the exterior diameter of the wick itself. This m.ay be done to any 

 lamp of the kind, at a cost of about sixpence, by merely ndapting to the 

 frame which supports the chimney four pretty stifl steel wires, but in such a 

 manner as to form four long up'right hooks, in which the lower end of the 

 chimney rests; or, still better, if the lamp be so originally constructed as to 

 •sustain the chimney at the required elevation w ithout much addition, by thin 

 laminee of brass oi iron, haiing their planes directed to the axi.s of the wick. 

 The proper elevation is best determined by trial ; and as the limits within 

 which it is confined are very narrow, it would be best secured by a screw- 

 motion applied to the socket on which the laminse above mentioned are fixed, 

 by which they and the cliimney may be elevated or depressed at pleasure, 

 without at the same lime raising or lowering the wick. Approximately 

 it may be done in an instant, and the experiment is not a little striking 

 and instructive. Take a common Argand lamp, and alternately rai.^e 

 and depress the chimney vertically from the level where it usually rests, 

 to about as^'ar above the wick, with a moderately quick but steady motion. 

 It wdl be immediately perceived that a vast dillerencc in the amount of li.p,ht 

 subsists in the difl'erer.t posit ons of the chimney, but that a very marked 

 and sudden maximum occurs at or near the elevation designated in the com- 

 mencement ; so marked, indeed, as almost to have the eflieet of a flash if the 

 motion be quick, or a sudden blaze as if the wick-screw had been raised a 

 turn. The flame contracts somewliat in diameter, lengthens, ceases to give 

 ott Smoke, and attains a dazzling intensity. With this great increase of 

 light, there is certainly not a corresponding increased consumption of oil : at 

 least the servant who trims my lamp reports that a lamp so fitted consumes 

 very little, if any, more oil than one exactly similar on the common plan. — 

 Phil. Mag- 

 Steam Boilers.— At the last sitting of the Society for the Encouragement of 

 National Industry, and on the report of M. Se^guier the younger, a gold 

 medal was decreed to Ihe elder M. Chaussenot, for an apparatus to render 

 the explosion of steam-boilers impossible. According to ihe report, his in- 

 vention is perfect, both as regards its improvemenis or the safety-valve, and 

 an ingenious contrivance to give notice to the crew and passengers of im- 

 pending danger. Even the contingency of wilful mischief is provided against ; 

 as in the event of all the warnings of bis machinery failing, or being disre- 

 garded, the steam flows back upon the furnace, extinguishes the fire, and 

 destroys all possibility of an explosion. 



Turning Lathes.— At an ordinary meeting of the .Society of Arts, the 

 large silver medal was awarded to Mr. J. Hick, jun., of Bolton, for 

 an improved expanding mandrel for turning-lathes, ft is necessary that 

 a mandrel should fit so accurately, as to bite un the inner surface with a 

 force iuffijient to counteract that of the tool, and, in the ordinary mode, the 

 same ma idrel cannot be used for tw o pietes w hich are of difi'erent diameters. 

 Consequentlv, in many engineering establishments, a stock of mandrels is 

 kept, amounting to 650 or 700. Mr. Hick piu-poscs to do the same work 

 with eight sizes of the mandril, from one inch and a quarter to ten inches. 

 He efl'ects bis object by having the spindle of the mandril shaped on the 

 frustrura of a cone, on the face of which are four dove-tail grooves to receive 

 wedges, the under faces of which have the reverse inclination ot the cone, so 

 that the lines of their outside laces are always parallel with the a.xis of the 

 mandrel. A nut is screwed on the spindle, which acts on the w edges througli 

 Ihe medium of a conical cup, which drives them up to their bearings inside 

 of the work. 



The Retarder.—VuW trial has now been made of this valuable invention of 

 R. W. Jcarrad, Jun„ Esq., for retarding (not locking) Ihe w heels of carriage 

 when going down hill. Mr. Dangcrfield. coach proprietor, having had it 



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