181.8.J 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



381 



NOTES OF THE MONTH. 



Branch Passenger Locomotives. — Several trips were made on Wednesday, 

 15th ult., on the West London Railway, with a little passenger-carriage 

 engine, the Fairfield, which has been constructed for one of the branches of 

 the Bristol and Exeter line. The engine, " tender," and carriage, which 

 have been constructed by Mr. Adams, of Fairfield Works, Bow, are con- 

 nected together upon one frame, and weigh, with coke and water, about 10 

 tons. The object sought is to economise the working expenses of branch 

 lines, and to introduce light rails and light engines into various districts of 

 the country, the p.issenger and goods traffic of which are not calculated to 

 pay a dividend upon the ordinary outlay for laying down the present cha- 

 racter of permanent way, and supplying the present locomotive and carriage 

 stock. The engine and carriage run upon six wheels. The engine has but 

 two wheels — viz. : the driving-wheels, which are in front. She is fastened 

 to the carriage by longitudinal side-plates, which are screwed together, and 

 also by bolts and screws through a transverse frame, so that when in work- 

 ing order the whole may be said to run upon one frame. The ongine has 

 an upright boiler similar to the little 22 cwt. express engine belonging to 

 Mr. Samuel, the resident engineer of the Eastern Counties Railway. The 

 boiler has 150 tubes of 1 J inch diameter outside, and 4 feet long. The fire- 

 box is 2 feet 6 inches, by 2 feet. The diameter of the driving wheels, which 

 have about 3 tons upon them, is 4 feet 6 inches; the cylinder 8 inches, and 

 the stroke 12 inches. The engine is to be worked at about 100 lbs. pres- 

 sure, and the consumption of coke is calculated at 10 lbs. per mile. In front 

 of the driving wheels is the tank, which holds 220 gallons of water. The 

 coke is carried in an iron box attached to the carriage. The carriage is a 

 composite one, and will afford sitting-room for 16 first-class and 32 second- 

 class passengers ; but by a slight alteration the same compartments might be 

 made to accommodate 60 persons. The cylinders of the engine communi- 

 cate with the axle through an intermediate crank shaft. This is connected 

 with the axle by side-rods. The trailing and centre-wheels run loose on 

 their axles; the axles also run loose in their journals. The trips were run 

 under great disadvantages. Being a new engine, her boiler is necessarily 

 dirty, and she runs stiff. It was not till three or four journeys had been 

 made that the priming could be kept down sufficiently to get anything like 

 an effective working pressure in the cylinders. But, with these disadvan- 

 tages, the little engine and carriage maintained a speed of 24 miles an hour 

 up 1 in 100, and 41 miles per hour down the same incline. About 30 per- 

 sons were in the carriage and upon the engine during these trips. Another 

 of these carriage engines is in the course of construction for the Eastern 

 Counties lines. The boiler is to be the common horizontal one. In a few 

 days the Fairfield will, no doubt, be in pretty good working order. We shall 

 then make a few more trips upon her, and be able to oflTer an opinion upon 

 her speed and power. — Herald, 



London and North-Western Sailway — Deterioration of Permanent Way. 

 — It is staled a committee has been appointed by the directors of the Lon- 

 don and North-AVestern Railway Company, consisting of Mr. Dockray, 

 the resident engineer; Mr. IM'Connell, the locomotive superintendent; 

 Mr. Madigan, the ballast-carrying contractor for the southern division of 

 the line ; and Mr. Crampton, C.E. ; for the purpose of discussing by what 

 means the comparative deterioration of the permanent way, caused by heavy 

 engines of different classes, may be ascertained. 



Certain Prevention of Explosions in Steam Engines. — It is impossible 

 for the force of elastic steam to produce the breaking of engines and rending 

 of boilers that so frequently occur, they are the work of the explosive 

 principle, when disengaged from its combination with steam. Similar in 

 its effects to lightning, it is identical with electricity in its distinctive pro- 

 perties ; its velocities are in effect unlimited ; it is devoid of weight, and 

 not subject to the laws of gravitation, which are inherent in all matter that 

 has weight, and it is hence evident that it may be conveyed away by si- 

 milar conductors. It is absolutely certain that the explosive principle is 

 disengaged from steam as it is let into the cavity of the nozzle, or valve 

 chamber, on the opening of the steam valve ; the pressure that kept them 

 combined is then in great part taken off, until the cavity is filled with 

 steam. There is no proper escape of the explosive element frem the 

 nozzle, which is heated, and in effect insulated, and the accumulation is 

 highly dangerous ; but it may be safely carried off by proper conductors — 

 those most convenient are small copper tubes. One end of a tube of proper 

 length is to be terminated in the best manner for the diffusion of the electric 

 fluid — the other end to enter the cavity of the nozzle, and have over its 

 orifice a slight valve, kept by a spring a little open, to allow the explosive 

 element to pass oft" by the tubular conductor, the valve to close by the force 

 of steam, as the cavity becomes filled therewith. The conductors of a con- 

 densing engine should be carrit^d high enough above the water in which 

 they terminate to preserve the vacuum. The security from explosions and 

 breaking of engines must be complete, the cost and trouble only nominal. — 

 J. Wilder : N. V. Tribune. 



Testing of Metal at Woolwich Dockyard.— The trial of the large guns 

 supplied to the Board of Ordnance, which has been carried on during the 

 last 18 months, for the purpose of ascertaining the best description of gun, 

 and the best metal supplied by contractors, has just been concluded, and 

 Colonel Dundas, C.B., and Mr. Monk, deserve great credit for the excel- 

 lence of their models. The former 32-pounder gun, of 50 cwt., is now 

 reduced on Colonel Dundas's principle of construction to 25 cwt., effect- 



ing a saving of IJ ton on each gun of that calibre — the average price of 

 the metal being from lOl. to 12/. per ton. There is also a saving of 6 lb. 

 of powder on each charge, the former charges being 10 lb., and the new 

 pattern being found equally efficient with a charge of 41b. The guns 

 cast at the Low INIoor Foundry, in Yorkshire, have been found to stand 

 the heaviest charges when fired, and will consequently receive the largest 

 orders. The expense of the trials has been considerable ; but the saving 

 which will ultimately be effected, and the knowledge that no danger is 

 now to be apprehended from the bursting of guns when placed on board 

 of ships, or mounted for service in the garrisons, must give confidence in 

 working them. A trial has also been made of a wrought-irou 9-pounder 

 gun, submitted by Mr. Morgan, of Bristol, but it had been found inappli- 

 cable to the service, in consequence of the great recoil breaking the cap 

 squares, or coverings, of the trunnions. 



Marine Compass.— A new invention, by Captain Sir Samuel Brown, 

 K.H., patentee of the chain cables, has been exhibited in the Hortsmouth 

 Dockyard. It is a compass in a glass box, sustained by a small pillar 

 with telescope slides, by which it can be elevated or lowered to any desired 

 height. It is designed to obviate the local attraction of the ships. The 

 card is transparent, and the whole apparatus will supersede the use of the 

 binnacle. There is a mirror attached to it, on which the helmsman will be 

 able to see the refiection of the compass card. A lamp will be placed 

 over it at night. The whole is a most ingenious contrivance, and, if suc- 

 cessful, will effect a great desideratum for the nautical world. 



Supply of Water from the New Red Sandstone. — We learn, from the 

 Manchester Guardian, that the mayor of that town and several of the coun- 

 cil, on the invitation of the directors of the Manchester and Salford Water- 

 works Company, proceeded lately to the works of the company at 

 Gorton, to witness the success with which a shaft had been sunk 

 into the new red sandstone. After inspecting the reservoir, they visited 

 the chief object of attraction — the splendid new and powerful Cornish en- 

 gine, wliich has just been put down by the company, and which was set to 

 work to exhibit its great capabilities in pumping up a vast volume of the 

 water obtained by sinking in the red sandstone to a depth of 70 yards. 

 The water is stored by means of galleries from the main shaft, which serve 

 as internal and subterranean reservoirs. The volume of water thus raised 

 by this engine is estimated to be equal to about 2,000,000 of gallons per 

 day, a quantity considerably exceeding the cxpeclalious of the company 

 themselves. 



A Neiv Method of Extracting Pure Gold from Alloys and from Ores. — 

 The following method of obtaining pure metallic gold in the form of a 

 spongy mass, has been practised by me for several years, and no account 

 of the process has, to my knowledge, heretofore been published. It is very 

 useful to the chemist and to the manufacturer, and is more economical than 

 any other method that I am acquainted with. After separating the gold 

 from silver, by means of a mixture of nitric and hydrochloric acids, as is 

 usually done, the solution containing gold and copper is to be evaporated 

 to small bulk, and the excess of nitric acid is thus driven off. A little 

 oxalic acid is added, and then a solution of carbonate of potash, sufficient 

 to take up nearly all the gold in the state of aurite of potash is gradually 

 added. A large quantity of chrystallised oxalic acid is now added, so as 

 to be in great excess, and the whole is to be quickly boiled. All the gold 

 is immediately precipitated in the form of a beautiful yellow sponge, which 

 is absolutely pure metallic gold. All the copper is taken up by the excess 

 of oxalic acid, and may be washed out. Boil the sponge in pure water so 

 long as any trace of acidity remains, and the gold is then to be removed 

 from the capsule, and dried on filtering-paper. It may be formed into rolls, 

 bars, or thin sheets, by pressing it moderately in paper. I have made se- 

 veral useful applications of the gold sponge thus prepared, and had a tooth 

 plugged with it in October, 1846, to which purpose it is well adapted. By 

 moderate pressure the spongy gold becomes a solid mass, and burnishes 

 quite brilliantly. The jeweller or goldsmith will find spongy gold to be 

 quite convenient when he requires it for a solder, and it is a convenient 

 form of the metal for making an amalgam for fine gilding. I have used it 

 for some years in soldering platina, and prefer it to the tilings of gold or 

 foil for that purpose. This method of separating fine gold from coarse is 

 very simple, and cheaper than the usual processes. It is applicable in the 

 separation of gold from ores that may be treated by acids, and is vastly 

 preferable to the method commonly used by chemists and assayers. When 

 making oxide of gold for dentist's use, the chemist will find that oxalic 

 acid, added to this potassic solution, will at once recover all the gold that 

 is dissolved in an excess of the alkaline solution. Many other applica- 

 tions of this very simple method will occur to chemists and artisans. — C. 

 T. Jackson : Siltiman's Journal. 



Extraordinary Block of Granite.— K block of granite, containing upwards 

 of 12,000 cubic feet of stone, and exceeding in weight 830 tons was lately 

 dislodged at the granite quarries of Messrs. Freeman and Co., at Maen. 

 A hole 9 feet deep having been bored, H pound of powder, with which it 

 was charged, produced a slight crack ; into this was thrown another charge 

 of 35 lbs., which, on explosion, threw out this immense block several yards 

 from its bed. Considering the largeness of some of the stones produced at 

 these quarries, it is astonishing in how comparatively short a time they are 

 prepared for exportation. A few days since, another large rock was un- 

 seated, measuring when wrought 150 feet, and in weight 11 tons; the 

 preparing and working of which was performed by a couple of men in 

 a week. 



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