i84a.j 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



SOT 



way in the valve-seat. This valve is weighted by a helical spring, 

 of sufficient power, according to the required pressure of the 

 steam ; and when it is intended to be used as a reserve safety- 

 valve, the spring is to be placed around that part of the stem 

 below the valve — tliat is to say, within the boiler. The advantage 

 of this form of construction of valve over the ordinary valve is as 

 follows : — As soon as the pressure of the steam raises the valve 

 from its seat, the flange, being exposed to the pressure of the 

 steam, presents an increased surface, which compensates for the 

 increasing resistance of tlie helical sping, until the valve has been 

 raised to a height equal to tlie area of the steam-way, when it 

 allows the steam, or vapour, to escape freely. When not intended 

 as a reserve safety-valve, this valve may have the spring placed 

 above it. Another valve, which is called an indicator safety-valve, 

 is exhibited, consisting of a piston, which is fitted into a tube, 

 having a spring attached to it — lateral openings being made in the 

 tube, to allow the steam to escape when the piston becomes raised 

 above such openings ; and by making the said tube moveable within 

 another one, the " blowing-off" point may be varied at pleasure. 

 An index, like that of a barometer, may then be attached to the 

 stem, or rod, of the piston, and will indicate very slight variations 

 of pressure. A regulating-valve is attached, the construction and 

 arrangement of which is as follows : — There is a short socket-pipe, 

 having two conical valve-seats formed therein, into which the valves 

 fit — such valves being connected together, or formed upon one 

 stem, into which one end of a rod is screwed, or otherwise made 

 fast, and the opposite end of the said rod attaclied to an eccentric 

 spindle, working through a stuffing-box, to which a hand-lever is 

 fixed — such lever and rod being for the purpose of opening, or 

 closing, the regulator-valve at pleasure. 



The anti-primer before-mentioned is formed in the following 

 manner : — Two distinct and separate plates of sheet metal, the 

 outer edges of which ar« securely fixed to the inside of the boiler, 

 by rivetting, or otherwise, the said plates being inclined towards 

 the centre of the boiler, care being taken to leave a space between 

 the inner edges of the two plates, so as to reserve a channel 

 lengthwise of the boUer, for the passage of steam into the steam- 

 chamber thus formed, and within, or in connection with which the 

 regulating-valve, is situate the steam-pipes which lead to tlie cjlin- 

 ders being connected thereto. Instead of forming the anti-primer 

 of two separate strips, or pieces, of metal, the same result may 

 be obtained by forming it of one strip, or piece, of metal, of the 

 shape shown — the said plate being pierced witli an infinite number 

 of small holes. The construction and arrangement of the feeding- 

 apparatus are as follows :— There is a metal cylinder, which should 

 be bored perfectly true and cylindrical, fitted with a piston, the 

 rod of such piston forming the' plunger, or ram, of the cold water 

 pump, the barrel of which serves as a compound gland for the 

 stuffing-box of the cylinder and pump-barrel. The slide-valve, 

 which may be made to cover or uncover the ports, or passages, in 

 the cylinder, by the opposite sides of the piston coming into con- 

 tact with the levers, which are connected to the slide-valve by a 

 rod or rods. There are spherical-valves (the seats of which are 

 knife-edged), formed within the spherical flange pieces, which 

 have openings for establishing a communication between the ten- 

 der, the pump-barrel, and the steam-boiler, as exhibited. The 

 modus operandi of this feeding-apparatus is as follows : — Upon 

 steam being admitted from tlie boiler into the cylinder, through 

 the steam-port, or passage, tlie piston wOl be acted upon, and the 

 ram, or plunger, be withdrawn, the water from the tenders wiU 

 raise the valve, and enter the barrel, to supply the space previously 

 occupied by the plunger, or ram ; by this time the piston will have 



acted upon the lever, so as to cause the slide-valve to uncover the 

 port, or passage, and cover the port, or passage, P,, thereby al- 

 lowing the steam on the other side of the piston to escape through 

 the exhaust-pipe ; the piston will now be impelled in a contrary 

 direction, and the plunger, or ram, entering the barrel, will cause 

 the one valve to be closed, and the other to be opened by pressure 

 of the water therein, which as the plunger, or ram, advances, will 

 be forced into the boiler, to supply the deficiency of that water 

 which has been converted into steam ; R,, R,, mark wheel-guards, 

 or safety-breaks, which are each composed of a strong band, or 

 strap, of iron, placed like a splasher over tlie wheel to be pro- 

 tected ; the inner surface of the said guard, or break, is formed of 

 the converse shape to that of the tyre, and fixed securely to the 

 framing, or boUer, or both, as near to tlie top of the wheel as the 

 play of the bearing -springs will admit of, and as near to the back 

 of each wheel as possible, without touching it. 



To each side of the engine a bar of iron is placed, and securely 

 fixed in a longitudinal direction — such arrangement being intended 

 to ))reserve such wheels in a vertical position, and thereby support 

 the engine, in the event of the axles breaking, and to operate at 

 the same time as a break, to retard the motion of the engine, in 

 the event of any such accident. Another improvement in locomo- 

 tive engines consists in arranging that part of the boiler known as 

 the fire-box, in such manner that the height of the water in this 

 part of the boiler shall at all times be at a proper level, wliich is 

 effected by what is called an anti-fluctuator, which is a separate 

 partition-plate across the water space, or an extension of the plate 

 to which the tubes are fixed as shown ; and, by causing the water 

 to be fed to the boUer at that part which surrounds the fire, it will 

 appear evident that the barrel of the boiler can only receive its 

 supply of water from that which overflows the said partition-plate. 

 Having described the nature of his invention, the patentee re- 

 marks, that he does not claim the exclusive use of any of the 

 separate parts above-mentioned and referred to, when considered 

 per se and apart from the purposes of the said invention, as 

 hereinbefore set forth and described. 



Improvements in Perforating Glass for VENTriATioN. 

 Patented by Mr. J. Lockhead, of Milton, Gravesend.. — In forming 

 plates, sheets, lenses, or other forms of glass, the glass, when in a 

 semi-fluid state, is poured from the pot on to the casting-table — 

 the stream being followed by a pressure-roller, for the purpose of 

 flattening it ; and, while the glass is in a plastic state, a metal 

 mould, with teeth or projections on its under-side, according to 

 the pattern required, is applied to the surface, forcibly pressed 

 down, and left in that position until the glass has set ; after which 

 it is to be removed, and the glass will be found to be perforated, 

 in corresponding shapes to the jirojections on the mould. To efl'ect 

 this in the most complete manner, a screw-press, made to the size 

 of the casting-table, is used, very similar to a common copying- 

 press, and difl'erent pattern-moulds being fixed to the lower end of 

 tlie screw, and worked by a cross handle. 



Improvements in obtaining Oxide op Zinc prom the Ore. 

 Patented by M. C. A. F. Rochaz, of Paris. — By this process, the 

 employment of retorts, as by the old method, is dispensed with, 

 the fuel and labour economised, the operation completely inde- 

 pendent of the skill of the workman, and the loss of metal, inci- 

 dental to the old method, prevented. Ores of lead and zinc may 



40 • 



