1849.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



179 



d, rf, is a metal piston made either solid or hollow according to the 

 size of the valve; for small taps they may be solid, but where 

 weight is objectionable, as in large valves for water or gas mains, 

 the patentee prefers to make them hollow, e, is a screw firmly 

 connected to the piston at /; and passing through the nut handle 

 g. Now if this valve be connected with a water cistern or main 

 by means of the flange at b, the water wiU flow into the casing of 

 the valve as far as tlie rolling packing;', j, as shown, but no further. 

 The handle being now turned and the piston raised, the packings 

 h,h, and ?, i, will roll along between the piston and casing beyond 

 the outlet c, thus allowing the water to flow freely tlirough. The 

 act of turning the handle in the contrary direction will cause the 

 packings to roll back to tlieir former situation, and thus eiJ'ectually 

 cut off' the passage of the water. The patentee does not confine 

 himself to one outlet, but places any number of openings in the 

 circumference of the casing, and thus obtains any number of jets 

 that may be required. He prefers an oblong figure for the outlets 

 at those parts of the casing where the elastic packing rolls over 

 them in order that it may not ])ress far into them in the act of 

 rolling. Where great pressure of fluids is to be sustained, he pre- 

 fers rolling packings to be made solid, as shown in section, fig. 2, 

 but in the cas6 of glass or earthenware valves, cocks, or pumps, 

 or where very light jiressures are used, he makes the rolling pack- 

 ings hollow, and wliolly or in part fills them with air or otlier fluid, 

 and thus renders them more soft and yielding than when made 

 solid, but in either case causes them to be made of permanently 

 elastic materials, as hereinbefore described. 



The improvements in cylinders or barrels of pneumatic and 

 hydraulic machines consist in rendering them elastic by forming 

 them of, or lining them with, vulcanised india-rubber. These 

 linings are made of any required thickness, taking care to have 

 tlie interior surface as smootli and e\en as possible, and are attached 

 to the barrels or cylinders of pumps or other macliines, whether 

 formed of wood, metal, pottery, glass, or other material, by any 

 suitable cement or other means. The patentee forms tliese barrels 

 entirely of vulcanised india-rubber. Tlie pistons to be used in 

 these barrels may be such as have been before described, but he 

 prefers them to be made of some smooth and inelastic material, 

 such as glass or metal (preferring tin), or hard wood, and of such 

 a form as that the rubbing surface should present a curved or 

 rounded figure to the barrel, the part impinging being only of such 

 a breadt^ as may be necessary to prevent the passage of fluids. 

 When the entire barrels are made of vulcanised india-rubber, be 

 proportions the thickness to the diameter, the pressure of the at- 

 mosphere, and the duty the machine has to perform. By means of 

 these elastic barrels and linings, the amount of friction is greatly 

 diminished and the wearing parts rendered much more enduring 

 than with ordinary barrels. 



APPLICATION OF COAL TAR. 



KoBERT Angus Smith, of Manchester, for "impro demerits in the 

 application and preparation of coat tar." — Granted October 19, 184.8; 

 Enrolled April 19, 1849. 



This invention relates to coating the interior of water-pipes 

 with coal tar. 



The coal tar is reduced by distillation, or otherwise, to a thick 

 pitch-like mass, which is kept melted at a temperature of ,'«)0' 

 Fahrenheit (or such temperature as will keep tlie matter in a fluid 

 state), in an open vessel. The interior of the water-pipes is first 

 cleaned, to remove any oxide; and then the clean surface is coated 

 with linseed oil, particularly when the pipes cannot be immediately 

 coated with the coal tar. ' The pipes are heated to about 300^ 

 Fahrenheit in a stove; then they are immersed in the melted coal 

 tar, in which they are allowed to remain for about an hour; and at 

 the expiration of that time the coal tar will generally be found to 

 have attached itself closely to the surfaces of the pipes, both in- 

 side and out: the chief object, however, is to obtain a good coat- 

 ing on the inside. The patentee states that, in removing the pipes 

 from the melted coal tar, he has found it desirable to pour a 

 quantity of linseed oil on the coated surfaces, which he finds to 

 have the efl'ect of removing any excess of the coal tar; and the 

 oil, running into the coal tar, keeps it fluid, and prevents it from 

 beconnng unsuitable for the operation of coating the pipes. In- 

 stead ot heating the pipes before immersion, a like effect may be 

 produced by immersing the pipes in the melted coal tar after the 

 interior surface has been cleaned, and allowing them to remain 

 therein for some time after they have become as hot as the coal 

 tar: this process will generally occupy about one hour and a half. 



MANUFACTURE OF STEEL. 



Alfred Vincent Newton, of Chancery-lane, Middlesex, me- 

 chanical draughtsman, for ^^certuin inipnnvmentt,- in t/ie nianujacture 

 of steel." (A communication.) — Granted November 2, 1848; En- 

 rolled May 2, 1849. 



This invention relates to the process of refining the metal, and 

 forcing currents of atmospheric and gaseous air during the pro- 

 cess, so as to convert it into steel; and also to preparing the metal 

 previous to submitting it to the process of conversion into steel. 



The apparatus consists of the converting furnace, to the tuyere 

 whereof a blast-pipe is attached, formed into three passages, pro- 

 vided with valves for regulating the air currents. Two of the 

 passages communicate with two irmi receptacles in front of the 

 converting furnace — the centre passage passing between tliem and 

 to the frinit of the receptacles. These receptacles are provided 

 with gratings and ash-pits beneath, and with covers for closing 

 them. 



The process of converting the metal into steel by this apparatus, 

 consists in allowing the air to pass into the two passages of the 

 blast-pipe communicating with the receptacles, such receptacles 

 being tilled with charcoal, which is then ignited, and the recep- 

 tacles closed by means of the covers; the air thus passed through 

 the receptacles is formed into carbonic oxide, and enters the 

 tuyere of the converting furnace, where it is mixed with such a 

 quantity of atmospheric air from the centre passage, as may l>e 

 judged desirable, though the patentee states, that a large quantity 

 should generally be avoided. By means of the valves, the quan- 

 tity of gaseous or atmospheric air can be regulated by the opera- 

 tor. To prepare the metal for the process of conversion, the 

 patentee states, that if it be pig-iron, it is to be melted sufficiently 

 in a cujiola furnace, to which is applied the apparatus above 

 described; hut if it be wrought-iron, a plumbago crucible is used, 

 in which the metal is to be placed, being properly stratified with 

 charcoal, or carbonaceous material. 



OXIDES OF IRON. 



William LoNOMAin, of Beaumont-square, Middlesex, gentle- 

 man, for ^'inipn)rement-i in. treating the oxides of iron, and in obtain- 

 ing products tlierefrom." — Granted October 26, 1848; Enrolled April 

 26, 1849. 



The improvement relates to treating the oxides of iron for ob- 

 taining a black or dark coloured pigment, or a volatile oleaginous 

 product, or an inflammable gas. The oxide of iron is finely pul- 

 verised and mixed vvith carbonaceous matters. The proportions 

 vary considerably: — the addition of 10 per cent, of carbonaceous 

 matter is generally sufficient; but the patentee prefers a little 

 excess of carbonaceous matter, and mixes the oxide of iron with 

 from 12 to 15 per cent, of carbonaceous matters, or such a quan- 

 tity that, when the process is complete, a slight excess of carbona- 

 ceous matter will remain in the retort unemployed. Any kind of 

 carbonaceous matters, which are not too volatile or expensive, and 

 which can be mixed intimately with the oxide of iron, may be 

 used; but when not in a fluid state, they must be pulverised. 

 Those preferred are resin and tar. When resin is used, it must 

 be pulverised, and the oxide of iron mixed therewith in a dry 

 state. When tar is employed, the oxide of iron is mixed there- 

 with in a moist state, for the purpose of facilitating the incorpora- 

 tion of the materials; and the mixture is dried at a temperature 

 sufficiently high to deprive it of nearly the whole of its moisture, 

 and reduce it to a state of powder. 



The mixture is to be put into retorts or close vessels; and the 

 patentee prefers to use cast-iron retorts, of the ordinary kind, five 

 feet in length, and one foot in diameter, with a cover, to be 

 fastened on the open end, and a ring at the opposite end, for the 

 purpose of lifting it. A retort of this size may be charged with 

 IgCwt. of the mixture; and then (the cover being secured) it is 

 lifted by a crane, and placed in a suitable furnace, in a vertical po- 

 sition, vvitli the cover end downwards, in order that the volatile 

 products evolved from the mixture may be consumed, and thus aid 

 in heating the retort. The heat is to be gradually raised until the 

 whole of the retort has arrived at a low red heat; at which tem- 

 perature it must be kept until about two hours after the evolution 

 of the combustible volatile products has ceased; and then, the 

 process being complete, the retort is removed from the furnace, 

 and allowed to become cold, or nearly so, before the charge is 

 withdrawn — as it would be injured by contact with the air whilst 

 hot. The material produced will be black, or dark coloured, and 

 will form a good pigment for many purposes. Some carbonaceous 

 matters, when used in the production of this material, will cause 



24* 



