isig."] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



301 



WHITE-LEAD PAINT. 



Hugh Lee Pattinson, of Washington-house, Gateshead, clie- 

 mical manufacturer, for '■'■ improvements hi miuiiifricturhiy a certain 

 compound or certain compounds of lead, and the application of a cer- 

 tain compound or certain compounds of lead to various useful purposes." 

 — Granted February U, 1849; Enrolled August 1+," 1849. [Re- 

 ported in Newton's London Journal.'] 



The patentee commences his specification by stating that he has 

 discovered that when half an equivalent or thereabouts of lime, 

 soda, potash, ammonia, or barytes, is added to one equivalent of 

 chloride of lead, both in solution, the whole of the lead is precipi- 

 tated as a definite compound of one atom of chloride of lead and 

 one atom of hydrated oxide of lead, which, when dried at 21*2° 

 Fahr., or under, hag the composition just stated or PbCl -j-PbO'HO, 

 but when dried at a temperature varying from 212^ to 350^ it loses 

 more or less of the atom of water and becomes or approaches to 

 PbCl + PbO. If less than half an equivalent of the alkaline pre- 

 cipitant is employed, the same definite oxichloride of lead is pre- 

 cipitated, but some of the chloride of lead remains in solution. 

 The oxichloride of lead, thus produced, possesses a brilliant white 

 colour and great "body" qualities, which render it an excellent 

 pigment and useful for most purposes to which white-lead is ap- 

 plicable. 



The invention consists in the manufacture and application of 

 this oxichloride of lead, or sucli other compounds of oxide of lead 

 and chloride of lead as shall result from the following mode of 

 manufacture: — The patentee states that lime will answer as well 

 for the purposes of this invention as any other of the alkaline pre- 

 cipitants above-named; and he prefers to use it on account of its 

 cheapness. He first makes a saturated lime water, by throwing 

 an excess of slacked lime into a tub, filling the tub with water, and 

 allowing it to stand until it becomes clear: the clear liquor will 

 contain in from 770 to 780 parts, 1 part of lime; and therefore 

 1 cubic foot of it will contain 567 or 568 grains of lime. A solu- 

 tion of chloride of lead is then made by dissolving it in boiling 

 water, in the proportion of 1 lb. of pure chloride of lead to 1 cubic 

 foot and a fifth of water: as some water contains earthy salts 

 (sulphates or carbonates, or both) which precipitate lead, the 

 patentee prefers to use such an excess of chloride of lead, as will 

 compensate for this loss. The solution is prepared by introducing 

 the chloride of lead and boiling water into a wooden barrel, pro- 

 vided with a revolving agitator; and then it is run into cisterns to 

 settle. The clear solution of the chloride of lead is mixed, while 

 Btill warm (because if allowed to become cool it would deposit 

 some of the chloride of lead), with an equal bulk of tlie lime water; 

 on this taking place, the insoluble oxichloride of lead is imme- 

 diately formed and speedily settles to the bottom of the cistern, 

 leaving a clear supernatant liquor (a weak solution of chloride of 

 calcium); and, after this liquor is drawn oif, the precipitate is col- 

 lected and dried. 



As the operation of mixing the lime water and the solution of 

 chloride of lead requires to be performed in an instantaneous 

 manner, the patentee prefers to employ for this purpose two 

 tumbling boxes, of about 16 cubic feet capacity, which are charged 

 with the two liquids and simultaneously upset into a cistern, in 

 which the oxichloride of lead is instantaneously formed, and from 

 which the mixture flows into other cisterns where the oxichloride 

 subsides. 



The patentee states that although he has only mentioned pure 

 crystallised chloride of lead in the description of the process, yet 

 it is not absolutely necessary that it should be in this form; for a 

 rough chloride, made from lead ore and its equivalent of muriatic 

 acid, boiled to dryness, will answer, provided it be well washed, to 

 free it from chlorides of iron, manganese, or other bodies likely to 

 injure the colour of the oxichloride. The exact proportion of 

 pure chloride contained in the rough chloride should be ascertained 

 previous to use, in order that the proper quantity may be mixed 

 with the lime-water. If, however, a solution of chloride of lead 

 of uncertain strength is obtained, or lime-water not quite satu- 

 rated, they can be used with but little disadvantage; for it is only 

 necessary to be careful not to add an excess of lime {i.e., not more 

 than half the equivalent), which can be easily ascertained after a 

 few trials, by filling the lime or lead tumbling-box more or less 

 with its respective solution, as the trials may direct. 



The patentee says that it wiU not be necessary to describe any 

 particular mode of proceeding with soda, potash, ammonia, or 

 barytes; for if ever it should happen that these bodies could be 

 used in preference to lime, it would be merely necessary to make 

 s solution of each of known strength, and to use it with chloride 

 of lead in the same manner as the lime-water. 



The patentee claims the manufacture of oxichloride of lead, 

 having the composition of one atom of chloride of lead and one 

 atom of oxide of lead, with or without an atom of water (or an 

 oxichloride of lead as near this comjtosition as the nature of the 

 manufacturing operations may admit), by the use of chloride of 

 lead and lime, soda, potash, ammonia, or barytes. And he claims 

 the application and use of this oxichloride of lead as a white paint, 

 as a base for coloured pigments, as an adhesive cement for joints, 

 and for many other purposes to which white-lead is commonly ap- 

 plied. 



WALLING. 



John Taylor, of 22, Parliament-street, Westminster, architect, 

 for "«« improved mode of constructing and fencing walls."* — Granted 

 February 8; Enrolled August 8, 1849. 



This invention relates to the construction of brick and other 

 walls witli a facing or ashlaring of stone, artificial stone, tiles, 

 bricks, cement, earthenware, glass, or other 



suitable material The facing is made into _ — i?— -^-ir 



blocks of such form that each block may [_ j;__JL 



be suspended on the brick or other main a f \ ^1 



work of the wall below, by a shoulder, and L™„^ — ,.^ ._ij 



weighted by the brick or other work above, 

 without bearing on the bed or under sur- 

 face of tlie facing-block, so that it cannot 

 be injured by the settling of the brick- 

 work, as sliown in the annexed figure, a, is 

 the brickwork, three or more courses of r 



wliich are first carried up, and the mortar- ai. ,_ 



bed laid; then the facing-block 6, is sus- T 



pended thereon by the shoulder c; and, j^ 



when the shoulder is weighted by the ' 



brickwork above, the bonding is complete. As a general rule, the 

 height of the facing-blocks is to be such as to leave their weight 



L. 



1 



JL 



suspended on the brickwork by the shoulder c, without the blocks 

 bearing on the bed or lower surface d, 



* By a disclaimer, dated April 9, lH49, the patentee has struck oul the words 'and 

 fencing' from tlie title uf his patent, uliicli uow leads thus: — ' for an improved mode of 

 coDStructiug walls.* 



PAPER-HANGINGS. 



John Ebwood, of Hoxton, Middlesex, paper-hanging manufac- 

 turer, {or '■'■ improvements in the manufacture (f paper-hangings." — 

 Granted February 15 ; Enrolled August 15, 1849. 



These improvements relate to that class of paper-hangings 

 known as coloured marble and granite papers, and such as are use<l 

 for covering walls in houses and other buildings. In using the 

 term " coloured marble papers," it is to be understood to mean all 

 coloured marble papers, with the exception of those manufactured 

 in imitation of white marbles. 



In manufacturing marble and granite papers, two modes of 

 operation are pursued in the application of the colour to paper to 

 give the desired effect ; one is by means of blocks having engraved 

 surfaces, by which the colour is printed or transferred on to the 

 paper ; the other mode is by applying the colours by hand, by 

 means of brushes and crayons, the veining and other effects required 

 being executed according to the taste and skill of the workman. 

 These modes of proceeding being well known, it is unnecessary to 

 describe them further, the present improvements having reference 

 to the hand-made marble and granite papers, or those in which the 

 colour is applied with brushes and crayons by hand. To coloured 

 marble or granite paper-hangings it has been usual to apply a coat- 

 ing of varnish after they have been hung or pasted to walls, to give 

 them the glossy or polished appearance of the materials of which 

 they are an imitation, but the colours used in the manufacture pro- 

 duce only a dull representation of the efl^ect desired ; whereas, by 

 the patentee's improvements, the coloui's are so prepared and ap- 

 plied to the paper, as to be capable of receiving the desired polish 

 in the ordinai-y manner of glossing or polishing papers known as 

 " satin" papers ; by which the necessity of varnishing the paper 

 after it is hung is entirely obviated, the paper when so finished 

 presenting a glossed or polished appearance, presented by the sub- 

 sequent operation of varnishing. 



In conducting this new manufacture of coloured marble papers, 

 the patentee proceeds in a somewhat similar manner to the ordi- 

 nary mode of manufacturing hand-made papers. The papenis pre- 

 viously prepared with a coating of colour as a groundwork, the 



