[ l-S^ ] [Jimc 1, 



NEW PATENTS AND MECHANICAL INVENTIONS. 



To Edgar Dobbs, of SoutlmnrU ; for 

 a VarieUj of Compositions for nmkiiip 

 a Water-proof Cement, Mortar, tiuil 

 Stucco ; the same being also applicable 

 a» durable Colouring - washes for 

 Buildings. 



THIS invention consists, first, in 

 making, by moans of water, a 

 proper admixture of lime, or its cariio- 

 nates, with any one or more of tlic 

 following substances, viz. (;lay, loam, 

 mnd, sirale, road dirt or dust, soil, ochre, 

 cheap metallic oxyds, t)rcs, pyrites, 

 blcnile, sand, stones, earths, ashes, and 

 all such earthy bodies (lime and its car- 

 bonates as before excepted,) as can he 

 reduced to powder, and will not vitrify 

 by the heat which they arc subsequently 

 to undergo. Secondly, in expelling tiie 

 redundant water. Thirdly, in burning 

 the mixture wiien in a concrete slate. 

 And, lastly, in reducing that mixture to 

 powder: this powder is the composition 

 for making the ccmout, mortar, stucco, 

 add was!). 



By carbonates of lime, he means 

 chiijk, common limestone, marbles, 

 oyster and other marine shells, earths, 

 and earthy bodies, that will slack or fall 

 into powder, either by contact of air or 

 water, after being burnt. By ashes, he 

 irieans the niiconsnmed residue of coal 

 or vegetable bodies after burning. The 

 process is this: — First he reduces the 

 Jime, or its carbonate, to a fine state of 

 division, the lime by slacking, and the 

 ratbonatcs by grinding them, with or 

 without water, by the common melJiods 

 used for grinding whiting, white lend, 

 or flint, or by some other metliod equally 

 cflectual, until they are in such a state 

 of disintegration, as, by subsequent agi- 

 tation in water, will allow the finer par- 

 ticles to remain in suspension a siiflicient 

 time to pour off the water from the 

 grosser particles (which will have sub- 

 sided, and may again be ground), and 

 that the particles so poured off be about 

 as fine as those of common whiting. 

 Secondly, he reduces the other sub- 

 stance or stibstanccs, with which he 

 wants to mix the lime or its carbonates, 

 to particles about the same fineness as 

 those before described ; th( hard ones, 

 or those which require grinding, are 

 reduced either with or witliout water, 

 and the finer parts, when mixed with 

 water, poured otf as before ; or, if the 

 selected substance or substances be 

 sufficiently soft of themselves, omit the 



grinding, and simply diffuse tliem in 

 water, by mixing and agitating tlieni in 

 it till the rn;itt(r Iieeomc-; of about a 

 creamy consistency, an<l tlieii wash otf 

 as bef(no. Thirdly, he lakes certain 

 portions of the washed lime, or its car- 

 bonate, according to the nature of the 

 required composition, and of the other 

 washed substance or substances, and 

 mixes and incorporates them well toge- 

 ther iit a vessel, or other receptacle, fit 

 for the purpose ; or the incorporation may 

 be made by adding to the bodies, iir 

 their natural state, a small quantity of 

 water, and then grinding and tempering 

 them till they become homogeneous and 

 plastic. 



The diffused ingredients are tlion t« 

 rest, when the clear water is to bo 

 drawn off, find the remainder of it eva- 

 poiatcd (as is also to be the case if they 

 liave been tempered), either by artificial 

 lieat, or by exposure to the atmosphere, 

 till the mass becomes sutTiciently stilf 

 to be cut or moulded into pieces for 

 burning. 



The burning mny be performed in n 

 common lim?.ktln, stove, or furnace, or 

 even without any apparatus of that na- 

 ture, observing tliat the intensity and 

 duration of heal he suflicient to consnnu; 

 the combustible part of the ashes or fuel 

 when contained in the mixture, ami 

 expel carbonic acid from carbonate of 

 Jime. without vitrifying any of the sub- 

 stances. The burnt pieces aie after- 

 wards to be reduced to powder, by 

 grinding between horizontal stones, or 

 t>y any other means usually cmpldycd 

 for grinding dry substances ; and then 

 the composition is in a state fit for use. 



If the Composition he intended for 

 cement that will set in about ten or 

 twenty minutes, and to be adapted to 

 the general jvirjjoses of building, the 

 proportif)ns shoukl be (each of the 

 ingreilients supposed to be in a dry 

 stnto,) about three parts by weiglit of 

 chalk, or, in lieu of clialk, one and a 

 half of lime, one part of sneii clay as is 

 found in marshes on the baid<s of the 

 Thames, or such as turn red by burning, 

 and one part ash, snc'i as is sold in 

 London by the dealers in breeze. If it 

 be required to sot sooner, a greater pro- 

 portion of lime or the carbonale must 

 be taken ; and, if not so soon, a greater 

 proportion of jhe other ingredients. 



If the composition be intended for a 



wash to resemble stone, it will be pro- 



5 per 



