313 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[October. 



combininET tlif nintprinls on the plain nn'! siin|i1e prnctic il principle of 

 a mere induration of water by livdrale of limp, receiving strength me- 

 clianically, not cliemically, hv the enclosure of real dovetails of coarse 

 sand, aided and assisted by the hydraulic pressure of the patentee, an 

 infinitely superior cement block would be formed. Imli-ed, no man 

 of prartieal science would for one minute entertain the bare idea of 

 adding to mortar (and it is infiiiitely worse to add it to the block) 

 either silicate of potas or anv other 8o/H^/e so/^ ; the grand object in 

 making cements being to avoid them, and prevent, if possible, their 

 future formation. It is, in fact, an inattention to th's desideratum 

 which lias begotten all the efflorescing, scaling off", discolouring 

 and salt forming characteristics of our artificial stone and stuccoing 

 compounds, not one of which that I have examined bespeak any in- 

 telligent practical knowleilge of true principle. Similar errors de- 

 stroyed all the real worth of Keane's labours, for s\ipposing that in 

 soaking plaster of Paris fsulpbat" of lime) of the first burning in a 

 solution of atiim (sulpate of alumina) and calcining it again, he drove 

 off the sulphuric acid and left aluminous earth commixed with his 

 plaster. He also became grossly deceived — he lost pelf, and the 

 public lost a'l the benefits which might have accrued from a really 

 lieaiitiful and invaluable compound, vvliereas th" subjpct of his patent 

 proved to he an intensely acid, efflnrescing, irjurious and readily de- 

 composing and decomposable one,- anri certainly one uhich nn rational 

 being would rely on for the decor. \tivp purposes of painting, for it 

 must be obvious to the veriest tyro, that in lieu of driving off sul- 

 phuric acid and leaving ahiminn liphind, his second calcination could 

 only drive off excess of water (with some li/He nc;V/), and le^.ve a con- 

 centrated super-siilphnte of the earth, in a word a stronger alum, the 

 very existence of which nould ni t only jpopardize a painting, but ab- 

 solutely destroy in time an ordinary joint between two marble blocks 

 — however beauliful in appearance at the onset ; for he could scarcely 

 be a sane man who anticipated carbonate of lime, in a crystalline state, 

 should withstand sulphuric acid in sulphate of alumina. But enongh, 

 let us return to lime in its real worth for practical use; and give such 

 directions as will ensure an infinitely bi'tter cement than any Roman 

 mason evrr used ; one which, without setting a single degree faster, 

 the grand ohjectinn to any general use of compo', even in a slight ad- 

 mirlurp in building, gives ir finitely greater iiidnrating power, am! 

 increasps in hardness by time, in lieu of carbonising and failing until 

 pulverisable by the fingers wherever its surfaces are exposed to air 

 and internally from its defective nature perishing per se. One which 

 not only has vo soluble salt in its present char.ictrr hut actually pre- 

 cludes the future formation of all soluble salts, and, in a word, becomes 

 as all mortar s' ou'd do, liarder than the siir'ouudii'g bricks, fortning 

 a real adhesion to them' and requiring the pickaxe to separate the 

 layers of work in lieu of the liurnau hand, which certainly suffices to 

 take down eighty out of every hundred modern buildings — certainly 

 the buildings of modern London. 



Here, perhaps, I may be allowed an episode, as of pri'ctical worth. 

 The suggestion was submitted to Mr. Barry,' but either from the 

 always injurious tendency of the system now universal of dividing 

 works into distinct contracts, leaving very little real control with the 

 architect, or from some other sinister causp, he has raised upon a 

 very beauliful and edicient fonn(l..tion, as regards the brickwork, a 

 common-place superstructure, the foundation itself being defective 

 only in one point — the non-adoption of the expedient^ actually forced 

 upon Mr. Stephenson for draining the wallings of certain railroads 

 were damp earth abuts upon Irickwoik, which would not only have 

 drained away circulating water hut have been a wise provision against 

 any accidental injury to the asphalt'c foundation from frost or other 

 casualty. I repeat that on this excpllett founilation he has raised a 

 common-place buihlino' with common-place luortar, in lieu of one 

 which might have been tlie lasting memento of an enlightened mind 

 and original genius," and rendered a real benefit to society. But to 

 return ; I would beg to impress on the minds of architects, civil and 

 military engineers, bniidirs,&c., that the more they reject the dogmas 

 of the closet, the more they repudiate the chemical nonsense about 



2 Mr. Latiito was esmpplled to use Fortp suds, solut'r ng of (arlionate of soda. &c., to 

 destroy the sulptiuric acid, and even then ttie surface of the painti-ii; reminded you of ihe 

 .mail poi. 



3 h.very otjservant i 

 adhesion at all ; nhen 



irlar of whiell we pn 



hat in ttie ordinary brickwutk of our day there ifl no 

 ieri-e consirleMhle adhfsi.>n in old Koman werk (the 

 ire been kept llifee yeari), 1 should shrewdly s'iBpect 

 briiks, an exj>eriienl ours never rei-ur 1 1 except by ne. 



* Thai is. the 

 missiyii at the F 



« it was suggested by ine also, thiougli 

 above Ihe surface of the asphlltic found 



f Imi^'tes, as auggested by me to the Royal Com- 



ctlaniiel, t( 



stogu.nl, 

 ewithbi.rjt 



nape gutters 

 casualty, and 

 1 that neither 



then 



from above nor below coidd any 



• 1 have specimens of the effect ofiliis barytic niotar putinio a wall in Mav, Juni 

 July, lti44, which have been much approved by ptaclical builders. 



silica as an aeiil and its action on lime, and look upon cement as an 

 imluratiiin or solidification of w.iter mecliauically strengthened by 

 (hivetails of the co.irsest s.ind, (a fact observed even in Pliny's day, 

 for he directs you to mix pieces of broken flint of a certain size not 

 exceeding " librnm unum") the more perfect will be the result; hut 

 to pr.ictice— let us give a tabular formulary which cannot be mistaken 

 ami then explain its theory to bear us out. 



Dnrki 



, Bath or Durdhan Down lime one load. 

 Sh.irp river sand two loads, 

 Native carbonate of bnrytes, finely ground, two hundred \ 



Mghls, 



The barytes being sifted into the mortar after it is mixeil, that is, in 

 working il up; and in using blue lias or any other lime for hydraulic 

 work or military works where additional power is required, the prac- 

 tice sliouhl vary thus much — one half of the native carbonate shouhl 

 be mixed with the lime and sand first and slaked (boiled) with it. 

 The theory of which is singular indeed, and became known to me 

 more than thirty years ago, that is to say, this refractory carbon ite, 

 which adheres so intensely to its carbonic acid gas as to ilefy the lime 

 kiln and ordinary furnaces — so perfectly so that all experimentalists 

 have been driven to the calcination of the artificial nilrale when 

 caustic barytes might he wanted — yields, at once, by the slaking pro- 

 cess, to lime in the active state, its gas and becomes caustic, and gives 

 an almost incomparable power in solidifving water without swelling 

 injuriously, and further, by the intense affinity of the barytic earth, 

 whtilly and solely destroys sulphuric acid or soluble sulphuric sails, at 

 present the real curse of all grout work — no lurlher proof of which 

 need be advanced than one moment's reflection with any practical 

 man, for every pr.iriicai man knows ifiat in one montll he can observe 

 the formation of sulphates of lime, alumina, magnesia, &c., all arising 

 from the oxygenisement of sulpUur in the slaking process,' and sub- 

 sequent action of sulphuric acid on the various bases existing in strontr 

 limes. And, as sulphate of barytes is strictly insohilile an,l non-tle» 

 coinposable in itself, anl really adds to the tlensity of a cement me- 

 chiinicalhj where it is specially required not to swell, and chemically 

 alsii, though in a lesser degree than carbonate, solidifies water like all 

 batyiic salts, it beci m»s as elegant an agent scientifically as it is a 

 practically nsefnl one. 



The expense of I his addition even at the present moment wonltl be 

 for buildings of magnitude trifling, and it is so abundant in Derbyshire, 

 Auglesea, &i-., as well as in North America, and very far from scarce 

 in Ireland, tint the moment ilemand enters the field the ctst will be 

 quite beneath either public or private notice. 



I have a sppcimen in a w.ill, now before me, of the mortar willi 

 which the fresco fr.ime mentioned in my last paper was filled which 

 h is been ex.imined an I tried by many practical builders, none of whom 

 believe, until Ihe explanation is given, the sheer simplicity of its 

 character; all declare it to be very fine compo indeed, and so un- 

 usually hard that a powerful blow with a strong spade scarcely makes 

 an impression upon it, while, as I before said, the setting power was 

 not visibly increased. I have now only to add, blocks ol this mottar 

 moulded and compressed, as practised by Ransom, exceed in density 

 and practical worth all the mixtures, and their name is legion, I have 

 either made or examined ; and it was an inspection of three wedges 

 shown liy me to my Lite friend Sir Anthony, then Mr. Cailisle, and by 

 him shown to Nicholsim, by Nicholson to the lale S.imuel Parkes, 

 which gave rise to Parkes' suggestion in one of iiis ess.iys, then io 

 M.S. preparing for the press, lor the use of b.irytesin mortar, and after 

 many fruitless attempts to calcine and render caustic the native car- 

 bonate (for noexpl.inatiun hid been conveyed to him) — the ess ly went 

 to press Willi engravings for calcining this carbonate? No; for cal- 

 cining a different silt — the sulph.ile, cjinmonly called cawk, and which 

 is re. illy an iueUicient and improper addendum ; for blue li.is or even 

 Dorking and other flare limes are sulphurous enough, albeit Phillips 

 and other analysts attribute to bitumen what belongs to sulphur. 

 Parkes w.is ignorant of the really beautiful natural action of caustic 

 lime on this refractory carbonate, which sooner vitrifies by fire llian 

 part with its carbonic acid gas. 



Tweuly-five years ago 1 built with it, and can most confidently call 

 on architects, bull. leis and men ol furtuine to try its powers; thev 

 will never regret it, on the contrary, In benefilting themselves and 

 their posterity, will m.itenally benefit the state; for, om-e fairly tried, 

 the demand will be immense; and its extent of worth is not easily^ 

 appreciatt d, for, independent of its Indurating power, its texture in 

 obviaiiug ihe ciicul.ition of damp by capillary .iltracliun, and its tutal 

 prevention of saline form ition (if oidinarv i.ire be used as towashmj; 

 sea s.ind, which is always charged vvitli muri.ite of soda and magnesia) 

 stamp It as a real desiJeraium. While lis powers are not limileil to 

 the mere uses of ordiu.iry works, it ought to enter the finest plasters 



' As fully explained in my last. 



