56 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Febeuabv, 



soften and yield, as well as to snap ; in either and in any case, involving the 

 rnin of lliu ImiUlings, the destruction of the property conlHled to tliem, and 

 danger to the lives of firemen or others within reach of the ruin. 



So great is the danger apprehended front the treachery of cast-iron in 

 buildings on fire, that the men of the London fire-engine estahlishment, who 

 go unhesitatingly, in the execution of their duly, into burning buildings, are 

 prohibited from going into parts or places which depend upon supports of 

 cast-iron, whilst they are allowed to trust themselves to burning timber 

 almost at their own discretion — a quality for which they are not, indeed, so 

 remarkable as they are for headlong and gallant daring. 



Cast-iron is constantly recurred to, neverilieless, as a means of economis- 

 ing space in the formation, and largely also in the support of the floors of 

 buildings which it is desired to render proof against fire ; and it is certain 

 that the use of beams, girders, and story-posts of cast-iron tends to that 

 effect : that is to say, the liability of the building to take fire is lessened by 

 the use of iron in place of wood, hut for the purpose under consideration — 

 power of resisting the action of fire when it occurs to matters stored in a 

 building, and is fed by such matters independently of the substances em- 

 ployed in the structure of the building — iron requires to he itself protected 

 from the action of the fire." 



Mr. Hosking goes on to suggest the mode in which iron can he 

 safely used for floors and ceilings ; hut he adheres to the opinion 

 that if pillars must he used, they should he of brickwork. 



We ourselves have witnessed the danger of using cast-iron in 

 exposed situations in buildings. We recollect, within the last four 

 or five years, the fire at Fenton's wharf, London Bridge, where the 

 warehouses were supported upon cast-iron hressummers, and which, 

 through being heated by the fire, and the cold water of the engines 

 falling upon them, were cracked, and in consequence the super- 

 structure was obliged to he taken down. In other situations, we 

 have seen the fronts of houses erected on timber hressummers which 

 have withstood the ravages of the fire, an external coating of about 

 an inch in depth of the timber being only injured by the flames. 



The preservation of life from fire is an object in which Mr. 

 Hosking deservedly takes great interest, and he has brought to 

 bear the results of his remarks on buildings at Paris, which we wish 

 we could transfer at some length to our own pages. After recom- 

 mending that party-walls shall be reduced to one-brick thick, on 

 condition of cross-walls or partitions being built throughout the 

 house of one-brick thick, and after stating the danger of the hollow 

 quartering partition generally used, he describes the system he 

 observed in Paris. 



" The plan referred to is, to frame and brace with timber quarterings much 

 in the manner practised in England, except that the timber used in Paris is 

 commonly oak, and is very generally seasoned before it is applied in building 

 in the manner referred to; and that, as before remarked, the carpenter's 

 work, or carpentering, of the French is not so good as that of the English. 

 The framed structure being complete, strong oak batten-laths, from two to 

 three inches wide, are n;iiled up to the quarterings horizontally, at four, six, 

 or even eight inches apart, according to the character of the work, through- 

 out the whole height of the enclosure or partition ; and the spaces between 

 the quarterings. and behind the laths, are loosely built up with rough stone 

 rubble, which the laths, recurring often enough for that purpose, hold up, or 

 prevent from falling out until the next process has been effected. This is, 

 to apply a strong mortar, which in Paris is mainly composed of what we 

 know under the name of plaster of paris, but of excellent quality, laid on 

 from or upon both sides at the same time, and pressed through from the 

 opposite sides so that the mortar meets and incorporates, imbedding the 

 stone rubble by filling up every interstice, and with so much body on the 

 suriaces as to cover up and imbed also the timber and the laths ; — in such 

 manner, indeed, as to render the concretion of stone and plaster, when 

 thoroughly set, an independent body, and giving strength to, rather than re- 

 ceiving support from, the timber." 



The same plan is applied in Paris to the stairs, and Mr. Hosking 

 recommends it for adoption here. He likewise gives a detailed 

 account of the French mode of making ceilings and floors. 



" But the French render theirfloors also so nearly fire-proof as to leave but 

 little to desire in that respect, and in a manner attainable with single joists, 

 as well, at the least, as with joists framed into girders. According to their 

 practice, the ceiling must be formed before the upper surface or floor is laid, 

 inasmuch as the ceiling is formed from above, instead of from below. — The 

 carpenters' work being complete, strong batten-laths are nailed up to the 

 under sides of the joists, as laths are with us; but they are much thicker 

 and wider than our billis, and aie placed so far apart, tliat not more, per- 

 haps, tiiaii one-half of tlie space is occupied by the laths. The laths being 

 aftixed — and they must he soundly nailed, as they have a heavy weight to 

 carry — a platform, made of rough hoards, is strutted up from below parallel 

 to the plane formed by the laths, and at about an inch below them. Mortar 

 IS then laid in from above over the platform, and between and over the laths, 

 to a thickness of from two inches and a half to three inches, and is forced in 

 under the laths, and under the joists and girders. The mortar being gauged, 

 as our plasterers term it, or rather, in great part composed of plaster of paris, 

 it soon sets sufliciently to allow the platform — which, it will be readily un- 



derstood, has performed the same office to the mortar which centering per- 

 forms to the parts of an arch or vault — to be removed onwards to another 

 compartment, until the whole ceiling of any room or story of a buildine is 

 formed. The plaster ceiling thus formed, is, in fact, a strong slab or table, 

 in the body of wliicli the batten-laths which hold it up safely in the air are 

 incorporated, and in the back of which the joists, from which the mass is 

 suspended, are imbedded. By the process, the under surface of the plaster 

 table has taken from the rough boards of the platform the roughness re- 

 quisite to facilitate tlie adhesion of the finishing coat of plastering, which is 

 of course, laid on from below. 



Wheiher the eventual surface is to be a boarded floor or not, however, 

 the flooring joists are covered by a table of plaster above, as completely as 

 they are covered by a plaster ceiling below. — Rough battens, generally split 

 and in short lengths, looking like ends of oak pales, stout enough to bear, 

 when laid from joist to joist, the weight of a man without bending, are laid 

 with ends abutting upon every joist, and as close together as they will lie 

 without having been shot or planed on their edges, so as to joint them. 

 Upon a rough loose floor thus formed, mortar of nearly similar consistence 

 to that used for ceilings, but not necessarily of the same good quality, is 

 spread to a thickness of about three inches; and as it is made to fill in the 

 voids at the ends and sides of the floor-laths upon the joists the laths be- 

 come bedded upon the joists, whilst they are to some extent also incorpo- 

 rated with the plaster, and the result is a firm floor, upon which, in ordinary 

 buildings, and in the public and commoner apartments of almost all build- 

 ings, paving- tiles are laid, bedded and jointed in a tenacious cement to form 

 the working floor. 



It may be added in explanation of the statement, that in Paris the practice 

 of forming a table of plaster over the joists when tiles are to be used as the 

 flooring surface, is employed also when a boarded floor is to supervene, — 

 that as the surfaces of the true joists lie under the mortar or plaster table, 

 a base is formed for the boards of what English carpenters would call stout 

 fillets of wood about 2 J inches square, ranged as joists, and strutted apart to 

 keep them in their places, over the mortar table, to which they are some- 

 times scribed down, and that to these fillets, or false joists, the flooring 

 boards are secured by nails ; so that in truth the boarded floor is not at all 

 connected with the structure of the floor, but is formed upon its upper coat 

 of plaster. The wooden floor thus becomes a mere fitting in an apartment, 

 and not extending beyond the room nor over the passages and landings to 

 the stairs, the floor in any room might burn without communicating fire to 

 the stairs, which, in their turn, if they could burn, could hardly endanger 

 the immediate safety of any inmate of the building, because of the complete 

 separation which the tiled and plastered floor of the landings effects between 

 the wooden stairs and the several apartments." 



The author remarks that a similar floor is used at Nottingham, 

 where the houses are said never to he burnt, and are free from 

 damp and vermin. 



Mr. Hosking objects to timber being laid hedwise in walls, or 

 joists being let into them, but recommends that the rafters be let 

 in and properly secured against fire. 



We may observe, upon a note of Mr. Hosking's as to Flemish 

 bond, that he says he never saw Flemish bond in Flanders, at 

 Rotterdam and the Hague, Antwerp, Brussels, Liege, Cologne, 

 Mentz, and Frankfort. Now there is only one of these towns in 

 Flanders, and this is no proof that J'lemish bond is not to be found 

 at Ghent, Bruges, Courtrai, Ostend, Ypres, Dunkirk, Lille, or 

 other towns in Flanders. 



Of French carpentry, Mr. Hosking says that it is much behind 

 our's, so that in framing the floors no important bearing is, or in- 

 deed may be, trusted to the framed joint, dognailed stirrup-straps 

 of iron being always brought in aid. He says, however, that their 

 boarded floors are always tongued in the joints, and almost always 

 parquetted, and so resolved into compartments of various figures, 

 and being tongued and edge-nailed, no nail or bradheads appear 

 upon the surface to dot over and disfigure the floors, which being 

 for the most part of wainscot, are far more sightly than the best 

 executed deal battened floor with us. 



With regard to Parisian masonry our author states, 



" It is by means of the girder bearing upon the solids of the walls, though 

 with bad carpenters' work, or carpentering rather, that the French are aide 

 to carry up their soft stone rubble walls to heights that would frighten even 

 a London builder, and that would certainly be unsafe if the walls were 

 seamed with wooden plates, and shaken by floors of single joists. The 

 author, being at Paris in 1846, measured the thickness in the ground-floor 

 story of a newly-built coursed-rulihle party-wall, in the Rue de la Banque 

 (the Gresbam Street of Paris), and found it to be exactly 18 English inches 

 in that part, whilst the total height of the wall was not less than 8o feet. 

 The wall ran up of that same thickness through six stories, a height of not 

 less than 65 feet, and was terminated by a gable of from 12 to 15 feet high, 

 of the same kind of structure ; and there was besides a vaulted basement 

 story, throughout which the wall might have been 20 inches thick, as other 

 similar walls then in progress to neighbouring buildings proved to be. And 

 it is by means of the solidity given to the floors by the girders, and the solid 

 bearings which the girders obtain, that the floors are able to carry the dead 



