158 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL 



[May, 



shall here lay before our readers some particulars of a dwelling house 

 lately constructed entirely of beton, by M. Jean Auguste Lebrun, 

 upon his estate at Marsac near Albi, in the department of Tarn. This 

 building consists of three stories, with three rooms in each floor, and 

 a large granary or garret at the top. Along the front of the house ex- 

 tends a gallery which has a height equal to that of the building itself. 

 Not only are the walls of this house composed of beton, but each 

 floor is supported upon arches of beton thrown across from one wall 

 to the other, so that throughout the whole building scarcely a particle 

 of timber is made use of. The arches which support the first or 

 principal floor have the following dimensions. 



That for the gallery or passage, has a chord or span of 10 ft., a 

 rise of 1 ft. and a thickness at the crown of 4i in. The three arches 

 which support the three rooms of this floor are each 17 ft. 4 in. in 

 span, witli a rise of 3 ft. 3 in., and a thickness of 10 in. at the crown. 

 The roof of the building is formed by two semicircular arches, one 

 covering the granary already mentioned and the other covering the 

 gallery. The principal of these arches has a span of 20 ft. 3 in., 

 with a thickness of 10 in. at the springing and G in. at the crown. 

 The smaller arch over the gallery is 10 ft. in diameter, with a thick- 

 ness of G in. at the springing, and of only 3 in. at the crown. 



The beton was generally composed in the following proportions — 

 One part of lime slacked by immersion; 

 One part and a half of pure sand ; 



And two parts of gravel or broken flints, from 3 to 5 in. in di- 

 ameter, according to the thickness of the walls in which they were to 

 be employed. Thus the largest stones were used for the thick ex- 

 terior walls, those of smaller size for the large arches, and the smallest 

 of all for minute arches and ornamental mouldings on the outside. 



The beton was in the first place well mixed up by hand labour, and 

 then thrown into a framework or encaissement in regular courses of 

 lft. in thickness. This encaisement was simply composed of a few 

 uprights, to which were secured horizontal planks placed on edge one 

 above the other at the proper distance apart, so that when removed, 

 the beton filled in between them shall occupy the proper thickness 

 required for the wall. This method of raising the walls in courses 

 of about 12 in. deep, appears to have been practised by the ancients 

 in building with beton. The system will be quite familiar to those of 

 our readers who have even witnessed the building of mud or earthen 

 walls, as practised at this day in the Lyonnois and other parts of 

 France, in the eastern countries, and in a ruder form even in this 

 country and in Ireland. The arches for supporting the floors were 

 turned upon centres of the usual kind, and the exterior mouldiogs in 

 front of the house consist of beton filled into moulds prepared to re- 

 ceive it. A thin layer of lime mortar was plastered over the exposed 

 surfaces of the walls. This plastering was pointed to a sharp arris at 

 all the exposed edges, and seemed to give to the whole structure an 

 appearance of smoothness and regularity which could not be expected 

 from the naked beton. 



In the summer time the beton of one course was generally suffici- 

 ently set in six hours to admit of the next course being filled in, and 

 about twelve hours were required in spring time. As each course 

 was regularly completed throughout over the whole area of the walls, 

 the part which had been first filled in was commonly set by the time 

 the course was finished, so that no delay took place on the completion 

 of the separate courses. The centres for the arches of the gallery 

 were struck at the end of a month after its completion, and those of 

 the large arches were removed at the end of two months and a half. It 

 was found that after this interval the beton had acquired so much 

 consistency as to produce no thrust upon the abutments. 



The exterior surface of the front wall, and the outside of the great 

 arch which forms the roof, were painted with several coats of oil 

 paint. This was done as much for the purposes of decoratiou as to 

 enable the surface to withstand more perfectly the rain and frosts of 

 the succeeding winter. It was found afterwards, however, as far as 

 durability was concerned, this precaution was unnecessary, for those 

 parts which had not been covered with paint, perfectly resisted all 

 the rigors of the most severe seasons. | 



Not only has M. Lebruce, the architect who constructed this build- 

 ing, declared its perfect condition, after the lapse of two years, but he 

 has accompanied a report, which he addressed to the Societi- d' Encou- 

 ragement, with certificates from the prefect of the department of Tarn 

 and the sub-prefect of the arrondissement of Gaillac, both of which 

 attest the perfect solidity of the building, and state that it presents all 

 the appearance of stone. In order to try the strength of one of the 

 arches supporting the principal floor, it was loaded three months after 

 the centres were struck, with a mass of earth 10 feet ki thickness, and 

 extending over the whele top surface of the arch. The weight thus 

 applied amounted to 1250 lb. per square foot, or about eight times as 

 much as that which a floor supports when a room is full of people, 

 aud this weight was borne without the slightest injury to the arch. 



The great economy of this method of building is highly important. 

 It appears that the cost of the whole work was no more than 5s. 'id. 

 per cubic yard, which is about one-third the price of brickwork in 

 that part of France. 



It may be necessary to explain that the process of slacking lime by 

 immersion, which is mentioned in a former part of this description, is 

 performed in the following manner. The lime stone, after being 

 burnt, is taken from the kilu and placed in a pan in pieces from the 

 size of a walnut to that of an egg. The pan is then plunged for a 

 few seconds into water, and withdrawn as soon as the lime begins to 

 emit heat. After this operation, the lime continues to heat and swell 

 and falls at length into powder. It is placed in this state in chests or 

 casks, where the heat being concentrated, and a great part of the 

 moisture being condensed and not allowed to escape in steam, will be 

 again taken in by the lime which is then more perfectly slacked than 

 otherwise. If the lime is intended to be kept any time before being 

 used, the chests or casks should be covered with straw and placed in 

 a perfectly dry place entirely removed from any danger of being 

 penetrated by any kind of moisture. 



(To be continued.) 



ARE SYNCHRONISM AND UNIFORMITY OF STYLE] 



ESSENTIAL TO BEAUTY AND PROPRIETY 



IN ARCHITECTURE? 



An Essay to which tvas not awarded the medal of the Institute. 

 By a Student. 



The question whether synchronism and uniformity of style are es- 

 sential to beauty and propriety in architecture, is so novel, that it 

 might have been well had the Institute of British Architects accom- 

 panied their proposition by some definition of the terms in which it is 

 conveyed — or at least set some limit to the sense in which they are to 

 be understood. 



Of all the arts and sciences, none has ever been, or must necessa- 

 rily be, more strongly affected by the inexorable course of circum- 

 stances, than architecture. None has been found more essential to 

 the civilized existence of mankind. None has contributed more to 

 the comforts of the humble, to the grandeur of the mighty, or to the 

 gratification of the refined perceptions of those blessed with taste. 

 None has so perfectly attained the combination of the useful and the 

 beautiful. Since aichitecture assumed the conditions of an art, hu- 

 man genius has beeu on the stretch in every period and in every com- 

 munity, to bend its capabilities to existing manners and circumstances, 

 and to study the modifications dictated by climate, by religion, by 

 the comparative progress of the sister arts, by the state of me- 

 chanical science, and the minor effects exercised by soil aDd the 

 choice of materials. 



That architecture, practised during a long succession of ages, and 

 modified by these and many other influences, moral and physical, 

 should have exhibited the most opposite extremes in style, seems a 

 necessary condition of its existence as an art. If, therefore, by syn- 

 chronism and uniformity is to be understood the strict adherence, at 

 the present period and in the locality of Great Britain, to any style 



