1843.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



125 



TESSELLATED PAVEMENTS, 



VNCIENT AND MOP! UN. 



[A work has been recently published, at a great expence, under the direc- 

 tion of Mr. Blashfiekl, who is connected with the old established firm of Messrs. 

 Wyatt, Parker & Co. the cement manufacturers, for the purpose of exhibiting 

 to the profession what truly beautiful patterns may be adopted in tessellated 

 and mosaic pavements, by the aid of the small porcelain squares recently 

 introduced by Mr. Biashlield for that purpose. The work consists of ten 

 elaborate designs by Mr. Owen Jones, the author of the "Alhambra," 

 splendidly printed in colours. These designs cannot fail in directing the public 

 taste to this admirable description of ornament, for the floors of halls, sa- 

 loons, conservatories, baths, &c. — we may also add the aisles of churches ; for 

 to our taste, it is far preferable to the dingy encaustic tiles. The following 

 essay on the materials and structure of tessellated pavements is by Mr. F. 0. 

 Ward who has devoted considerable research in collecting the information.] 



The object of the following notice is to call public attention to a new 

 material for tessellated pavements, and to an improved method of construct- 

 ing the same, by the adoption of which this ancient and esteemed mode of 

 decoration may he re-introduced, at a moderate cost, for the embellishment 

 of our modern buildings. The improvements in question will, it is con- 

 fidently believed, enable the modern architect to execute mosaic floorings, 

 equal in point of extent and elaborateness to the most celebrated of the re- 

 mains that have descended to us from antiquity, and very far superior to 

 these in brilliancy and variety of colouring, in the accurate co-adaptation of 

 the pieces, and in the uniform durability of the surface. 



In order to arrive at a just conclusion on this subject, it will be necessary 

 in the first place to bestow some attention on the materials and structure of 

 the old Roman tessellated pavements, as described by Vitruvius, and still to 

 be traced in the remains existing in various parts of the country, and in the 

 specimens preserved at the British Museum. 



The materials of the best and costliest pavements at Rome (such, for ex- 

 ample, as those still remaining in the baths cf Caracalla), are coloured 

 marbles of various kinds, differing considerably from each other in hardness 

 and durability. The inferior pavements, found scattered through Britain, 

 France, and other parts of Europe, and along the northern coast of Africa, 

 are usually made of such coloured stones as the neighbourhood happened to 

 supply, with the exception only of the red tessera:, which are almost inva- 

 riably of burnt clay. Thus, in the celebrated Roman pavement which was 

 discovered in 1793, at Woodchester, in Gloucestershire, the grey tessera? are 

 of blue lyas, found in the vale of Gloucester, — the ash-coloured tessera; of a 

 similar kind of stone, often found in the same masses with the former, — the 

 dark brown of a gritty stone, met with near Bristol, and in the forest of 

 Dean, — the light brown of a hard calcareous stone, occurring at Lypiat (two 

 miles from the site of the pavement) — and the red tessera?, as usual, of fine 

 brick. These materials differ from each other in point of hardness even 

 more than the coloured marbles of the costlier pavements at Rome ; and it 

 is evident that a surface composed of such heterogeneous materials must wear 

 unequally at different parts, and ultimately fall into hollows wherever colours 

 produced by the softer kinds of stone are employed. 



If this remark should be met by a reference to remains of ancient pave- 

 ments, discovered in this country after a lapse of sixteen centuries from their 

 first construction, and still retaining a level unworn surface, it is obvious to 

 reply, that the mere length of their duration gives no force to the objection! 

 seeing that, during by far the greater portion of the time, these pavements 

 have lain buried ; and, further, that even when in use they formed floors to 

 the baths and best chambers of the residences of Roman provincial governors, 

 and were therefore, doubtless, subject to very inconsiderable traffic. The 

 entrance hall of a modern club-house would afford a much more trying test 

 of durability ; and it will hardly be disputed that a pavement composed of 

 heterogeneous materials would in such a position be liable to wear unequally. 



The next point to be observed with reference to the Roman tessera;, is the 

 want of uniformity in their size and shape, and the consequent irregularity 

 of their junctures, especially in the more minute portions of the design. 

 Whoever will take the trouble to examine the choicest specimens of old 

 pavements at the British Museum (as, for example, one presented by Mr. 

 Lysons, which formed part of the Woodchester pavement referred to above,) 

 will perceive that the tessera?, instead of coming into contact by smoothly 

 ground and equal sides, are in many places separated by broad uneven lines 

 of cement. In some parts the intervals are of such width that the cement, 

 which in a good pavement should be scarcely seen, forms at least a fourth of 



the visible surface. It is scarcely necessary to point out the effect which 

 this net-work of brown cement lines, running through the whole design, and 

 mixing a muddy hue with every tint, must have in diminishing the purity of 

 the colours, and in deadening the sharpness and brilliancy of their contrast. 

 It is much as if a picture, when finished, should be crossed and re-crossed all 

 over with lines of brown paint. 



Proceeding from these remarks on the materials of the Roman pavements 

 to consider the mode of their construction, we shall find that, while the 

 effect produced was imperfect, the means employed for its production were 

 costly and inadequate to the end proposed. 



Vitruvius, in the first chapter of his seventh book on architecture, after 

 describing the manner in which the foundation of the pavement should be 

 formed, goes on to say, that on the topmost layer of cement the tessera? are 

 to be laid — care being taken to keep the surface flat and true with the level ; 

 that, in the next place, ay unevennesses and projections are to be worked 

 down by rubbing and polishing ; and that, lastly, a layer of cement is to be 

 spread over the whole and scraped oti' again (in order, it would seem, to fill 

 up any cavities in the cement between the tessera,', and to render the surface 

 as smooth as possible all over). 1 



We need not dwell at length on the time and trouble that it must have 

 taken to set each tessera separately in the cement, and to try the surface 

 with the level after every few pieces were laid. With respect to the subse- 

 quent operation of grinding down and polishing the surface of the work, it 

 must have been in most cases (and particularly where stones of a hard and 

 gritty nature were employed) the most tedious and laborious part of the pro- 

 cess. We shall presently see that all these difficulties are obviated by the 

 employment of the newly invented material and mode of construction, which 

 we will next pioceed to describe — taking, however, in the first place, a rapid 

 survey of the various experiments which preceded this invention, and of the 

 successive improvements by which it has been gradually brought to per- 

 fection. 



About forty years ago, a patent was obtained by Mr. C. Wyatt for a mode 

 of imitating tessellated pavements by inlaying stone with coloured cements. 

 Floors thus constructed, however, were found liable to become uneven in 

 use, in consequence of the unequal hardness of the materials ; which defect 

 prevented their general adoption. Terra cotta inlaid with coloured cements 

 has also been tried, and found liable to the same objection. 



During the last ten years, cements coloured with metallic oxides have been 

 used by Mr. Biashlield to produce imitations of the ancient tessellated pave- 

 ments ; and, for work protected from the weather, the material appears to 

 have answered tolerably well ; but for out -door work, required to stand frost, 

 it has been found necessary to employ Roman cement, the dark brown of 

 which gives a dingy hue to all colours mixed with it. This, with some other 

 practical difficulties, has interfered with the success of the plan. 



Bitumen coloured with metallic oxydes has also been tried by Mr. Blash- 

 field as a material for ornamental floorings. The groundwork of the pattern 

 was first cast in any given colour, and the interstices were afterwards filled 

 up with bitumen of various other shades. But this method was even less 

 successful than the former ; the contraction and expansion of the bitumen 

 soon rendered the surface uneven ; the dust, trodden in, obscured the pat- 

 tern ; and the plan, besides being ineffectual, was expensive. 



Thrf e years ago, Mr. Biashlield succeeded in constructing an extensive and 

 elaborate inlaid pavement, on the plan of the Venetian Pise floors. It was 

 made after designs furnished by 11. S. Hope, Esq., at whose country-seat 

 Deepdine, in Surrey, it was laid down. It is still in good preservation.-' 



In the same year (1839) Mr. Singer, of Vauxhall, obtained a patent for a 

 mode of forming tessera?, by cutting, out of thin layers of clay, pieces of the 

 required form, which are afterwards dried and baked in the usual way. His 

 patent also included an improved method of uniting the tessera? with cement, 

 so as to form slabs of convenient size for paving, lie has executed in this 

 maimer some very admirable mosaics, and his invention must be regarded as 

 one of the most important steps towards the revival of the art in this 

 country. 



We now come to the discovery which led to the invention of the tessera? 

 particularly referred to throughout this treatise. 



In 1840, Mr. Prosser, of Birmingham, discovered that if the material of 

 porcelain (a mixture of flint and fine clay) he reduced to a dry powder, ami 



1 This is the general sense of the passage according to the best conimen- 

 tators. The phi iseologj In the original is here very obscure and has pro- 

 bably suffered from the carelessness of e: i J transcribers. 



2 ^ flooi ufaverj similar kind was laid ilovvn al Mr. Hope's mansion, in 

 Duchess Street, abou J i ■■ ■ i i lo be still in excellent 

 condition. 



17 



