29S 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[September, 



esfimatins; hy (Iir sums total the scale of liberality on wliich tlie 

 modern public buildings of Prussia have been erected. It appears 

 that the sum of£47,S83 has been expemlerl on the new church at 

 Potsdam, £Of,S10 on the Theatre Royal at Berlin, £30,870 on the 

 School of Royal Architei'ts, &e. 



Mr. GwilCs "Observations on the Weight of Entablatures" refer 

 to the proportions between the supports and the mass supported, in 

 the orders of architecture ; and he shows a jirobabiHty that tlie jiro- 

 portions assigned by the ancients to their columns and entablatures, 

 may be founded on a principle of making the area of the mass 

 supported, taken on the geometrical elevation, equal to tliat of the 

 supports, and the voids, or intercolumniations, equal to the amount of 

 both. It is clear at first sight, that these conditions are fulfilled by 

 any colonnade, where the intervals are systyle, and the entablature 

 somewhat more than one fourth of the height of the column, propor- 

 tions which are very nearly observed in the best works of antiquity. 

 The rules laid down by Vitruvius tend to the same point, and Mr. 

 Gwilt's position is further strengthened by the actual measurements of 

 some of the ancient temples which he has compared in a table, though 

 others are rather wide of the mark. It is impossible to suppose the 

 coincidences which occur to be accidental, but they will scarcely bear 

 out a general rule, which, to be worth any thing, ought to be of general 

 application. The effect of such a law in architecture would be, to in- 

 crease the load in proportion to the diminution of the support. It is 

 obvious, that as the height of any series of supports of given diameter 

 is increased, and their strength consequently diminished, both really 

 and apparently, the intervals between them increase in area, and so 

 therefore must the superincumbent mass be increased in order to ful- 

 fil the conditions. It is true that niihin certain limits this is the actual 

 practice of the ancients. A Corinthian entablature one-fourth of the 

 height of the column, is a greater proportionate load than a Tuscan 

 entablature bearing the same relation to its support, (the intercolum- 

 niation remaining the same). This apparent anomaly has been very 

 well explained by Sir \V. Chambers, and we object to Mr. Gwilt's 

 view of the subject, only because it is too sweeping, and because we 

 think he ought to have taken the limits of the ancient practice into 

 the account. 



We do not understand th^ author's mode of dealing with the pedi- 

 ment. The diagrams on this subject require explanation ; they seem 

 to represent the entablature diminished in height until the addition of 

 the pediment makes up the required mass; but we are not aware of 

 the existence of any such practice either in ancient or modern com- 

 position. Kor can we discover by what process the voids in the por- 

 tico of the Panlheon are made cut to be equal to the solids, as stated 

 in a postscript by Mr. Cresy, especially as these proportions are set 

 down very accurately in the preceding page as l'S4 to 2-43. It must 

 be observed that Mr. Gwilt does not by any means insist upon this 

 part of the theory, but as regards the proportions between the sup- 

 ports and the weights, he considers that there is every appearance 

 of its being strictly true. 



The next paper in order is on " Lithology," or observations on stone 

 used for building; by Mr. C. H. Smith. Mr. Smith, it is scarcely 

 necessary to remind our readers, was a member of the Commission 

 appointed to survey various quarries throughout the Kingdom, for the 

 purpose of selecting stone for the new Houses of Parliament. The 

 information resulting from this inquiry has found its way to the public 

 in several shapes, but in none more likely to be of general practical 

 utility than the able and well digested performance before us. The 

 author treats principally of those extensive and useful classes of stone, 

 the sandstones and the oolites ; but we must rather call the attention 

 of our readers to the pertinent remarks which occur on the conse- 

 quences of want of attention on the part of the architect to the quality 

 of the, materials offered for his use. The effects of this negligence 

 are particularly to be noted in the metropolis, where all stone must be 

 brought from a distance, and where even the most inferior is scarce 

 and dear. Mr. Smith shows that of Portland stone, so much in request 

 in London, there are numerous shades of quality, dependent mainly on 

 the position of the bed from which it is raised, and partly from the 

 variation in the corresponding beds in different localities, and yet this 

 circumstance is scarcely ever considered in selecting the material. 

 Portland stone is Portland stone, and the architect is too ready to 

 accept it as it comes to market. 



" I have carefully looked over," says Mr. Smith, " many specifications for 

 public and private buildings, anil find the materials usually described to be 

 of the best quality ; but the general tenour of those parts describing the 

 •tone to be used rarely amounts to anything more than the mere well-known 

 name, preceded by an adjective, such as " yood Portland stone," but what 

 is to constitute that "goodness" is altogether undefined. 



" Large quantities of Portland stone of an inferior quality are brought to. 

 London, not because the island is deficient iu the best kind, hut because all 



our large buildings are executed by contracts, at so remarkably low a price, 

 that the mason's study is not what kind of stone will l)e most durable, but 

 what stone can be wrouglit by the workmen most expeditiously, and thereby 

 yield the largest profit ; and of course the proprietor of the quarries will only 

 send such stone into the market as is likely to suit his customers. St. Paul's 

 Cathedral, and many of the churches and other large buildings, erected in 

 the reign of Queen Anne, were constructed with stone very superior, as far 

 as regards durability, to the greater quantity now used ; and yet the quarries 

 from whence those sources were derived have been deserted beyond the 

 memory of any inhabitants now living at Portland ; and the only reason as- 

 signed is, because the merchants find they cannot sell such stone, on account 

 of its being a little harder, and thereby more expensive to work." 



" Abundant examples of defective Portland stone might be pointed out; but 

 when we consider tliat the stone brought from the island, good, bad, and in- 

 different, is all shipped from the same pier, which is a very small one, and 

 that notwithstanding the blocks are marked in the quarry, so as to denote 

 from whence they were obtained, it is possible that some of them may he 

 misplaced, we ought not to be surprised if occasionally a veiy had stone 

 is conspicuously placed in a building that is otherwise in excellent con- 

 dition ; and this we find more particularly to be the case in our modern 

 structures, arising no doubt sometimes from ignorance or inattention, but 

 often from some trifling interest, such as using a stone because it is just of 

 the dimensions required." 



" There are not fewer than fifty or sixty quarries already opened at the 

 Isle of Portland, most of them along the north-east and north-west cliffs, at 

 an elevation of several hundred feet above the sea. The stone from each of 

 these quarries, and from different beds in the same quarry, almost always 

 presents some minute particularities, which, on very attentive examination, 

 will serve to distinguish it from others. In many instances these distinc- 

 tions are so conspicuous as to be evident on the most casual inspection." 



Bath stone is brought to the London market under precisely the 

 same circumstances. 



" The principal quarries are at Box, Coombe Down, and Moncktou Far- 

 leigh. The stone from each of these districts, and even in the same quarry, 

 where there are generally a number of beds lying upon one another, is fre- 

 quently found to differ, in some of the minor characters, from all the rest ; 

 such as being harder, coarser, more or less durable, &c., all of which are in- 

 discriminately sold in the markets under the general name of " Bath stone," 

 and it rarely happens that an architect specifies what kind of Bath stone is 

 to be used. It is always understood that the materials are to be good, or of 

 the best kind ; and it unfortunately too often happens that the stone which 

 looks best when fresh from the workman's hand, is frequently of a description 

 most subject to premature decay. If it he left to the mason's choice, he is 

 sure to select the stone that may he most expeditiously worked." 



Bath stone finds little favour with our author, who disposes very 

 satisfactorily of the common notion that it stands better in its native 

 air than when exported to a distance. 



" The plain matter of fact is," says Mr. Smith in his plain matter-of-fact 

 style, " that the stone used in the construction of the oldest buildings at 

 Bath was procured from the Box quarries, which is in the more important 

 quaUties very superior to and far more durable than such as is now generally 

 used. The Box quarry stone is still used occasionally in and about Bath, but 

 the stone merchants in London have long since discovered that the masons 

 will not buy it on account of its being a httle coarser and harder, and thereby 

 more expensive to work." 



Two other vulgar errors on the same subject are also noticed. 

 Speaking of the decay which is already manifest in the restorations 

 of Henry VII.'s chapel, Mr. Smith observes as follows: 



" That there are many stones in the building which at present show no 

 symptoms of decomposition is readily admitted ; and those persons who 

 advocate the use of Bath stone for such highly decorative purposes, frequently 

 imagine that sufficient care has not been taken to place the stones on their 

 natural bed. The importance of such precaution is generally very contide- 

 rably overrated ; I do not consider it signifies which way a stone is fixed, 

 unless it presents a decidedly laminated structure, which scarcely ever occurs 

 amongst tlie oolites. A stone of an open, powdery, and slightly cemented 

 texture, will, if exposed to the weather, decompose in a comparatively short 

 space of time, in whatever direction it may be fixed, or whichever surface 

 may be parallel to the horizon. 



" Another generally received fallacy is the opinion that soft stone will be- 

 come hard and durable by exposure. Although this notion is true to a cer- 

 tain extent, it is not of sufficient importance to warrant its appreciation in 

 architectural works. All kinds of stone while in the rock, or when recently 

 quarried, are somewhat softer and more easUy worked than after they have 

 been exposed to the atmosphere a few months, owing to the stone in its 

 original situation being more thoroughly saturated with moisture that can 

 ever be accomplished after it has been once allowed to get dry. This is a 

 principle well known to masons, for it is a general practice amongst work- 

 men to frequently wet a stone, especially if it be rather of a hard quality, 

 during their operation of working it into mouldings or ornaments, to make 

 it work, as they term it " more kindly." If the stone be remarkably soft, it 

 is advisable not to let it dry too fast after it has been taken from the quarry. 



