260 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[July, 



tion ; ami certainly tlie suljiect we are speaking of conies far more within 

 the provinte cif an architect, than some of the studies so fantastically insisted 

 upon by Vitruvius as indispensahle to the education of one. 



How far a knowledge of it may be useful or not must, in a great degree, 

 depend upon the peculiar walk in his profession, which an architect takes up ; 

 a man whose practice lies chiefly in building bridges, or prisons and poor- 

 liouses, can, of course, shift very well without it ; wliile it is, on the con- 

 trary, of almost paramount iiui>ortaiice to those who are called upon to erect 

 or alter residences for the opulent and luxurious ; at all events, if they, in- 

 stead of applying to it themselves, cboose to commit that department of de- 

 sign to decorators and others of that class, it is ven- \mreasonable, on the 

 liart of the profession, to att'ect to liold a coutem))tuous opinion of such per- 

 sons and their taste, when they miglit rescue their art from the baleful in- 

 fluence of sucli taste, by taking that department of it, as far as design is 

 concerned, into their own hands. There is room, however, for suspecting 

 that few of their own body would do very much better, for the simple reason 

 that such branch of design forms no part either of their professional education 

 or their after-studies : of colours, as applicable to their art, on which so much 

 depends in this comparatively trifling branch of it, if so they choose to con- 

 sider it, they know scarcely any thing. 



In tlip.se remark.*! there is but too much truth ; and among those 

 whicli we afterwards meet with there is also much that merits to be 

 considered. 



How much depends upon colour alone is obvious enough from the fact, tha* 

 the same design will appear altogether ditferent, according as it happens to be 

 differently coloured. Nevertheless, the choice of colours, and the aiTange- 

 ment of them, are generally left to the chapter of accidents. The architect's 

 eye is not trained to colouring, as connected with embellishment ; on the 

 contrary, his attention is exclusively confined to moilels that afford scarcely 

 any thing that is immediately ajiidicable to interior emhellisluncnt, unless it 

 be in a few particular cases. His books furnish him with no ideas on the 

 subject ; since what they oft'er, connected with it, rarely amounts to more 

 than an occasional section, exhibiting only one wall of each apartment, while 

 even that little is exhibited without colour, and without any of those acces- 

 sories which there must be in the rooms themselves. As mere sections, we 

 do not blame driiwiiigs of that class ; all that we mean to obsene is, that 

 their deficiencies ought to be su])plied by others. Yet even works, which are 

 professedly intended to be studies of decoration, generally leave us quite in 

 the dark as to one very material point, for very seldom, indeed, does it 

 happen that they are illuminated ; in regard to colour, therefore, they afford 

 no information. 



We must not be too liberal of our extracts, for were we to copy 

 from it as much as we could wish, we might as well transfer the whole 

 article entire to our own pages, which would be being more liberal to- 

 wards our readers, than just towards the publisher of the Foreign 

 Monthly. We must tlierefore pass over some other descriptions of, 

 and remarks on, several of the modern Parisian shops, and confine our- 

 selves to what is said of the mode in which the interior of many of 

 them are decorated. 



If less striking on the score of mere novelty, the specimens of interior de- 

 corations in shops are more successful : in fact, they exhiliit more of taste 

 than of decided novelty, except as regards the actual application, all par- 

 taking, more or less, of the style of painting in vogue at Pompeii. Milletot's, 

 the confectioner's shop, plates 4!) and .'JO, is an exceedingly pleasing example 

 of this mode of embellishment ; tasteful in design and rich in eflfect, although 

 the colours employed are little more than lirowns and greys upon a white 

 ground. Plate 66, a linendraper's shop, No. 29, Place de la Bourse, is, al- 

 though very different from the jirecediug, another agreeable subject. The 

 Cafe Gaulois, Rue Poissonnicre, is a more ambitious disjjlay of the Pompeian 

 style ; but, as that plate is uncoloured, it is impossible to form any idea of 

 that upon which the effect mainly depends. For purposes where mere general 

 effect is required, this mode of decoration may very eligibly be adopted ; but 

 it is not very favourable to other species of art, because it excludes framed 

 pictures, with which it would very ill agree, even were spaces for their re- 

 ception provided for before-hand in the design ; while it is hardly to be 

 wished that suliject pictures should be made to combine with it, by being 

 similarly painted on tlie walls themselves, because it is our opinion that, were 

 such practice to be brought into vogue, it would tend to deteriorate art by 

 giving cun-ency to a flimsy, meretricious style — a sjiccious, sliewy mannerism 

 —and nothing more. We are now taking into view the consequences, sup- 

 posing it were to become the fashion among those who occujiy not family 

 mansions but rented houses, to encourage such jiictorial embellishment on the 

 walls of their rooms. As such paintings coulil not be removed, and could 

 scarcely have value as available property, it is hardly to be supposed that real 

 talent would ever he employed in jirodiicing them, liesides, a superior col- 

 lection of i>ictures may be formed by degrees ; but, in this case, an entire 

 series would have to be paid for at once, and, if not of first-rate quality, of 

 such quality, at least, as to stand the test of critical examination as works of 

 art, and would be no better, perhai)S some degrees worse, than the same sur- 

 face decorated with simply ornamental figures ; if merely for the reason that 

 it would lune more pretension, yet be unable to support it. 



Of purely decorative painting, applied to the w»lls and ceilings of rooms; 



examples are here furnished from a ball and billiard-room, executed, at Paris, 

 for Baron Rothschild, in 1820, by Picot and Gosse. The ceiling of the 

 second-mentioned apartment, in the style of the baths of Titus, is ricli, yet 

 chaste and harmonious, and many of the other parts, taken by themselves, 

 show much taste, yet how far the tout-ensemble may be satisfactory, can only 

 be guessed at ; even allowing it to lie so, it is questionable whether it is one 

 that can safely be recommended for general purposes. It is certainly one that 

 calls for much previous consideration and foresight as to its results. It is one 

 (hat may be canied too far, and which is liable to great abuse, unless it be 

 jiut under the check of correct artistical juilgment and feeling. Still we 

 could wish to see it encouraged to a certain degree in this countiT, were it 

 only because our ai-cliitects would then, almost of necessity, be led to bestow 

 more attention than they at present do on what tiiey ought to understand; 

 and, if jiroperly taken up, it would tend greatly to widen the scojie afforded 

 to design. 



Theory, Practice, and Architecture of Bridges. Tlie Theory by James 

 H.\NN of King's College, and the Practiceil and jlrchitectural Trea- 

 tises by William Hosking, F.S.A., &c. Part 1, 2, 3. London, John 

 Weale, 1839. 



The three parts before us are devoted to a miscellaneous collection 

 of well engraved plates of several bridges of importance, which have 

 been erected in this country, in addition to what we have before no- 

 ticed, there are eight plates of the Hutcheson Bridge at Glasgow, 

 which exhibit not only the construction, but also the progress of the 

 work, the setting of the centres, building the foundations, and the im- 

 plements employed. There are several good examples of Iron Bridges, 

 constructed by the Butterley Company, and various bridges of stone 

 and timber. 



In the letter-press we have a translation of Gautliey's Treatise on 

 Bridges; but notwithstanding that this treatise has been held in higli 

 repute by many scientific men, we cannot for our part concede to it 

 such a prominent position. We consider the formulae to be generally 

 complicated, and not at all calculated to benefit the practical bridge 

 builder. The translator has fallen into a few errors in the translation; 

 the word pile has been introduced in several places for the word pier, 

 and there are some others which the scrutinizing eye of the profession 

 will discover. 



The two papers on the theory of Bridges, by Professor Hami, 

 and on the theory of the arch, by Professor Moseley, are well written 

 and of deep research ; it would have been better if the two papers 

 had been blended and intrusted to one author, for they in some 

 measure interfere with each other, and are likely to confuse the 

 student; notwithstanding, they are well deserving of an attentive peru- 

 sal, and we shall give an extract from the paper by Professor Moseley, 

 to enable our readers to form an opinion of the work for themselves. 



* * As the simplest case of a section of variable inclination, let its plane 

 be supposed always to pass through the same horizontal axis. This case includes 

 that of the circular arch under its most general form, and to this case my 

 further researches have been Umited. 



1 have snjiposed certain forces to be applied to one extremity of a structure 

 thus intersected, and resting by its other extremity upon an immoveable base. 

 As for instance a semi-arch, fig. 2, resting by its extremity B upon its abut- 

 ments, and supiiorted by a given force P, ajiplied to the key-stone AD, instead 

 of the pressure of an opposite semi-arch. On this hypothesis the equation to 

 the line of resistance may be completely determined in respect to an arch of 

 equal voussoirs subjected to any variety of loading. Mitli a view to this 

 general determination I have first supposed the loading to be collected over 

 a single point X of the semi-arch ; and on this hypothesis I have found the 

 equation to the line of pressure in terms, of the inclination of the joint .\D 

 of the key-stone (that is, of the line CD) to the vertical, the angle .\CB of 

 the segment of the arch, the common depth AD of voussoirs the point of 

 application, and the magnitude of the force P and the weight X. This deter- 

 mination eviilently includes the cases of the loaded Gothic and segmental 

 arches; and were the magnitude and point of application of the force P 

 known, it would constitute a complete determination of the equihbrium of 

 the structure. 



But unfortunately, in the actual case of the arch, this pressure upon the 

 key is an unknown tiling. We neither know its point of ajiplication nor its 

 amount. 



It is the pressure of the opposite semi-arch, or rather it is the resultant of 

 an infinity of pressures exerted by the opposite semi-arch upon an infinity of 

 points, by wliicli that semi-arch is in contact with the face AD of the key; 

 and the amount of this resultant, and whether it pass through the middle of 

 the key-stone or its extremities, are necessary, but, up to this period of the 

 investigation, unknou'n elements of the theory. Some other principle of me- 

 chanical action manifestly enters into the conditions of the equilibrium, and 

 claims a place at this period of the discussion. 



That other principle is this, that of all the pressures which can be applied 

 to the key, different in their points of appUcation and amount, but all con- 

 sistent with the equilibriimi of the semi-arch, that which it actually sustains 



