1842.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



251 



arm just above the wrist, apparently for the purpose of attaching 

 bracelets, and in the shoulders at tlie junction of the drapery, as 

 though a metal rosette had been affixed there. On the neck of one 

 of the Fates No. 97 (in red) are also two noles, which seem to have 

 been for a necklace. In the back of the torso of Victory No. 9G (in 

 red) are large holes, iu which it is supposed bronze wings were fas- 

 tened. No. 101 (in red) is a fragment of the upper part of the head * 

 of Minerva ; the sockets of the eyes are hollow, and were evidently 

 filled with metal or with coloured stones, and holes remain in the 

 upper part of the head, atfording the presumption that there was 

 originally a bronze helmet attached to the marble. The angles of the 

 ^gis of No. 102 (in red), which is a fragment of the statue of Mi- 

 nerva, one of the principal iigures of the western pediment, are drilled 

 with holes, by which the metallic serpents were attached, and in the 

 centre a head of the Gorgon. 



Thomas L. Donaldson, Hon. Sec. 



THE ARCH IN ARCHITECTURE, ITS ORIGIN, FORMS, 

 AND PROPORTIONS. 



The oblique arch having so prominently occupied the pages of the 

 Joiinial, there being ten papers on that subject, and only one on the 

 arch itself, by Mr. Frederick East, Vol. 2, page .354, has induced me 

 to offer a few observations. Mr. East states, on the authority of Livy, 

 Virgil, Herodotus, Ktesias, and Strabo, that, probably, the arch was 

 instrumental in the construction of the hanging gardens of Babylon, 

 built B.C. 1200; but that certainly the arch was known in Assyria, as 

 also in Lydia, which latter country was subdued by the Babylonians 

 about the period above mentioned ; and with respect to the Roman 

 works of the " Avaca maxima," said to be commenced by Tarquinius 

 Priscus, and finished by his grandson Tarquinius Superbus, "th King 

 of Rome, Ferguson in his Roman Republic, hints that they may be 

 the relics of some city previous to the erection of Rome. From these 

 authorities there can be little doubt but that the arch was in familiar 

 use at an early period, but unknown in Greece till within a century of 

 the Christian era. 



Tliis subject engaged my attention several years ago at a very early 

 age, in consequence of the prominence given to the five orders over 

 the arch, which, in my humble opinion, was worthy of a more promi- 

 nent place ; the only works known to me at that time solely devoted 

 to it, being, a treatise published in 1772, by Dr. Charles Mutton, and 

 Attwood on the constiuction and properties of arches; since that the 

 following authors have come to my knowledge :—Semple, Telford^ 

 Ware, Sraeaton, Milne ; and of foreigners, French — Perronnet, Gau- 

 thier, Borsland, Bruyere, and Belidor; and of Italians — Alberti, Pal- 

 ladio, and Serlio. First let us consider what an arcli is ; the term is 

 derived from the Latin arcus, a bow, and has been defined to be a 

 concave structure raised upon a mould called the centreing, in the 

 foim of the arc of a curve, serving as the inward support of some 

 superstructure; also as part of a circle less than a semicircle ; as a 

 hollow building raised upon a mould in the form of a semicircle ; as a 

 contracted vault ; and as an artful disposition of stones generally in a 

 bow-like form, by which the weight produces a mutual pressure and 

 abutment, so that they not only support each other and perform the 

 office of an entire lintel, but may be extended to a great width, and 

 made to carry the most enormous weights. There being no word in 

 the Greek language meaning an arch, it is inferred that the object 

 was unknown, altliough it has been said that the pediment of the 

 Greeks suggested the arch, and it has been found in the Temple of 

 the Sun, at Athens, and of Apollo at Dydamus, concealed in the walls, 

 covering the necessary openings, perhaps similar to discharging 

 arches as now used by the moderns. In sacred history the arch is 



* This fragment alone may perhaps be considered as an exception to the 

 previous siatement, that no evidei ces of colour existed <<n the statues or 

 figures of the Parthenon. The hair appears to have a red tint, which becomes 

 ilistiaclly apparent upon the application of water. 



first mentioned in Ezekiel, chap. -10, v. 16, in his description of the 

 Temple. "There were narrow windows to the little chambers, and to 

 their posts within the gate, round about, and likewise to the arches, 

 and windows were round about inwards, and upon each post were 

 palm trees." B.C. 574. The bridge over the Euphrates, at Babylon, 

 Herodotus expressly says, was built on stone piers bound with lead, 

 and lintel or squared beams of timber. The tunnels al^o at Babylon, 

 mentioned by Diodorus Siculus, were probably covered in the same 

 way. Visconti, on the authority of Plutarch, assigns the invention to 

 Alexander himself, who lived B.C. 323, or about a century after He- 

 rodotus ; Dr. Pococke thinks the Egyptians were unacquainted with 

 the arch, although Belzoni found Egyptian arches at Thebes, and one 

 at Gouinon, leading to the valley of Beban el Malook, and Diodorus 

 Siculus, in describing one of the celebrated buildings of Egvpt, takes 

 particular notice that it was tipped with one stone ; Sir John Chardin, 

 in describing the subterranean passages at Tohelminar, does not in 

 any way allude to the arch, a circumstance he would not have omitted 

 if it had been the case ; one tomb is said to be arch-roofed, but it is 

 in solid rock. 



The Romans liave the merit of being the first to introduce the arch 

 into general use. The earliest on record is the conduit at Tusculum 

 near Rome, 16 ft. wide, and 30 ft. high. The second, the theatre of 

 Marcellus at Rome, built in the time of Julius Caesar, where semi- 

 circular arches are found, and I think it may with truth be said, a 

 genuine arch did not exist prior to the time of the Romans. With 

 the remarks of your former correspondent I agree, that the arch was 

 not known in Greece, and I think there is doubt of its being used at 

 Babvlon, or Assyria, or in Rome, earlier than the time of Caesar, 

 B.C. 50. In the quotation given from Ezekiel, it appears to me that 

 the true arch is meant, as the impost was the earliest ornament in 

 arches of stone, and that, too, with leaves resembling those of the 

 palm. This would place the invention nearly .500 years previous to 

 the time of Caesar. Again, the absence of any remains is a great 

 obstacle to the latter conclusion, so that we must be content to allow 

 the merit to the Romans of bringing the arch into general use, but the 

 extent of its application was reserved for modern times, as Waterloo, 

 London, Gloucester, and Chester Bridges amply testify. 



There are the following forms of arches in use ; the date of their 

 introduction is almost as uncertain as the origin of the arch itself: — 



Tudor Arch, called after the name of the reigning family. 



Arched Dome, which arose in Etruria. 



Semi, or Roman, in exclusive use until the 12th century. 



Horse-shoe, or Moorish, more than a semicircle, found in East 

 Morgan, a building of the Anglo-Normans. 



Elliptic, first found in the tower of the Deanery of Lincoln, 1500. 



Inverted Arch, found in Cathedral of Wells and Salisbury. 



Catenarian, or Arch of Equilibration. 



Scheme or Skene, or Imperfect Arch, less than semicircle. 



Hyperbola, and Parabolic, from sections of a cone. 



Trochoid, or Cycloid, invented by Descartes, 1615. 



Epicycloid, formed by motion of a point in a paddle-wheel of a 

 steam boat, a combination of circular and progressive motions. 



Pointed Arch, first occurs in church of Friendsbury, built by Pau- 

 linus the Sacrist, 1137 ; called also the Saracenic Arch. Supposed to 

 be introduced from the Crusaders, although more probably it took its 

 rise from the intersection of two circular arches, called interlacing, an 

 example of which is in Kelso Abbey. 



There are 22 varieties, drawn from four, six, and eight centres. 



Straight Arch, or Plat Band, with joints converging to a common 

 centre, an example, Lincoln Cathedral and Greenwich Hospital. 



Vaulting or Groins, the latter arises from the intersection of the 

 former, about the Hth century. 



Rampant or Flying Arch, used to connect buttress and pinnacles 

 with the main building. 



Having stated as much as I can learn as to origin and dilFerent 

 forms of arches now in use, the most important part of the inquiry 

 remains — the proportions of the arch in its adapkition to bridge 

 building; the tiifferent forms, as circular, segmental, and elliptic, must 



