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THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[November, 



jection than on the front — they project nearly half their diameter; 

 the two columns on each side the arch stand on a continuous 

 pedestal. The opening of the archway is an exact square to the 

 springing of the archivolt; the entablature is one-fourth the 

 height of the column, and the attic nearly half the height of the 

 order. The whole is constructed of large blocks of Parian marble; 

 one of the stones of the cornice is 10 feet in length; the archi- 

 trave and frieze are in one block in height; the arch is composed 

 of eleven voussoirs; the blocks were originally fastened by metal 

 cramps, most of which have been removed. The archway is 

 adorned with bas-reliefs, representing the eonquests of Titus in 

 the Kast; one of these is particularly interesting, the subject 

 being the sacred utensils, candelabra, &c., belonging to the Temple 

 at Jerusalem, borne in procession at the Triumph of Titus. 



The arches of Septimus Severus and Constantine, consist of 

 three openings, the central one being the largest; they present a 

 similar facade on each front, having four detached columns, backed 

 by pilasters resting on the same pedestals as the columns. 



In the Arch of Septimus Severus, the arches communicate with 

 each other by cross openings. The detached columns have been 

 objected to, as having nothing to support, and therefore being use- 

 less; the two inner ones are not even surmounted by pilasters on 

 the attic. The statues ]daced on the entablature remove this 

 objection in the Arch of Constantine. The Arch of Septimus 

 Severus is of the Composite order, and is 76 ft. i}/ in. in height, by 

 68 ft. 2.jij in. in breadth; the columns are ten diameters in height. 

 The openings are lofty; the centre one being nearly, and the side 

 ones quite, double their width up to the springing of the arch. 

 It is richly decorated with bas-reliefs, and had formerly a triumphal 

 car on the summit, with statues of the emperor and his two sons. 



The Arch of Constantine is made up of parts carried away from 

 other structures, which the architect has not even known how to 

 apply properly. No artist was found in Rome capable of execut- 

 ing the bas-reliefs; they were therefore most inappropriately bor- 

 rowed from the Arch of Trajan, the subjects setting forth the con- 

 quests of the latter emperor, instead of those of Constantine. 

 The structure altogether presents a curious mixture of two dif- 

 ferent periods, and of the best and worst taste. Amongst other 

 incongruities it may be remarked, that the cornice of the impost 

 has both dentel band and modillions, while that of the entablature 

 has modillions without the denticulus. 



Besides the Triumi)hal Arches, properly so called, there are 

 many, eitlier simply commemorative of some person or event, or 

 serving as ornamental gates to a city: such are the arches of Gal- 

 lien at Rome, of Hadrian at Athens, and of Trajan at Ancona. 

 Speaking of the Arch at Trajan, Serlio says, "those who under- 

 stand art, are not only delighted with the adniiralile intelligence 

 shown in its construction, but render tliaiiks to the architect for 

 having produced a work by wljich our age may be instructed, and 

 may discover the rules of tlie beautiful." This arch is small, being 

 only 9 ft. U)-f^ in. in width, but lofty; it is more than twice its 

 width to the springing of the arch. On each front are four 

 Corinthian columns; it is erected on a basement; a bust of the 

 emperor is sculptured on the keystone; and the spandrils and 

 walls between the columns were formerly decorated with bronze 

 ornaments. It was built 116 a.d. 



We have now passed in review the principal public buildings of 

 the Romans; and in the next Lecture, I propose to inquire into the 

 Domestic Architecture of this great people, though comparatively 

 little is known on this subject, owing to the few remains. 



LIST OP AUTHORITIES. 

 Vitruvius— Dpcline and fall of the Roman Empire; Oibbon— Architectural Antiquities 

 of Roinej Taylor and Cresy— Les edifices antiques de R.>me; Desgodftz-Architettura ; 

 Palladio— Arcliitellura; Serlio— Kucyclopedie Melhodique— Ancient and Modern Arclii 

 lecture; Gmlliabaud— Fabbriche anliche di Roma; Cipriani— Verona lUustrata; Mattel— 

 Anuqult6i de Msmes; Clerisseau — baths of Tilus; Ponce. 



DEVONPORT MECHANICS' INSTITUTE. 



The great town of Plymouth, Devonport, and Stonehouse, is 

 well supplied by the liberality of its inhabitants with libraries and 

 institutions. We lately descril)ed an institution at Plymouth, and 

 we now bring before our readers the design for the extension of 

 the Devonport Mechanics' Institute, carried out under the direc- 

 tion of Mr. Alfred Norman, architect, practising in the town. 



The engraving shows the front towards Duke-street, which, on 

 the ground-floor, is surmounted by an entablature of the Doric 

 order, and is constructed of Portland stone. Above this ground- 

 floor are two rows of windows, the lower being smaller, and a kind 

 of base to the upper row. They are designed to give light to the 



lecture-hall and galleries. The elevation, it will be seen, is 

 terminated by a cornice, with projecting brackets and eaves roof. 

 There are three windows in the width, and the middle one on each 

 floor has three openings. On the ground-floor this centre window 

 has its openings formed by two Doric columns, the shafts of which 

 are rusticated, in correspondence with the quoins forming the 

 dressings of the side o|)enings, and of the two other windows. The 

 cornices and consoles of the lower part of the middle range of 

 windows support the balconies and balustrades of the upper range. 

 In the upper range, the middle window is converted into an arched 

 Venetian window, with the central opening of which the window- 

 head on either side corresponds, having a richly-moulded arch- 

 head and ornamented keystone. The dressings are of Portland 

 stone, and the rest of the work of limestone rubble, faced with 

 Portland cement. 



The interior contains upon the ground-floor a library, 60 feet in 

 length by 15 feet in heiglit, and which may be converted into 

 three rooms, connected by two large open arches. The end or side 

 divisions only are for books, the middle one being used as a 

 museum. f)n the ground-floor are likewise a class-room and some 

 officers' rooms. The upper floor is occupied by the great lecture- 

 hall, 61 feet by 46 feet, and .30 feet high, lighted by a double range 

 of windows. In the hall are likewise galleries. The ceiling is 

 divided into compartments by carved beams, and the walling is 

 finished with an enriched frieze, cornice, and cove. One large 

 central ventilator, and two smaller ventilators, are made orna- 

 mental. The building was finished in the spring of this year, 

 and the whole cost was about 2500/. 



Ground Plan. 

 A, Library; R, Kliiseum; C, Library ; U, Class Room; E. Parlour; 

 F, Stuircase, and Scullery under; G, Kitchen ; H, Staircase leading up 

 lu llie New Hall. 



Upper Plan, 

 CoDlaina the New Hall, with a Gallery above. The situation for the 

 Le-turer is at the Window betwe^'n the two Staircases, and that for the 

 President opposite. The part not tinted is the old building. 



