Dome

Collier's New Encyclopedia (1921)

though often used synonymously with cupola, a dome, in the stricter signifies the external part of the sense, signifies spherical or polygonal roof, of which the cupola is the internal par part. In Italian usage, however, it has a wider significa tion, being used to denote the cathedral or chief church of a town, the house (domus) par excellence, or house of God. The cause of the name of the building being thus applied to the form of the roof which covered it arose from the fact that the chief churches of Italy were at one period almost universally so roofed. It was at Constantinople and in the Byzantine provinces that the dome was first employed in ecclesiastical structures. But it was the Romans who, in reality, were the inventors of the dome, as of all the other applications of the semi-circular arch. Of their success in applying it to large buildings we have abundant proof in the ancient domes still to be seen in Rome and its neighborhood. The dome of the Pantheon is still probably the most magnificent dome in existence. The dome of St. Peter's, Rome; of St. Paul's, London; of the Capitol, Washington; and of the old Boston State House, are notable examples also. The following are the dimensions of some of the most important existing domes: Feet diam. Feet high. 143 142 Pantheon at Rome...... 116 Baths of Caracalla, Rome... 112 201 St. Sophia, Constantinople.. 115 St. Maria delle Fiore, Flor- 310 139 ence 330 St. Peter's, Rome.. 139 215 St. Paul's, London 112 220 96 Capitol, Washington 190 67 St. Genevieve, Paris.