"The Leaning Tower of Pisa."

Fergusson, in his history of Architecture, says: "There is perhaps no question of early Christian archaeology involved in so much obscurity as the introduction and early use of towers." They were erected long before the introduction of bells, for it is clearly ascertained that bells were not used in Christian churches until the time of Pope Adrian I., 772-795. This remarkable tower, of pure white marble, was one hundred and seventy-six years in building (1174 to 1350). It rises in eight stories to a height of one hundred and eighty-five feet, is over fifty feet in diameter, and inclines thirteen feet from the perpendicular. The lower story is a very substantial basement for the vast superstructure; its walls are 13 feet thick and 35 feet high. The six stories above this average 20 feet in height, each being surrounded by an open arcade. The whole is surmounted by a small circular tower, 27 feet in height, in which hang seven bells. The largest bell weights 12,000 lbs., and all are so placed as to help counteract, by their gravity, the leaning of the tower. The extreme summit is reached by an ascent of 330 steps, and one is well repaid for the exertion by the beautiful and extensive view which the tower commands. The long dispute, as to whether or not the inclination of the tower was intentional, has never been settled. The common opinion has been, that when the building had reached the third story the ground sank and with it one side of the tower; that the architects then planned the remaining five stories so as to throw the greatest weight upon the opposite side and thus insure stability. There is high authority for this opinion, and few of the traveling public stop long enough to investigate the opposite but much more reasonable theory of intentional inclination. That this latter is the true theory is very conclusively shown in an article in Scribner's Magazine, 1874, entitled "A Lost Art;" also in Ruskin's "Seven Lamps of Architecture," "The Lamp of Life." In both of these articles the principle of subtle architectural illusion is clearly set forth. Nor were the Pisan architects the originators of this art. Close observation and actual measurements will reveal the fact that perspective illusion was not confined to Pisa, but was practiced on a most extensive scale throughout Italy and Europe, in the Middle Ages. It was not until 1837 that the horizontal curves of the Parthenon at Athens were discovered by Mr. Pennethorn, although such curves are prescribed in Vitruvius, the only antique architect whose writings have come down to us. Pisa entertained for a long time the most intimate commercial relations with the Greek civilization of the Byzantine Empire. For eighty years of the eleventh century, from the close of which the cathedral of Pisa dates, the Doge of Pisa was also Duke of Athens. In the great Pisan buildings, then, we are dealing with Greek architecture, and the established facts, on their part, of intentional inclination, intentional obliquity, and intentional curves, to heighten architectural effects by optical illusions, make shipwreck of the theory of sinking foundations. The article referred to in Scribner points out these irregularities in the Cathedral and the Baptistery of Pisa so clearly, that the merest amateur may for himself discover, by following the lines of colored marble, that the Cathedral facade leans towards the Baptistery, and that there is a very perceptible inclination of the Baptistery itself. The Leaning Tower is therefore but an extreme phase of the Pisan irregularities in architecture, and not an immense superstructure built upon a sunken foundation, which may at any moment continue to sink and thus wreck one of the seven wonders of the modern world.

(See Pisa Cathedral.)