This tower was previously hidden under a mass of débris, which gave it a conical form like that at Nimroud. Botta had already noticed its existence, but he failed to guess its real character, which, indeed, was only divined by Place when his explorations were far advanced. As soon as all doubt was removed as to the real character of the monument, M. Place took every care to preserve all that might yet exist of it, and our [Fig. 184] shows the state of the building after the excavations were complete. Three whole stages and part of a fourth (to say nothing of the plinth) were still in existence. The face of each stage was ornamented with vertical grooves, repeating horizontally the elevation of the Assyrian stepped battlements ([Fig. 102]); the coloured stucco, varying in hue from one stage to another, was still in place, and confirmed the assertions of Herodotus as to the traditional sequence of tints.[480] The external ramp, with its pavement of burnt brick and its crenellated parapet, was also found.[481] At its base the first stage described upon the soil a square of about 143 feet each way. Each of the three complete stages was twenty feet three inches high.
Upon such data M. Thomas had no difficulty in restoring the whole building. Evidently the fourth story could not have been the original apex, as it would have been strange indeed, if, when all the rest of the Khorsabad palace had lost its upper works, the sun-dried bricks of the Observatory alone had resisted the agents of destruction. Moreover the materials of the higher stories still exist in the 40,000 cubic yards of rubbish which cover the surrounding platform to an average depth of about ten feet.
Fig. 185.—The Observatory restored. Elevation.
How many stages were there? Struck by the importance of the number seven in Assyrian architecture, M. Thomas fixed upon that number. Even at Khorsabad itself the figure continually crops up. The city walls had seven gates. One of the commonest of the ornamental motives found upon the external and internal walls of the Harem is the band of seven half columns illustrated on page [247]. Herodotus tells us of the seven different colours used on the concentric walls of Ecbatana. Finally, in assigning seven stories to the building we get a total elevation of 140 feet, which corresponds so closely to the 143 feet of the base that we may take the two as identical, and account for the slight difference between them, amounting only to about three inches for each story, by the difficulty in taking correct measurements on a ruined structure of sun-dried brick. And we should remember that Strabo tells us in a passage already quoted that the height of the great temple at Babylon was equal to its shorter diameter, an arrangement that may to some extent have been prescribed by custom.
Fig. 186.—The Observatory restored. Plan.
So far then as its main features are concerned, we may look upon the restoration we borrow from M. Place's work as perfectly authentic ([Figs. 185] and [186]). Our section ([Fig. 187]) is meant to show that no trace of any internal chamber or void of the smallest kind was discovered by the French explorers. It is, however, quite possible that such chambers were contrived in the upper stories, but we have no evidence of their existence. We may say the same of the resting-places mentioned by Herodotus in his description of the temple of Belus. But supposing that edifice to have had seven stages, its ramp must have been about a thousand yards long, and it is likely enough that halting places were provided on such a long ascent.