Note 736 — CANTO XXIX.

Twenty miles and two: The Ninth Bolgia has a circumference of twenty-two miles, and as the procession of the shades is slow it would indeed involve a protracted halt to wait till all had passed beneath the bridge. Virgil asks ironically if he wishes to count them all. This precise detail, taken along with one of the same kind in the following Canto (line 86), has suggested the attempt to construct the Inferno to a scale. Dante wisely suffers us to forget, if we will, that—taking the diameter of the earth at 6500 miles, as given by him in the Convito—he travels from the surface of the globe to the centre at the rate of more than two miles a minute, counting downward motion alone. It is only when he has come to the lowest rings that he allows himself to give details of size; and probably the mention of the extent of the Ninth Bolgia, which comes on the reader as a surprise, is thrown out in order to impress on the imagination some sense of the enormous extent of the regions through which the pilgrim has already passed. Henceforth he deals in exact measurement.