176 THE STONES OF VENICE CONSTRUCTION

the use of the cusp in giving inward weight to the great pieces of stone of the flanks of the arch, and preventing their thrust outwards from being severely thrown on the lowermost stones. The effect of this arrangement is, that the whole

massy canopy is sustained safely by four slender pillars (as will be seen hereafter in the careful plate I hope to give of it), these pillars being rather steadied than materially assisted against the thrust, by iron bars, about an inch thick, connecting them at the heads of the abaci; a feature of peculiar importance in this monument, inasmuch as we know it to be

[Version 0.04: March 2008]