Midway between the two red mosques rises a majestic pile of pure white marble 186 feet square, with the corners cut off.  It measures eighty feet from its pedestal to its roof, and is surmounted by a dome also eighty feet high, measuring from the roof, and fifty-eight feet in diameter.  Upon the summit of the dome is a spire of gilded copper twenty-eight feet high, making the entire structure 224 feet from the turf of the garden to the tip of the spire.  All of the domes are shaped like inverted turnips after the Byzantine style.  Four small ones surround the central dome, exact duplicates and one-eighth of its size, and they are arranged upon arches upon the flat roof of the building.  From each of the eight angles of the roof springs a delicate spire or pinnacle, an exact duplicate of the great minarets in the corners, each sixteen feet high, and they are so slender that they look like alabaster pencils glistening in the sunshine.  The same duplication is carried out through the entire building.  The harmony is complete.  Every tower, every dome, every arch, is exactly like every other tower, dome and arch, differing only in dimensions.

The building is entered on the north and south sides through enormous pointed arches of perfect proportions reaching above the roof and at each corner of the frames that inclose them is another minaret, a miniature of the rest.  Each of the six faces of the remainder of the octagon is pierced by two similar arches, one above the other, opening upon galleries which serve to break the force of the sun, to moderate the heat and to subdue the light.  They form a sort of colonnade around the building above and below, and are separated from the rotunda by screens of perforated alabaster, as exquisite and delicate in design and execution as Brussels point lace.  The slabs of alabaster, 12 by 8 feet in size, are pierced with filigree work finely finished as if they were intended to be worn as jewels upon the crown of an empress.  I am told that there is no stone work to compare with this anywhere else on earth.  Hence it was not in Athens, nor in Rome, but in northern India that the chisel of the sculptor attained its most perfect precision and achieved its greatest triumphs.  All of the light that reaches the interior is filtered through this trellis work.

The rotunda is unbroken, fifty-eight feet in diameter and one hundred and sixty feet from the floor to the apex of the dome.  Like every other part of the building, it is of the purest white marble, inlaid with mosaics of precious stones.  The walls, the pillars, the wainscoting and the entire exterior as well as the interior of the building are the same.  You have doubtless seen brooches, earrings, sleeve-buttons and other ornaments of Florentine mosaic, with floral and other designs worked out with different colored stones inlaid on black or white marble.  You can buy paper weights of that sort, and table tops which represent months of labor and the most exact workmanship.