“The materials are white marble and red sandstone.”

     “The complexity of its design and the delicate intricacy of the
     workmanship baffle description.”

Sir William continues.  I will italicize some of his words: 

“The mausoleum stands on a raised marble platform at each of whose corners rises a tall and slender minaret of graceful proportions and of exquisite beauty.  Beyond the platform stretch the two wings, one of which is itself a mosque of great architectural merit.  In the center of the whole design the mausoleum occupies a square of 186 feet, with the angles deeply truncated so also form an unequal octagon.  The main feature in this central pile is the great dome, which swells upward to nearly two-thirds of a sphere and tapers at its extremity into a pointed spire crowned by a crescent.  Beneath it an enclosure of marble trellis-work surrounds the tomb of the princess and of her husband, the Emperor.  Each corner of the mausoleum is covered by a similar though much smaller dome erected on a pediment pierced with graceful Saracenic arches.  Light is admitted into the interior through a double screen of pierced marble, which tempers the glare of an Indian sky while its whiteness prevents the mellow effect from degenerating into gloom.  The internal decorations consist of inlaid work in precious stones, such as agate, jasper, etc., with which every squandril or salient point in the architecture is richly fretted.  Brown and violet marble is also freely employed in wreaths, scrolls, and lintels to relieve the monotony of white wall.  In regard to color and design, the interior of the Taj may rank first in the world for purely decorative workmanship; while the perfect symmetry of its exterior, once seen can never be forgotten, nor the aerial grace of its domes, rising like marble bubbles into the clear sky.  The Taj represents the most highly elaborated stage of ornamentation reached by the Indo-Mohammedan builders, the stage in which the architect ends and the jeweler begins.  In its magnificent gateway the diagonal ornamentation at the corners, which satisfied the designers of the gateways of Itimad-ud-doulah and Sikandra mausoleums is superseded by fine marble cables, in bold twists, strong and handsome.  The triangular insertions of white marble and large flowers have in like manner given place to fine inlaid work.  Firm perpendicular lines in black marble with well proportioned panels of the same material are effectively used in the interior of the gateway.  On its top the Hindu brackets and monolithic architraves of Sikandra are replaced by Moorish carped arches, usually single blocks of red sandstone, in the Kiosks and pavilions which adorn the roof.  From the pillared pavilions a magnificent view is obtained of the Taj gardens below, with the noble Jumna river at their farther end, and the city and fort of Agra in the distance.  From this beautiful and splendid gateway one passes up a straight