n. Its original decoration consisted of tablets of
colored marble, the effect being similar to that of a sequence of
narrow pilasters. This original decoration has later been changed for
another. Above the chief cornice which crowns this story, and at the
same time terminates the circular walls, rises the cupola, divided
into five stripes, each of which contains twenty-five "caskets"
beautifully worked and in excellent perspective. In the center at the
top is an opening, forty feet in diameter, through which the light
enters the building. Near this opening a fragment has been preserved
of the bronze ornamentation which once seems to have covered the whole
cupola. Even without these elegant decorations the building still
excites the spectator's admiration, as one of the masterpieces of
Roman genius.

Obelisks were in Egypt commemorative pillars recording the style and
the title of the king who erected them, his piety, and the proof he
gave of it in dedicating those monoliths to the deity whom he
especially wished to honor. They are made of a single block of stone,
cut into a quadrilateral form, the width diminishing gradually from
the base to the top of the shaft, which terminates in a small pyramid
(pyramidion). They were placed on a plain square pedestal, but larger
than the obelisk itself. Obelisks are of Egyptian origin. The Romans
and the moderns have imitated them, but they never equaled their
models.

Egyptian obelisks are generally made of red granite of Syene. There
are some, however, of smaller dimensions made of sandstone and basalt.
They were generally placed in pairs at the entrances of temples, on
each side of the propyla. The shaft was commonly ten diameters in
height, and a fourth narrower at the top than at the base. Of the two
which were before the palace of Luxor at Thebes, one is seventy-two
feet high, and six feet, two inches wide at the base; the other is
seventy-seven feet high, and seven feet, eight inches wide. Each face
is adorned with hieroglyphical inscriptions in _intaglio_, and the
summit is terminated by a pyramid, the four sides of which represent
religious scenes, also accompanied by inscriptions. The corners of the
obelisks are sharp and well cut, but their faces are not perfectly
plane, and their slight convexity is a proof of the attention the
Egyptians paid to the construction of their monuments. If their faces
were plane they would appear concave to the eye; the convexity
compensa