true and square, and is very heavy, some of the pieces weighing several tons each. The excavations for all the outer walls and piers are six feet deep. The walls commence with two feet depth of concrete. There is a round pier, fifteen feet in diameter-at the bottomat each of the four corners of the central shaft. These piers are built up to a height of twenty-eight feet and four inches above the ground line, and are tapered to form a pedestal of eleven feet diameter at the top.

There are three straight walls on each side of the central shaft, parallel with its sides, and at equal distances from each other. These walls are all joined to the round piers. The central shaft, pedestals, and walls touching the pedestals, form a square of fifty-four feet, with rounded corners. There is another wall outside of all these, nearly ten feet distant, the whole forming a square of seventy-two feet six inches. In addition to these walls, there is an oval room thirty-two and a half feet long and twenty-four feet wide, in the clear. About half of it projects from the south side, and the other half extends inward, nearly to the base of the obelisk. This room is called Memorial Hall, and is designed to be a repository for articles used by, or in any way associated with the memory of Abraham Lincoln. The interior wall is planed Illinois stone, and inside of that, a few inches, is a lining of Vermont marble in panel work, extending in dome groined arches, to form the ceiling, all supported by a series of Doric columns. This Hall is entered from the ground by a door at the south. (See Fig. 4.)

At the north side there is a similar projection, called the Vestibule to the Catacomb. It is finished inside the same as Memorial Hall, except that the floor is of black and white marble instead of Illinois stone. It is entered by a door from the north. (See Fig. 4.)

The ground plan is one hundred and nineteen and a half feet from north to south, and seventy-two and a half feet from east to west. The walls shown in Fig

ure 4 are all fourteen feet and four inches high. Arches are sprung from one to another at the top, and heavy iron beams or joists, with flanges on the lower edge, are laid across Memorial Hall and the Catacomb.. Arches are sprung from one of these beams to another, beginning on the flanges at the bottom of the iron beams. The upper part of this series of arches is brought to an even surface by filling the depressions with concrete. On top of this, embedded in cement, is a covering of immense slabs of Illinois stone, planed to a uniform thickness of about eight inches, which brings the whole area of seventy-two and a half feet square, and the half circular projections over Memorial Hall and the Catacomb, up to fifteen feet ten inches in height. Figure 5 is an illustration of this area, which is called the Terrace.

You can ascend to the Terrace by either of four flights of granite steps, one at each corner. The two on the south land over Memorial Hall, and the two at the north over the Catacomb. The flagging stone that makes the Terrace, and at the same time a roof for everything below, is laid with sufficient inclination. outward to carry off the water.

A heavy granite balustrade ascends on the outside of each stairway, and is extended so as to form a parapet around the Terrace and over the Catacomb and Memorial Hall. A small section of the parapet may be seen on each end of Figure 7.

The Catacomb now consists of five crypts, side by side, elevated three feet above the floor of the vestibule. The crypts are three feet square, and seven feet from north to south. Figure 6, is an elevation fronting north, of the five crypts as they appeared before the marble panel work was put in place. Now the central crypt is the only one visible. In it there is a marble Sarcophagus, containing all that was mortal of Abraham Lincoln.

(Fig. 6.)

ELEVATION OF THE CRYPTS.

The Catacomb and Memorial Hall are each lighted by six openings, and each opening is designed to be closed by a single piece of plate glass, when necessary.

The central shaft, being seventeen feet square at the bottom, as it rises is reduced to twelve feet square on the outside, at the top of the Terrace, and tapers to eight feet square at the apex, ninety-eight feet four and a half inches from the ground. The outside is dressed granite, and the inside hard burned brick. The shaft, or obelisk, is hollow from the terrace to the top, eightytwo and a half feet. The opening is six feet in diameter, and perfectly round. Fastenings were built in the wall, as the work progressed, for the support of a circular iron stairway, which ascends from the entrance, over the Terrace, as shown in Figure 5, and ends in a platform of iron, just near enough the cap stone to leave convenient room for standing erect. Each step is fastened to the wall by two iron bolts, the other end is attached to a central iron shaft, which extends from bottom to top. Figure 7 presents an interior view of the construction of the stairway.