Notwithstanding these drawbacks, however, the Coliseum admirably answers the purposes for which it was built. It is large enough to accommodate all who will go. Its ventilation is excellent; its acoustic properties good, and its conveniences perfect as they can be. The interior is beautifully decorated with bunting, streamers, flags, and various paintings and devices. The sub-rooms, especially the reception room, are exquisitely adapted to the purposes for which they were designed. The latter room, this morning, presented a perfect wilderness of flowers, and its walls were hung with elegant paintings. Its seating capacity is, I should judge, between thirty and forty thousand, exclusive of the chorus and orchestra. The roughness and blank appearance of unfinished wood-work, has been concealed by drapery and bunting very gracefully arranged, and from one end of the Coliseum to the other, the eye is attracted by the brightest of colors. It is now my task to describe to you the opening concert, and I freely confess my inability to do so. As I write you, the deep diapason of that mighty organ, the surging waves of harmony from the largest orchestra and the marvelous sublimity of the largest chorus the world has ever known, are still in my ears, and it seems to me that I can find no words to describe it. I can feel it, but I cannot make you feel it with poor words. It almost seems a profanation to attempt it. To see that multitude alone is electrifying. It makes your blood stir within you, to look upon that great sea of faces stretching off into the distance, and to know that one man holds them in his hand, and with his little baton guides and sways them at his will. One man in that vast throng is only as one drop in the sea--one grain of sand upon the shore. His voice is indistinguishable, but the aggregate, you feel within you, will be as the on-coming of the mighty storm. Picture to yourself the scene. Immediately before you is the orchestra, one thousand strong, occupying the level platform. The brasses are at the rear, as you may easily perceive, by a strip as of gold, which runs through the sombre black, and right between them is a huge bass drum, looming up like the wheel of a steamboat. From this level platform, on three sides, rises an amphitheatre, which holds the great chorus, ten thousand strong. The sopranos are on the left, the altos on the right, and the tenors and bassos in the centre, and up from their midst rise the open pipes of the great organ, the player of which sits facing the conductor, at some distance from the organ, communicating with him by means of speaking tubes. Sub-conductors are also located near each of the choral parts, who convey the instructions of the main conductors. Just at the right of the conductor there is an electrical battery which communicates with a section of artillery at a distance. The instrumental performers are arranged in the orchestra. The first, the chorus orchestra, is made up as follows: