=Mosaic Decorations of the East Corridor.=--The various trophies already spoken of as ornamenting the mosaic of the vault of the East Corridor are ten in number, each occurring in one of the pendentives, at the ends and along the sides. Below each are the names of two Americans (only those actually born in the United States being included) eminent in the art or science typified. The list of trophies, with the names, is as follows: Architecture (the capital of an Ionic column, with a mallet and chisel), Latrobe and Walter; Natural Philosophy (a crucible and pair of balances, etc.), Cooke and Silliman; Music (a lyre, flute, horn, and music-sheet), Mason and Gottschalk; Painting (a sketch-book, palette, and brushes), Stuart and Allston; Sculpture (the torso of a statue), Powers and Crawford; Astronomy (a celestial globe), Bond and Rittenhouse; Engineering (including an anchor, protractor, level, etc.), Francis and Stevens; Poetry (a youth bestriding Pegasus), Emerson and Holmes; Natural Science (a microscope and a sea-horse), Say and Dana; Mathematics (a compass and counting-frame), Peirce and Bowditch. In the vault proper is inscribed a list of names of Americans distinguished in the three learned professions: under Medicine, Cross, Wood, McDowell, Rush, Warren; under Theology, Brooks, Edwards, Mather, Channing, Beecher; and under Law, Curtis, Webster, Hamilton, Kent, Pinkney, Shaw, Taney, Marshall, Story, and Gibson. [Illustration: THE MANUSCRIPT BOOK.--BY JOHN W. ALEXANDER.] From the East Corridor, entrance to the basement may be had through a little lobby with a domed mosaic ceiling under either of the main staircases. At the north end of the corridor is the Librarian’s Room, and at the south end are a toilet-room for ladies and a cloak-room. The little lobby of the latter is especially bright and attractive, with deep, velvety red walls, a high arabesque frieze, and ceiling decorations of lyres and a disc containing a large honeysuckle ornament.