The next subject is _Green_, or _The Light of Research_. The central figure is the Spirit of the Lens, which in the telescope and the microscope reveals to the scientist the secrets of the universe. She is surrounded by the sea, with its myriad forms of life furnishing her with the material for her investigations. The cherubs in one corner have a microscope. In another, they represent Chemistry; in the third Archæology (Egyptology deciphering the hieroglyphics); and in the fourth, Mineralogy--all selected as being especially concerned with original investigation and research. _Blue_ is _The Light of Truth_. The Spirit of Truth crushes the dragon of Ignorance and Falsehood under foot, and reaches to heaven for a ray of light with which to inflict the final wound. The blue of the background is the blue of daylight,--light from darkness. The cherubs hold the level, the plumb, and the Bible, each considered as an agent in indicating the presence of a universal law. The last panel represents _Indigo_ as _The Light of Science_. The figure represents Astronomy, who is guided by the soul (figured as a butterfly fluttering above her head) to explore the movement of the stars. The cherubs represent various phases of astronomical study. One of the figures, for example, explains the theory of mathematics, showing on the fingers of the hand that _one_ is the unit of everything; a second looks through a telescope; and others are studying books and making calculations. SENATE READING ROOM. At the end of the corridor leading to the House Reading Room, is a little lobby, from which one enters the Southwest Pavilion, or Senate Reading Room, reserved for the use of members of the Senate. The little lobby itself is one of the most beautiful examples of pure architectural design to be found in the Library. The walls are of Vermont marble--the same as in the corridor--panelled with Sienna marble. The moulded ceiling is finished entirely in gold, with a central rosette, surrounded by coffers and conventional Greek mouldings, one of which, a rather elaborate fret, is laid upon a ground of deep red. The whole effect of the decoration, taken in connection with the low light which prevails, is remarkably fine--a combination of great richness with soberness and refinement.