side wings, which is occupied by the library and lecture rooms, and which joins the fourth wing at the back. This fourth wing contains the work-rooms, store rooms and the rooms of the staff, and communicates directly with the two wings in which is the main exhibition space. The Director's offices are approached by a separate door. The lecture room is thus directly accessible to the public without entering the exhibition galleries. At the back of the lecture hall is a room for the use of the lecturer. The seats are arranged as in a theatre, on the sloping floor, the stereopticon being placed about at the centre of the room on a stand which can be automatically raised and lowered. The lecturer stands upon a platform in front of which runs a long table. Beneath this table the lecturer finds electric buttons which control the shutters at the windows on the sides of the hall. By pressing one of these buttons the metal curtains at the windows are lowered practically without noise and with no effort. Another switch controls the lights, and still a third one the blackboard, which drops like the curtains in Greek and Roman theatres, into a socket in the floor. The stereopticon is a double one and is arranged so that two slides can be thrown on the screen at the same time, thus making it possible to compare very readily two types of material.
