The second set of illustrations shows how Telespar was used effectively in the construction of a lighting grid for a multi-purpose theatre-classroom. Perforated square tubing was hung from the existing ceiling on 6' centers running the length of the room. Additional moveable pieces were supplied to span the 6' wide areas between members, providing mounting positions anywhere over the entire room area. The use of Telespar has proven more effective in this regard than either a channel system or plain steel pipe. In another application, renovation was required for the Main Theatre at Stanford, where for many years provisions for sidelighting the forestage area were inadequate. Two groups of three moveable "splay towers" 3' deep and 24' high with appropriate lighting slots were designed. 14 For this installation, separate frameworks of perforated square tubing were constructed with welded joints and covered with texture No. 111 plywood. Internal ladders were provided for easy access behind lighting ports. The result has provided the I ighting designer with a totally usable interior in which instruments can be mounted. THEATRE DESIGN & TECHNOLOGY IUSITT