DOt4Ilt/ STop UP TRAVEL LINlIT/N4 CONTICOL RoO CONT,eOL leO&> .I1CrVATOR STeEL LlF=T!NG CA8L€ /Z€/JIIOTI: COIVT1!OL L€VE.e~.. .. , 5'0 PSI WATElei P/c'€SSUR.E F.eOAl/ r-'1NKS IN Rool'" SUPPORT TIMMER CONJECTUIiAL CROSS-SECTION OF A JlYDIeIlULlC ICIlM liT BOOTH'S TH£AT/C£ Fig. 15. Longitudinal cross-section of a hydraulic ram, extrapolated from the ram shown in Fig. 14. Drawing by the author. 16 WINTER, 1975 THEATRE DESIGN AND TECHNOLOGY I USITT [