<p> The continuous control of hydraulic pressure as a predetermined function of an independent variable is considered for the cases of low, intermediate and high pressure levels. A simple control system for the continuous regulation of low pressure is briefly discussed, and a means of extending its working range to intermediate pressure levels is described. Systems of this type are particularly suitable for the control of commercial diamond synthesis presses, but may also be utilised for other processes.</p> <p> A more sophisticated approach to problems of pressure generation and control is discussed in detail, with particular reference to a high pressure isostatic press. Digital computer methods of optimising the parameters of the system and simulating its response are developed.</p> / Thesis / Master of Engineering (ME)