/1; Photographs of a differential analyser. This differential analyser was made at the Building Research Station in the early 1950s. The photos (28 in total)show it in the course of construction. See MSP 135 for drawings of the machine.
/2; Lectures on Calculating Machines. Comprises: Notes nos. E137 Description of Hand Calculating Machines; E140 The Use of Hand Machines - Addition and Subtraction; E147 The Use of Hand Machines - Multiplication; E152 The Use of Hand Machines - Division; E153 Some Special Types of Calculations.