Casgliadau Arlein

Printed in black ink on white paper. Includes one black and white photograph of the town hall at Zurich, and thirteen other diagrams and graphs. Three pages, one of which has become detatched. The paper 'The Practical Application of the Heat Pump' by J.B.Pinkerton, in 'The Consulting Engineer - July 1948'. Loose within a beige/light brown file containing copies of the 'Metcalf papers' and documents relating to the 'Conversion of Turbo Compressor to Electrical Drive'.