'Design of Double Houses in Blocks for Workmen & Colliers', 19th century.
© Science Museum / Science & Society Picture Library
Architectural drawings in plan, section and elevation, of semi-detached housing for mine workers. 'To economise material these houses may be built with 9 ins hollow walls'. Illustration from 'Working drawings of coal mining plant' by a Derby mining engineer, John Povey Harper, published in Leeds in the 19th century.