Casgliadau Arlein

A page containing drawings and a diagram that have been cut out and glued onto blank white paper. Includes four illustration printed in black ink, that demonstrate the Proto breathing apparatus in use and 'a diagrammatic view of the single cylinder 2-hour type "Proto" patent rescue apparatus.' The diagram has been cut out and is detatched from the rest of the page, however it is clear that it was once a part of this page. 88.98I/1 (1) - (17) were originally stored together in an acidic card file.