These cookies are absolutely essential for our website to function properly.
We use Google Analytics to measure how you use the website so we can improve it based on user needs.
These cookies may be set by third party websites and do things like measure how you view YouTube videos.
A blueprint of a 'Flow Diagram of Aerophor Improved Brierely Type Breathing Apparatus'. Was contained within the envelope 88.98I/1 (2) 88.98I/1 (1) - (17) were originally stored together in an acidic card file.
