Correspondence between John Charley and staff at James Howorth and Co. Limited, relating to the development, improvement and installation by Howorth of an air filtration plant for a sterile enclosure at Charnley’s new theatre at Wrightington Hospital [later called the Charnley-Howorth Clean Air System]. Also included is reference to testing, copies of the results of tests, diagrams, plans and extraction calculations, and details of experience with the prototype system, suction marks and vacuum pumps.
There is correspondence relating to complaints by Charnley regarding the design and installation of the ventilating plant, to the advertising campaign launched by Howorth in relation to the sterile enclosure, and an attempt by Charnley to dissuade Howorth’s from considering the demountable sterile enclosure as a commercial proposition.
There is reference to orders of equipment and discussion of materials, maintenance of the equipment and improvements to it.
Also included is discussion of the production of a second sterile enclosure in a theatre at Wrightington Hospital, and one at [the King Edward VII Hospital], Midhurst, with reference to design, maintenance, testing, and running instructions.
There is discussion of the manufacture of gowns and masks, the purchase of enclosures in North America and South Africa, and of competitors. There is also reference to air sterility standards, to Charnley’s book Low Friction Arthroplasty of the Hip, to relationships with Codman [and Shurtleff Inc.], and provision of the infection figures for 3 years of use of the Howorth enclosure.