Specification of Alfred Austin Usher
Subtitle: respirators
Publisher: Great Seal Patent Office
Published: 1868
Place of publication: London
Language: eng
Subjects: Respiratory Protective Devices
Notes: Cover title.

At head of title: A.D. 1868, 3rd March. No. 713.

"Alfred Austin Usher, of Compton Road, Canonbury, in the county of Middlesex Gardens".