Improvements in bi-focal lenses and their manufacture, and in apparatus to be employed in the said manufacture
By: [Malcolm Bentzon]
Contributors: Emerson, Alfred Henry, inventor; Johnsons & Willcox
Publisher: Printed for His Majesty's Stationery Office by Love & Malcomson, Ltd
Place of publication: Redhill
Language: eng
Notes: Patent specification.

Contains both the provisional and the complete specification.

Patent reference : 1904/28823.