Catalogue Number: 1865 (Instructions for use of) The Barrett Relative Accommodation Stereoscope Category: Papers Sub-Category: Ophthalmic product manual/instructions Corporation: R Archer and Sons Ltd Year Of Publication/Manufacture: 1950 ? Time Period: 1940 to 1999 Place Of Publication/Manufacture: London Publisher/Manufacturer: R Archer and Sons Ltd Description Of Item: Four page leaflet giving a description, method of use and interpretation of the Barrett Relative Accommodation Stereoscope with an illustration of the instrument on the front page Historical Significance: This leaflet gives the principles and instruction for use of the Barrett Relative Accommodation Stereoscope, which was designed by C D Barrett FBOA (Hons). The instrument measures relative accommodation without any change in image size as is the case when plus lenses are required. The nodal point of the eye is at the focal point of the lenses of the instrument. It is described by Barrett in the Optician of May 21, 28 and June 4 1948. It was available from R Archer and Sons for 3 UK pounds and 15 shillings. How Acquired: Ex Nathan Library Condition: Good Location: Archive office. Pamphlet and ephemera filing cabinet. Drawer 4 |