Optical Diagnosis Lenses

IHPST

Accession Number: 2011.ihpst.5

Description:

248 lenses of varying thickness and concavity. They are arranged in a dark brown leather covered wooden box with an inner red cloth lining. The lenses are organized by columns as spherical or cylindrically concave, incremental diopter (D) and full length (IN). Six lenses are loose and wrapped in paper. There is a red scratch on the lid of the box with a faded manufacturer label. Each lens is of a varying thickness and the glass pieces are held in metal rings with tabs to hold them.

Alternative Name:

Primary Materials:

Box: Wood, Leather, Velvet; Lenses: Glass, Metal.

Markings:

Description of diopter and focal length (4 columns) (D./In top). 2x “spherical concave” 2x “cylindrical concave”. Center top-angled lenses-markings: 1,2,3,4,6,8,10,12,16,20,P,S,B,F,H,W,S,R.

Dimensions (cm):

Length = 7.4, Width = 51.5, Height = 30.3

Function:

Used by an optician to determine proper correcting lenses.

Condition:

Good: Leather binding is cracked and falling apart, there is a large hole in the leather on top and on the bottom right side. Lenses are in good condition, one of the loose lenses is covered in tape.

Associated Instruments:

Manufacturer: Johnston Optical Co., Detroit Michigan.

Date of Manufacture: c. 1900-1930

Provenance:

These lenses were used by Canadian Paleoantrhopologist Davidson Black (1884-1934.)They were given to Penny McLeod-Smith who used them in her high school physics optical lab.In 2011, Penny McLeod-Smith donated them to the IHPST.

Donated to UTSIC: Yes

Historical Notes:

1) Wikipedia contributors, “Davidson Black. Wikipedia, The Free Encyclopedia, (accessed February 17, 2012. Provides some information and an excellent bibliography.