General Information

Serial #

N/A

Part Number

1

Total Parts

1

AKA

N/A

Patents

N/A

General Description

ferrous metal stand, casing, disk, handle/ synthetic handle grip

Dimensions

Note: These reflect the general size for storage and are not necessarily representative of the object's true dimensions.

Length

35.0 cm

Width

20.0 cm

Height

43.2 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Physics

Category

Demonstration & teaching equipment

Sub-Category

N/A

Manufacturer

AKA

Chicago

Country

United States of America

State/Province

Illinois

City

Chicago

Context

Country

Canada

State/Province

Ontario

Period

1920s+

Canada

This piece of equipment was used at the Chatham Collegiate Institute in Chatham, Ontario, a secondary school which was founded in 1885 and closed in 2003. In 1851 the first school was established in the village of Chatham and by the late 1870's it was called Chatham High School. In 1885 the school attained the status of a collegiate institute, enabling it to obtain larger provincial grants and by 1887 a new school building had been constructed and the CCI was considered to be one of the most outstanding secondary schools in Ontario (it was destroyed by fire in 1946). In 1940 a new building was completed & again was considered to be one of the most modern educational facilities in the province. The school was closed in 2003.

Function

An instrument used to demonstrate the fundamental laws of optics such as the paths of incident & refracted or reflected rays, including through lenses & prisms.

Technical

An example of a Milvay optical disk (for optics demonstrations) made by the Chicago Apparatus Co., circa 1920-1930. Three slits in one side allow the paths of the beams to be traced through various shaped optical elements – convex, concave, prisms, etc. The angles of deviation could be measured on the scale in order to calculate the density and refractive index of the optical element. Milvay was a trade name of Chicago Apparatus. Co. The disk is illustrated in the 1929 cat but not the 1936 catalogue. See also an illustration of Central Scientific Co's version, the Hartl optcial disk which appeared in the 1923 catalogue (Ref. 3).

Area Notes

Unknown

Details

Markings

cast lettering on base reads ""CHICAGO", "APPARATUS", "COMPANY"/ white lettering on disk reads "CHICAGO APPARATUS COMPANY/ MANUFACTURER/ RESULT GIVING SCIENTIFIC INSTRUMENTS/ CHICAGO, ILL."

Missing

appears complete

Finish

painted glossy black with white painted disk

Decoration

gold lining on casing