General Information

Serial #

N/A

Part Number

2

Total Parts

2

AKA

N/A

Patents

N/A

General Description

METAL, GLASS & SYNTHETIC COMPONENTS.

Dimensions

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

Length

112.0 cm

Width

66.0 cm

Height

138.0 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Astronomy

Category

Research

Sub-Category

N/A

Manufacturer

AKA

JOYCE

Country

England

State/Province

Unknown

City

Gateshead-on-Tyne

Context

Country

Canada

State/Province

Ontario

Period

THIS INSTRUMENT PRESUMABLY USED C. 1960S+. THIS TYPE MFD 1950S-1970S, AND STILL USED IN 1990S +

Canada

PART OF A COLLECTION OF PHYSICS LABORATORY AND CLASSROOM DEMONSTRATION APPARATUS FROM MCMASTER UNIVERSITY. FOUNDED IN 1887 MCMASTER WAS ORIGINALLY A BAPTIST INSTITUTION, AND WAS LOCATED IN TORONTO. IN 1930 THE UNIVERSITY AND ITS STUDENT POPULATION OF 500 WAS MOVED TO HAMILTON, ONT. ( REF. 1)

Function

TO MEASURE THE PHOTOGRAPHIC DENSITY OF SPECTRAL LINES ON A NEGATIVE WHICH ARE TOO FAINT TO BE SEEN WITH THE NAKED EYE.

Technical

JOYCE LOEBL, BASED IN THE NORTH EAST OF ENGLAND, BUILT 1000S OF MICRODENSITOMETERS DURING THE 1950S- 1970S, AND THEY WERE SOLD AND USED WORLDWIDE. MICRODENSITOMETERS WERE THE LAST PRE-COMPUTER DEVICES FOR SPECTRAL ANALYSIS: THEY WERE REPLACED IN THE 1970S BY SCANNING DEVICES CONTROLLED BY A PDP COMPUTER. THE MICRODENSITOMETER IS CONSIDERED BY MANY TO BE THE MOST PRECISE INSTRUMENT FOR THE MEASUREMENT OF GREY SCALE ON PHOTOGRAPHIC EMULSIONS. (REF. 2)

Area Notes

Unknown

Details

Markings

NO MARKINGS

Missing

N/A

Finish

SMOOTH GREEN-GREY ENAMEL FINISH

Decoration

N/A