General Information

Serial #

N/A

Part Number

1

Total Parts

7

AKA

Spectrum Line Measuring Comparator

Patents

N/A

General Description

Metal casing, chassis and parts/ Glass screens/ Synthetic screen, controls, cable coverings, parts

Dimensions

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

Length

102.0 cm

Width

76.0 cm

Height

84.0 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Astronomy

Category

Research

Sub-Category

N/A

Manufacturer

AKA

Grant

Country

United States of America

State/Province

California

City

Oakland

Context

Country

Canada

State/Province

Ontario

Period

Unknown

Canada

An instrument used at the David Dunlap Observatory at the University of Toronto, one of Canada's most important astronomical observatories. The David Dunlap Observatory opened in 1935 as the result of a bequest from the wife of David Dunlap. The telescope was a 74 inch (188 cm) reflector built by Grubb Parsons of Newcastle-upon-Tyne in England. The 74 inch was then the largest telescope in Canada (surpassing the 72 inch telescope of the Dominion Astrophysical Observatory in Victoria) and became the second largest in the world after the 100 inch Hooker Telescope of the Mt. Wilson Observatory outside Los Angeles. DDO's reputation grew and following WWII, it began to graduate most of the astronomers produced in Canada with University of Western Ontario far behind. Beginning in the 1960s a number of other astronomy departments were created but UofT/DDO held its place, a position it probably still holds. The DDO had a good technical staff which gave them an advantage and, with most of the 1940s to early 1970s top astronomers coming from UofT, grants from NRC and then ENSERC were almost guaranteed and allowed UofT's top astronomers -- Hogg, van den Berg, Fernie, Bolton, Kamper, Martin, etc. to acquire or build some of the best equipment available in university observatories. For optical observatories, only the DAO had technical staff and budgets that surpassed those of DDO. In 2007, citing increasing light pollution, the University of Toronto announced plans to sell the Observatory property. In June 2008, it was sold to Corsica Development Inc., a subsidiary of Metrus Development Inc. and the Observatory was closed. In 2009 the Observatory buildings and 80% of the site were designated a cultural heritage landscape. Also in 2009 Corsica and the Royal Astronomical Society of Canada, Toronto Centre announced an agreement allowing the RASC to provide public education and outreach programs at the observatory, and to operate the 188 cm telescope.

Function

An instrument used in astronomy to measure spectral lines from plates usually taken with spectrographs on a telescope.

Technical

An example of an instrument used to measure spectral lines from plates, largely, though not exclusively, taken with the spectrographs on the 74 inch telescope at the David Dunlop Observatory.

Area Notes

Unknown

Details

Markings

Black lettering on grey plate on front reads 'Spectrum Line Measuring Comparator/ GRANT INSTRUMENTS INC./ 5812 COLLEGE AVE./ OAKLAND, CALIFORNIA'/ Brushed meal plated with incised black lettering for control functions/ Incised black lettering on controls/ Green labels read '2./ OIL DAILY WHEN IN REGULAR USE' and '3./ DO NOT USE WITHOUT PROPER INSTRUCTION'/ Typed note on back reads 'THE GRANT HAS BEEN OVERHAULED AND READJUSTED SO THAT/ AS OF THIS DATE (NOVEMBER 1, 1972). IT IS IN VERY GOOD/ SHAPE/. THE OVERHAUL REQUIRED THAT SOME FUNDAMENTAL CHANGES BE MADE IN THIS MACHINE. THEREFORE, AS OF/ THIS DATE (1.11.72), NO ONE IS CHECKED OUT ON THIS MACHINE AND NO ONE MAY USE THIS MACHINE UNTIL CHECKED OUT/ BY TOM BOLTON./ WHEN YOU ARE CHECKED OUT YOU WILL BE ADDED TO THE NEW LIST/ IN THE LOG BOOK./ EXPERIENCED USERS ARE FERVENTLY REQUESTED NOT TO MAKE/ HAPHAZARD ADJUSTMENTS. NEW DETAILED INSTRUCTIONS WILL BE/ PREPARED SOON. UNTIL THEN, WHEN IN DOUBT CONSULT/ TOM BOLTON (BY PHONE IF NECESSARY.)'

Missing

Unknown

Finish

Grey painted casings and parts/ Black painted parts/ Brushed metal chassis and parts/ Plated parts/ Black synthetic controls/ Grey and black synthetic covered cables/ Green synthetic screen in black painted housing/ Colourless transparent glass sheet in black painted metal frame and glass screen

Decoration

N/A