General Information

Serial #

121561

Part Number

1

Total Parts

2

AKA

N/A

Patents

N/A

General Description

Metal casing, tube, motor casing and parts/ Synthetic controls, cable coverings, parts/ Rubber? feet

Dimensions

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

Length

45.0 cm

Width

39.2 cm

Height

20.1 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Astronomy

Category

Miscellaneous

Sub-Category

N/A

Manufacturer

AKA

Jarrell Ash

Country

United States of America

State/Province

Massachusetts

City

Waltham

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 to create a very narrow wavelength band of light to test optical filters used in photometers and related instruments.

Technical

This instrument was used primarily to calibrate the filters used in Don Fernie's photometers. Detailed knowledge of the bandpass of filters was critical for the duplication of astronomical photometric standards.

Area Notes

Unknown

Details

Markings

Plate on casing side reads 'Jarrell/ -Ash [logo]/ JARRELL-ASH CO.590 LINCOLN ST./ WALTHAM MASS. U.S.A./ MODEL NO. 82-400 SERIAL NO. 121561'/ Label on casing side reads Jarrell/ -Ash [logo]'/ Label on tube reads 'PHOTOMULTIPLIER/ TUBE SOCKET/ PRODUCTS FOR RESEARCH, INC./ DANVERS MASS./ EMI 9658-RF/ 1 KV 2.6 PA/ 3-73-85/ CATHODE ANODE'/ Label on motor casing reads 'SUPERIOR ELECTRIC/ SLO-SYN ®/ SYNCHRONOUS/STEPPING/ MOTOR/ TYPE M061-FD02 35 OZ IN' and '60 Hz STEPS 200 PER REV./ 5.0 V 1.0 A DC Hz/ SPEC BM101025 CONT DUTY/ 65°C RISE CLASS B INSUL/ IMPEDANCE PROTECTED/ THE SUPERIOR ELECTRIC COMPANY BRISTOL CT U.S.A.'/ Black lettering with white lettering for control functions

Missing

Unknown

Finish

Glossy turquoise painted textured casing/ Metallic grey tube/ Brushed and black painted metal parts/ Black synthetic controls, wire covering, feet/ Multicoloured synthetic wire covering

Decoration

N/A