General Information

Serial #

N/A

Part Number

1

Total Parts

2

AKA

Heliostat

Patents

N/A

General Description

Metal base, body, four wheels and parts/ Glass mirror with synthetic cover/ Synthetic parts

Dimensions

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

Length

107.0 cm

Width

70.0 cm

Height

116.0 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Astronomy

Category

Observation equipment

Sub-Category

N/A

Manufacturer

AKA

Razdow

Country

United States of America

State/Province

New Jersey

City

Newark

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 astronomical instrument with a movable and a fixed mirror, used to follow the path of the sun and reflect its light into a telescope.

Technical

This coelostat was used at the David Dunlap Observatory and then loaned to the Ontario Science Centre. The lower mirror tracks the sun, then reflects it to the upper mirror and then projects the image of the sun for study/viewing

Area Notes

Unknown

Details

Markings

Blue plate with incised white lettering reads 'COELOSTAT-HELIOSTAT/ MODEL CH-250-200/ RAZDOW LABORATORIES/ NEWARK NEW JERSEY U.S.A./ Gold lettering on attached control box reads 'CH-250/ COELOSTAT-HELIOSTAT' and for control functions

Missing

Unknown

Finish

Glossy white painted base, body, control box, parts/ Coated glass mirror with colourless transparent synthetic cover/ Gold coloured brass parts/ Plated and metallic parts/ Black synthetic knob/ Multicoloured wire coverings in transparent synthetic tubes, one with metal and synthetic control box at end/ Black cord covering and connectors/ Red light on control box

Decoration

N/A