Telescope, with lower insulated covering, pointed east

Telescope, with lower insulated covering, pointed east

Observatory Hill, Plaskett telescope

A picture of the telescope with an insulated blanket wrapped around the lower end of the telescope tube. The blanket was used to keep the mirror at a stable temperature. The glass uesed for the mirror was sensitive to temperature variations and the mirror would change shape as the temperature varied

Edgar Fleming

National Research Council Canada

1918