Monday 7 November 2022

The Cooke 25 inch Lens Tested

On November 5th 1867 the 25 inch object glass or lens which had been so long in the making by Thomas Cooke of York was completed. This was the largest object glass to that date. It was tested on the double star gamma 2 Andromeda and the stars were seen most distinctly divided and with the spurious disks of the three stars of the system perfectly round.

The telescope would not be completed until 1870, by which time sadly Thomas Cooke had died.







1 comment:

  1. This is the one that nearly bankrupted them and is now in Greece ?

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