Click to go to Sirius Observatory Main PageTroughton & Simms Transit Telescope


The British company of Cooke, Troughton and Simms Ltd started with J. Troughton Sr. opening a business as an instrument maker in 1756. In 1826 the instrument business of William Simms was merged with that of Troughton. Thomas Cooke first began to manufacture refracting telescopes at York in 1836. T. Cooke and Sons Ltd purchased Troughton and Simms Ltd in 1922. Cooke Troughton and Simms was taken over by Vickers in 1924 but kept their name. In 1963 they became a part of Vickers Instruments Ltd. Cooke, Troughton and Simms Ltd went out of business in 1988. There is a lot more to the history of these companies.

Newer logo for Cooke, Troughton and Simms.

This smaller transit telescope was used by Peridier in conjunction with the 12.3" Calver telescope.

3 leveling bolts I made to replace the missing ones. They were an odd thread.

Base cleaned and painted, new cell made and installed, leveling bolts in place.

Eyepiece slid over. Note the adjustment screws for the plate underneath - it slides the same direction.

Underside of eyepiece. Notice it slides the same direction.

Picture of the lines, one set is left to right, the other sets are up & down.

New threads installed. I asked around, and found out you can use dental floss. I took extra fine watchmakers tweezers and shredded the floss. Then I took one strand and using a hot glue gun, glued one end to the platform. It dries in less than a second. If you make a mistake, it comes off easily. Then hold the line tight, and glue down the other end.

Platform in place, showing threads from the other side.

Picture showing threads viewed through the eyepiece. This was not an easy shot, as the eyepiece only has a 1/16" diameter.