Elliott Bros Level
Elliott Brothers traded at 56 Strand London from 1856 to 1860.
This level dates from that period.
The partnership was dissolved in 1873.
Note the small circular level vial under the telescope. I have not seen this type on any other instrument. Maybe it was an alternative to not having a striding bubble on the telescope.
Update May 9, 2017 - I have purchased a level manufactured by Cary London with a similar bubble - see under Levels elsewhere in my website.