This unsigned microscope at first appears like a typical Ross bar-limb microscope, circa 1845-1855, but the fine focus controls are of a form not favoured by Andrew Ross, whose bar-limb fine control levers always operated on the nosepiece from within limb, not on the main tube, as here. The shaped limb is also of distinctive, unusual design. A stamp underneath the foot, "JD 29", led to the makers eventual identification, when a microscope of similar, but simpler form appeared on the market with the signature of the little known London maker John Dennis.

 

The microscope here is strikingly similar to the model famously illustrated and described in early editions of Jabez Hogg's On the Microscope (see image below) and that pictured next to a seated John Quekett in a famous photograph by Hogg. It's tantalising to imagine that it is the same microscope and I invite readers to make critical comparisons (comments are welcome), but it at least offers a convincing identification of the maker of Hogg's microscope.