Level by Thomas Street

This level is one of the largest levels that I have ever seen. I have done extensive research on the www and the only reference to Thomas Street  in the Webster Signature Database shows him operating between 1830 and 1846, which would date this level to that time period. 

Mathematical Practitioners of Hanoverian England also lists Thomas Street as an optician and mathematical instrument maker operating at 39 Commercial Road, Lambeth between 1830 and 1846.
There are numerous references and pictures of levels showing R W Street as manufacturer from about 1860 onwards.

I would imagine that RW was Thomas' son as the operating address was the same at Commercial Road, Lambeth.
The engraving on the side of the level appears to be done by hand as the copper plate engraving has inconsistencies.

The numbers on the compass dial appear to also have been done by hand as they also show inconsistencies between the same numbers.  Possibly a pantograph or similar was used.
There are two indicators attached to the long bubble at the top which I would have been used in the leveling of the instrument by marking the extent of the travel for the bubble while rotating the telescope and releveling over the foot screws.
The length of the level is 16 inches/ 41cm closed and 19 inches/ 47cm extended.
The box is in excellent condition for its age.