S.S. Clark mfg. 
Solid brass construction,  uses the G.W. Woodward threaded globe patent of April 5th 1864 ( this is lightly hallmarked at the top of globe )
P.J. Clark patented fount , a unique outer  sleeve allows airflow up and to the burner. 
Stamped on the fount is Clark's Patent April 14th 1863 .
Not unusual to find tin founts in their brass frames, it is correct to the maker.
This is a fairly tall dead flame at nearly 12 inches.

Condition  - fair , has been electrified at one time in its life , a soldered in patch on the chimney , and 2 holes on the backside of the lower body.
Also some of the vent holes are missing in one location near a bail rivet.
Other than that it displays nice ,  the globe unthreads with no cracks .

Price reflects its condition 

** has not been oil tested **