House Patent.
This is the early version, before the tilting upper arm was introduced. While this is an important 1877 patent, the saw itself is rather rare. I haven't seen one with its treadle base.
The mechanism is in good working order. It would be driven by a small round belt. The table is not present.
James A. House, of Bridgeport CT patented the machine in 1877 and A.H. Pomeroy, in Hartford, manufactured this model as early as 1880 and also later models of the House saw


Source: American Artefacts.