What type of old engine is this

[zimmy]

Any combustion chamber, spark plugs, or magnito or anything? I would say it is not an engine at all based on the picture. Looks to me like it is belt driven, probably by a hit and miss engine. The belt pulley drives the big gear on the left and the gear drives the shaft that drives the pistons. Compressor might be right. The pistons might drive air into that cylinder on posterior side. I may have a home for it if you decide to get rid of it.