Hey, that's a classic. I've heard it called a swede saw, but more often a whipsaw.

I have one of those on the wall of my shop/barn. It's twice as deep, nearly five feet long, and the handles are missing. Some dunce threw it on the recycling pile at the local landfill, and I quickly redirected/repurposed it (slid it into the bed of my truck) in the interests of history and art.

I stand in great awe of the men who spent their days working these saws. They must have been muscled like boxers. Not the sort to trifle with while they were on a spree after a long winter in the bush ...