Thank you all for the responses ! ! ! PAUL GAUTHIER gets the shavings for this one and DENNIS S gets some sawdust.
The man on the bottom end of the saw was indeed the pitman and the man on top was the sawyer or tiller depending on who you read. The pitman provided most of the cutting power while the team both worked to recover the saw to the upper side of the timber. The tiller man was responsible for keeping the saw on line In the first video, the fellow in the blue shirt is the pitman even though the setup is on trestles. The second video shows how laborious sawing timbers was and the captions tell of the progress and the wages for a sawyer and pitman back in the old old days.
The blog url is by STEPHEN SHEPHERD,a member here, and tells of an experience he had with a pitsaw and makes an interesting read.
FRANK ROBIE makes an interesting point about the pitman arm. It seems to me that the inspiration for that mechanical devise comes from an observation of a saw team at work. The motion of the teams arms and elbows could be seen as circular motion moving the saw in a linear manner.
Pitsawing was state of the art in the old old times and is still used in less developed parts of the world today.. Evolution as always enters the modern picture and now we have bandsaws circular saws and chain saw rigs to mill logs.
https://www.youtube.com/watch?v=q4YBOk-JN3chttp://www.fullchisel.com/blog/?p=202https://www.youtube.com/watch?v=XOp9IbqPT3k