Historic Hood River
This is a nice picture of the drag saw, not so great a picture of the loggers. This view clearly shows the mechanism to convert the rotation of the gears into the reciprocating action of the saw.
Despite its size and complexity, it must have dramatically reduced the effort to cut down a buck up a tree.
This looks like a Vaughan drag saw
See one in operation at the Great Oregon Steam up in Brooks, next to the operating steam sawmill.