A tractor driver and Iowa State Professor J.B. Davidson looking at an Iowa integrating and recording traction dynamometer, mounted on the linkage between the tractor and the piece of farm machinery being pulled. The farm tractor has rubber tires. The…
A tractor driver and Iowa State Professor J.B. Davidson looking at an Iowa integrating and recording traction dynamometer, mounted on the linkage between the tractor and the piece of farm machinery being pulled. The farm tractor has rubber tires. The…
A horse-drawn farm freight wagon full of husked corn on a gravel road. Seen from behind, the driver has turned to look at the camera. The rubber-tired wagon is being pulled by a two-horse team.The background countryside suggests very late fall or…
A horse-drawn farm freight wagon full of husked corn on a gravel road. Seen from behind, the driver has turned to look at the camera. The rubber-tired wagon is being pulled by a two-horse team.The background countryside suggests very late fall or…