6.  Log Drivers

While we're familiar with seeing large trucks carrying logs on the road, I bet you've never seen how they used to do it!  As you see in the photo from 1917 above, men would essentially "ride" the logs down rivers to a processing plant.  

7. Aircraft Listeners

Before radar technology had been developed, the military would use very odd-looking machines like the one above in order to try to detect enemy aircraft.  They typically employed younger men who already had strong hearing skills.