In the past, the miller had to pay close attention the speed at which rotation took place and if needed, adjust the speed. Over time, a governor system was adopted, which applied a brake if the speed increased beyond a fixed limit. This enabled the miller to free up time to devote to other activities around the mill. There was an addition of a powered (I think diesel) drive for the times that the wind power was insufficient.
The gear teeth meshing with the circular cogs means that engaging and disengaging is smooth and wear related to entry and exit is lesser. Eventually there is wear of course, but then the miller only needs to rotate the circular cog by about ninety degrees and the same worn out parts are good to go, once more!
|camera||Canon EOS 7D Mark II|
|exposure mode||program mode|