This is a Hornsby & Sons Corn Dressing Machine (dress fanner).

Richard Hornsby & Sons won first prize at the 1862 Great exhibition for their corn-dressing machine.

A dressing fanner was used to clean grains. The grains were passed through a series of sieves while a fan blew away dirt and other impurities.

Dressing Fanner. Source: The Book of Farm Implements and Machines, Slight & Burn, 1858, p386.
Dressing Fanner (Source: The Book of Farm Implements and Machines, Slight & Burn, 1858, p386)