Will County Threshermen's Association

Wik 38.

Even certain published authors (not Reynold Wik, however) make the mistake of calling portable engines stationary engines.

Frick & Company Illustrated Catalogue (Waynesboro, PA: 1874, opposite 20.

Mid-nineteenth-century portable engines and the threshers they powered tended to be small.  Here is a Frick engine belted to a Geiser separator (thresher).