Andrew meikle (1719 – 27 november 1811) was an early mechanical engineer credited with inventing the threshing machine, a device used to remove the outer husks from grains of wheat. , painting by a. Reddock (floruit 1800). See source website for additional information. Object Type: painting. Genre: portrait. Date: 1811. Dimensions: height: 125.4 cm (49.3 in) ; width: 100.3 cm (39.4 in). Medium: oil on canvas. Depicted People: Andrew Meikle. Collection: National Portrait Gallery. Andrew Meikle by A. Reddock