Rotary-Dasher Box Churn: Float Boards on Crossed Arms in a Curved Box

An up-and-down dash churn is slow, tiring work. Rufus Porter of Billerica, Massachusetts, received US 735, dated 10 May 1838, for a churn: a box eighteen inches long with a bottom curved from end to end; a wooden shaft running between a hollow cone and a pointed centre screw; two parallel pairs of rods through the shaft at right angles, carrying float boards parallel with the shaft — "what is termed the rotary dasher" — turned by a crank whose twisted tenon is pressed into the shaft and comes out when the occasion requires. This rung compares his churn's sweep with a tabletop one, then prints the dasher, builds the box, and makes butter.