Notched-Rib Churn: A Solid S-Winged Dasher Turns Inside Upright Ribs Whose Notches Alternate, Crossing the Cream's Currents

"The action of these alternately placed spaces and rib projections is such that the cream is forced, in intermingling and crossing currents, around the inside of the churn body, thereby greatly increasing its agitation and intermingling more air therewith."

Use a 20-litre food-grade bucket as the body A. Cut eight hardwood ribs 20 mm wide and 300 long, tapered so their inner faces stand upright 117 mm from the centre against the bucket's sloping wall (about 20 mm deep at the foot, 30 at the top). Cut five notches m 30 mm long and 12 deep in each, on 60 mm centres, starting 15 mm from the foot on four of them and 45 mm on the other four, whose last notch runs out at the top. Screw them inside from outside (screws l), 20 mm above the floor and an eighth of a turn apart, the two patterns alternating, and seal the screw holes.

Glue up hardwood into a block 260 mm tall and cut it to the plan of Fig. 2: a round hub 56 mm across with two wings curving the same way round, 30 mm thick at the hub tapering to 12 at the tips, reaching 108 mm from the centre. Bore it 16.2 mm through the centre and pin it on a 16 mm stainless shaft f 325 mm long, its foot 5 mm below and the dasher 20 mm above the floor. File the shaft's top 15 mm square, 11 mm across the flats.

Cut a 12 mm HDPE cover I to the bucket's top with a 26 mm hole in the middle. Screw two hardwood ears a 30 x 40 mm, 105 long, to opposite sides of the bucket's top, standing 45 mm above its rim. Cut a hardwood cross piece B 370 x 140 x 25 mm, notched at its ends to drop over the ears, bored 8.4 mm across through ears and ends for stainless pins b, and bored 16.6 mm at the centre. Screw two hardwood bearing blocks C 50 x 25 x 108 mm on B, one 60 to 85 mm in front of the centre and one 25 to 50 behind, bored 16.6 mm across 83 mm up. Run a 16 mm stainless shaft d 125 mm long down through B and the cover with the socket g pinned on its foot and the pinion E pinned on its top, its teeth 30 mm above B. Run a 16 mm stainless crank shaft 180 mm long through the blocks with the wheel D pinned on meshing E, a shaft collar, and a crank G of mild steel flat bar, 100 mm throw, with a hardwood handle.

Pour about 10 litres of heavy cream at about 15 °C, checked with the thermometer, into the bucket with the dasher in, put on the cover, drop the cross piece over the ears so the socket takes the shaft's square, and push in the pins. Turn the crank so the wings' convex faces lead, timing it. When the butter comes, turn the other way a while to gather it. Pull the pins, lift off the gearing and cover, lift out the dasher, take out the butter, pour the buttermilk into a bowl, wash the butter in cold water until it runs clear, salt and weigh it.

**V. Stirewatt** of Albany, Dougherty County, Georgia, US 31,413, 12 February 1861, "Churn"; the printed text spells the name Stirewatt and the drawing Stirewalt. He claimed "the ribs, or cleats, L, L, on the inner surface of the churn body A, arranged and operating in combination with the dasher H". He allowed the notches to run the full depth of the ribs or only part of it; ours are part depth, so each rib stays in one piece. He gives the dasher's form only as Fig. 2 and does not say which way to turn for churning; we lead with the wings' convex faces. His gears were bevel wheels on an iron standard; ours are a printed crown wheel and pinion on wooden blocks. Every size here is ours.