Propeller-Dasher Churn: A Paddle Carved From One Block Like a Ship's Screw, With Fold-Out Breakers

"These dashes or paddles are made of a single piece of wood of from 4 to 6 inches square, with length less than diameter of the churn. A hole is bored through the center ... Then saw in on either side of the shaft on the corners above and below and block out leaving sufficient bulk of timber to permit the paddles to be shaped".

Glue up a hardwood block 125 x 125 mm and 190 mm long and bore a 30.5 mm hole through its middle, across its length at the centre. Mark the hub, 60 mm across, round the hole. Following Closs, saw in on either side of the hub at the corners above and below, and chisel the waste away so two paddles are left, each twisted like a screw: about 70 degrees from level next to the hub and 38 degrees at the tip, the two turned the same way. Round the paddles to 190 mm across overall, leave them about 14 mm thick, and sand smooth.

Use a food-grade 20-litre bucket. Cut a 12 mm plywood lid 310 mm across in two halves, with a 32 mm hole at the middle and a 5 mm hole 118 mm out on each side for the wires. Screw the socket to the middle of the bucket's floor. Cut two breakers F from 12 mm plywood, 335 mm tall, 34 mm wide at the foot and 43 at the top, and hinge each by its outer edge to the bucket's wall on opposite sides, 25 mm above the floor. Bend a 3 mm stainless wire to each breaker's top inner corner, up through the lid, with a hook G on top: pull it to stand the breaker out, push it to lay it back.

Cut a 30 mm hardwood dowel 474 mm long as shaft A. Push it through the dasher until the dasher's foot is 30 mm above the floor and pin it with a screw across. Stand the shaft in its socket, put the lid halves on and fix the cog wheel on the shaft's top with an M4 screw across. Screw a hardwood upright 44 x 30 mm, 188 mm tall, to one lid half, bored 12.5 mm at 158 mm up; run a 12 mm stainless rod through it and wheel B so B meshes with the cog wheel, and fix a hardwood crank C with a dowel handle on the rod's far end.

Pull the wires to stand the breakers out. Pour in about 10 litres of heavy cream at about 15 °C, checked with the thermometer, and put the lid on. Turn the crank steadily and time it. When the butter comes, push the wires down to lay the breakers back and turn slowly to gather the butter. Then lift the lid and shaft out, pour off the buttermilk, wash the butter in cold water until it runs clear, work in a pinch of salt and weigh it.

**Jacob Closs** of Decatur, Adams County, Indiana, US 24,197, 31 May 1859, "Churn". He claimed the screw dashers with the breakers. His tub was about 12 in. across and 18 in. high and wider at the bottom; our bucket is about as wide but shallower and wider at the top. His block was 4 to 6 in. square; ours is 125 mm. The paddles' twist, the gearing and the other sizes are ours.