CHURN. An instrument used to Sepa rate the butter out of milk. So long as the milk is alkaline the butter will not separate, but when it becomes faintly acid the butter commences to gather on the top. Agitating the milk by in troducing air hastens this by forming lac tic and acetic acids in the milk.
In 1850 Mr. Z. C. Robins of St. Louis, Mo., patented a telegraph churn, of which the following figure is an illustration.
The nature of this invention is to agi tate the cream or milk by the operation of the rotation of the beaters, (formed for that purpose) like to the action _produced. by knives for whipping eggs. The speci fication says : I produce this effect by forming the beaters on the agitator, of thin slats or boards, A A, secured to radial arms, B B, or discs, in such positions as to bring their sides at right angles, or nearly so, with the radii of the agitator. I generally construct the agitator of four series of beaters, as represented in the drawings, each series being composed of two, three or more beaters, one placed within the other, with narrow spaces be-
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tween each neater.
Unless the agitator is driven at a high velocity, the particles of milk, &c., are not thrown off tangentially. It can operate in a round vessel as well as a square one, and produces butter at the usual temperature, in about ten minutes. When the butter has been made, it is collected into a roll in the centre, by reversing the motion.
The wording of his claim is: "What I claim is the series of parallel floats or beaters A A, formed and arranged within the agitator, substantially as above described, so that when their motion is reversed, their thick inclined rear edges will gather the butter into a roll in the centre of the agi tator, substantially as herein set forth."