1813.] 



Description of a Churn. 



Article VI. 

 Description of a Churn, By H. Robertson, M.D. 

 (With a Plate.) 



The model from which the drawing (plates 6 and 7) was 

 taken^ resembles considerably the frame of an air-pump. Its 

 base is a board of 12| inches by 9 ; from which ascend four 

 pillars in two rows, l7i inches in height; the front row is 9 

 inches distant. Those forming the back row are placed at an 

 interval of 7^ inches. These are joined together at the top by 

 cross pieces of wood, and are 5 inches separated. Upon the top 

 of the pillars there is a perpendicular wheel 7 inches in diameter, 

 with a row of pegs round the margin to the front : it turns by a 

 winch handle, projecting from the machine, and throws the 

 wheel by an axis running through a semicircular piece of wood 

 fixed upon the cross beams : 3i inches below the beam which 

 joins the tops of the pillars of the front row there is another 

 cross beam, stretching between the pillars, and which is perfo- 

 rated to admit a cylindrical piece of wood: aod between the 

 upper and lower beams there is an horizontal wheel, with per- 

 pendicular spokes ^ inch distant from each other. This wheel 

 resembles the capstan of a ship. The cylindrical piece of wood 

 which penetrates the lower beam passes through this wheel, to 

 which it is fixed, the top of it moving easily in a groove of the 

 upper beam. This cyHndrical piece of wood descends below 

 the lower beam about 6'i inches, the extremity of which has a 

 groove and a notch, that it may join with a piece of wood of a 

 corresponding form, about 10 inches in length, the lower part of 

 which is armed with four pieces of wood 2 inches long, by Ij- in 

 breadth, i inch thick, and perforated with holes. The joining 

 of the cylinder is secured by a wooden ring, made with a groove 

 to adapt it to the lower end of the notch. The lower part of 

 the cylinder descends into a barrel 7t inches deep, and in 

 diameter 7 inches. The barrel is covered by two pieces of 

 wood, which fit exactly to its brim, with a space to admit the 

 play of the descending cylinder; and that the milk in the opera- 

 tion of churning should not be dashed out. The barrel is made 

 of hard wood, hooped with brass, and is kept firm in its place 

 by a raising upon the board forming the base. 



This kind of churn is used in Spain. The Editor has been 

 informed that there is one of a similar construction driven by 

 water, that has been for some time used in Aberdeenshire, 



2 f2 



