514 



BREWING 



motion. When the axis is turned round, these arms agitato the malt in the tun, and 

 give it a constant tendency to rise upwards from the bottom. 



The motion of the axle d is produced by a wheel, x, on the upper end of it, which is 

 turned by a wheel, w, fastened on the middle of the tube b, which turns freely round 

 upon its central axis. Upon a higher point of the same tube b is a bevel wheel 0, 

 receiving motion from a bevel wheel q, fixed upon the end of the horizontal axis n n, 

 which gives motion to the whole machine. This same axis has a pinion p upon 

 it, which gives motion to the wheel r, fixed near the middle of a horizontal axle, 

 which, at its left-hand end, has a bevel pinion t, working the wheel u, before mentioned. 

 By these means, the rotation of the central axis b will be very slow compared with the 

 motion of the axle d ; for the latter will make seventeen or eighteen revolutions on its 

 own axis in the same space of time that it will bo carried once round the tun by the 

 motion of the shaft b. At the beginning of the operation of mashing, the machine is 

 made to turn with a slow motion ; but, after having wetted all the malt by one revo- 

 lution, it is driven quicker. For this purpose, the ascending-shaft / g, which gives 

 motion to the machine, has two bevel wheels h i, fixed upon a tubo/^, which is fitted 

 upon a central shaft. These wheels actuate the wheels m and o, upon the end of the 

 horizontal shaft n n ; but the distance between the two wheels h and i is such that they 

 cannot be engaged both at once with the wheels m and o ; but the tube/"^, to which 

 they are fixed, is capable of sliding up and down on its central axis sufficiently to bring 

 either wheel A or t into gear with its corresponding wheel o or m, upon the horizontal 

 shaft ; and as the diameters of no and i m are of very different proportions, the velocity 

 of the motion of the machine can be varied at pleasure, by using one or other, k and 

 k are two levers, which are forked at their extremities, and embrace collars at the ends 

 of the tube/^. These levers being united by a rod, I, the handle k gives the means of 

 moving the tube/#, and its wheels h i, up or down, to throw either the one or the 

 other wheel into gear. 



Figs, 252, 253 represent the copper of a London brewery. Fig. 252 is a vertical sec- 

 tion ; Jig, 253, a ground plan of the fire-grate and flue, upon a smaller scale : a is the close 



253 



copper kettle, having its bottom convex within ; b is the open pan placed upon its top. 

 From the upper part of the copper, a wide tube, c, ascends, to carry off the steam gene- 

 rated during the ebullition of the wort, which is conducted through four downwards- 



