DIALING. 439 



it, when they were joined together, to see what it couid 

 do. Antl I found, that in turning it moderately by tiie 

 winch, it would raise a hogshead of water in an hour 

 to the height of 15 feet. 



The universal Dialing Cylinder. 



In Fig. 1. of Plate VII. A BCD represent a cylin- 

 drical glass tube, closed at both ends with brass plates, 

 and having a wire or axis E FG fixed in the centers of 

 the brass plates at top and bottom. This tube is fixed 

 to a horizontal board H, and its axis makes an angle 

 with the board equal to the angle of the earth's axis 

 with the horizon of any given place, for which the cy- 

 linder is to serve as a dial. And it must be set with its 

 axis parallel to the axis of the world in that place ; the 

 end E pointing to the elevated pole. Or, it may be 

 made to move upon a joint ; and then it may be elevated 

 for any particular latitude. 



There are 24 straight lines, drawn with a diamond, 

 on the outside of the glass, equidistant from each other, 

 and all of them parallel to the axis. These are the 

 hour-lines ; and the hours are set to them as in the 

 figure : the XII next B stands for midnight, and the 

 opposite XII, next the board H, stands for mid- day 

 or noon. 



The axis being elevated to the latitude of the place, 

 and the foot-board set truly level, with the black line 

 along its middle in the plane of the meridian, and 

 the end IV toward the north; the axis EFG will 

 serve as a stile or gnomon, and cast a shadow on the 

 hour of the day, among the parallel hour-lines when the 

 sun shines on the machine. For, as the sun's apparent 

 diurnal motion is equable in the heavens, the shadow cf 

 the axis will move equably in the tube : and will always 

 fall upon that hour-line which is opposite to the sun, at 

 any given time. 13 * 



Note 133. It i~ evident, that if the cj Under were placed within a 



