240 



BENJ. PIKE S, JR., DESCRIPTIVE CATALOGUE. 



So in like manner, if D had been nine times the depth of B, 

 three times the quantity of water would issue from it, 3 

 being the square root of 9. Price, $5.00. 



Fig. 261. 



. Archimedes' Screw (Fig. 261, as above) is a machine for 

 raising water ; it is represented and described as follows : 



A is a hollow pipe, coiled around a cylindrical axis ; 

 which axis is inclined at an angle with the ground, and sup- 

 ported at each end upon pivots, the upper pivot being fur- 

 nished with a handle. When this is turned round, the lower 

 end of the pipe dips into the water in the well below, and 

 turning upwards directly scoops up some of the water. 

 When the end points up, the part B will become lower than 

 it ; therefore the water will fall to B. Another half turn of 

 the handle brings C to the lowest point, and the first water 

 will occupy that part of the tube ; at the same time more 

 water will be scooped up at the end. In a number of turns 

 of the handle, equal to that of the coils of the tube, the first 

 water will reach, and flow out at the top ; and from that 

 time a flow will take place at every revolution of the 

 machine. Price, $9.00. 



Barker's Mill, (Fig. 262, next page.) This engine, as 

 represented in the annexed figure, consists of a hollow cy- 

 lindrical metal pipe, A B, of considerable height, and ter- 

 minating above in a funnel-shaped cavity. The pipe is 

 supported in a vertical position, by resting below on a 

 pointed steel pivot, turning freely in a brass box, adapted 

 to receive it ; and the upper part has a cylindrical steel 

 axis, C D, passing through a board, supported by uprights 

 at the sides. The hollow tube, A B, communicates with a 



