[reefer] 



PRESIDENTIAL ADDRESS 



27 



THE GIANT. 



The illustration shows the most improved pattern in " giants/' in 

 v.'hich the horizontal movement is around a bolt, made of the best 

 quality of steel and thoroughly annealed, which holds in position the 

 two cast-iron sections connecting the wrought-iron feed and discharge 

 pipes. The vertical movement is provided for by a globe joint connect- 

 ing the discharge pipe with the uppermost of the cast iron sections. 

 The nozzle is cast iron attached by a screAV thread, removable at Vv'ill, 

 as nozzles of various sizes are made to fit the same '•' butt " on any giant. 



The nozzles range from six to ten inches in diameter, and Mi-. 

 Tlobson says : — '' A small stream, six to seven inches, is more effective 

 in cutting down the banks ; and a large stream of eight, nine or ten 

 inches is the most effective for removing the caved gravel into the 

 sluices." The balance box is essential and is never omitted in giants 

 of any size. The giant is anchored to the floor of the hydraulic pit as 

 shown in the sketch with the addition of side posts at the end of the 

 wooden bed piece in order to prevent a side movement. The greatest 

 force is a thrust, by impact, of water at the angle, and if the giant can 

 be prevented from moving at the forward thrust it will generally remain 

 in place. Care must be taken to secure solid ground for the fastening 

 posts, and in wedging the bulkheads at the front and at the ends of 

 the '• giant " bed piece, in order to withstand the enormous pressure 

 from a discharge of fifty to seventy-five cubic feet of water per second 

 under a head of several hundred feet. The discharge at the nozzle is 

 very close to the theoretical in good machines connected by large pipe 



