102
GOLD MINING IN GEORGIA.
sand-pump for raising gravel from the channel excavation, but this was later on abandoned in favor of a hydraulic gravel elevator. The substitution was made for economic reasons as well as for the fact that the latter had in its favor greater simplicity, more constant work, and easier portability, as well as greater facility of installation.
This elevator is the design of Mr. W. R. Crandall, the general manager of the Chestatee Company. It combines cheapness and compactness of construction, and a novel feature is the introduction of air at the nozzle whenever the inlet of the suction-pipe is entirely submerged. Its mechanism and operation have been admirably described and illustrated in a paper by Mr. Crandall, presented at the Pittsburgh meeting of the American Institute of Mining Engineers in February, .1896. AVe believe that this form of elevator may have quite an extended and useful application in many parts of the Southern field, and in order to intelligently bring it before those of our readers to whom the Transactions of the American Institute of Mining Engineers may be inaccessible, we cannot do better than to repeat the descriptive portions of Mr. Crandall's paper,1 changing the numbers of the figures to suit this report:
"Fig. 13 shows the elevator in detail; Fig. 1-t, the manner in which it is set; Fig. 15 the details of the flume, etc. In all the figures the parts are lettered respectively as follows :
A. Cast-iron elbow at the base of the elevator.
B. Wings or vanes, to straighten the water before it enters the nozzle.
C. Nozzle.
D. Air-cap.
E. Air-inlet pipe, to furnish air when the bottom of the discharge-pipe is submerged.
F. Studs to support the discharge-pipe and to keep it and the nozzle in line.
G. Cast-iron Hanged throat. H. Discharge-pipe.
I. Discharge-box.
K. Hood for discharge-box.
L. Adjustable wood-packing around discharge-pipe.
51. Discharge-flume.
N. Adjustable flume-supports.
This elevator, as used at the Chestatee mine, near Dahlonega, Ga., where it has been gradually developed and perfected under the needs of practice, consists essentially of an elbow, A, longer at one side than the other, and coupling by means of a flange to a 5-inch pipe. At the other extremity are a flange, into which the nozzle screws, and three studs, F, which support the throat into which the gravel and water enter to be elevated. The throat slips inside the C-in. lap-welded pipe, H, for discharging into the flume on the bank, from which it may be conveyed wherever desired.
The whole apparatus, except the discharge-pipe, may be readily carried by two men. If it be necessary to move the elevator often, to keep up with the drainage, the portable character of the outfit is a great advantage.
At the Chestatee mine the practice is about as follows: The water-supply is conducted to the mine through a 9-inch pipe. At a suitable point the water is divided, and a 5-inch pipe conveys that used by the lift, while a 7-inch pipe conducts to the giant. Valves are provided at the Tee, so that one or both
1 Trans. Am. Inst. Eugs., xxvi, 1897, pp. 62-68.
