The Arizona sentinel., 1900-05-02
The PothOIes Dredger.


 have been let by Crosby-Ehrich Syn
 dicate of Colorado Springs to w. T..
 Uric of Kansas City. The latter's
 representative will arrive in Yuma
 about the 10th of this month. The
 contract for the specially cut lumber
 was secured by the Yuma Lumber
 company who are having 1t cut in
 Oregon. The lumber will arrive the
 latter part of this month.
 The Crosby-Ehrich Syndicate now
 have in successful operation mining
 dredges in Idaho and Montana. The
 character of the dredges to be con-
 strpcted are essentially the same as
 their other dredges. They own in the
 Potholes country about 2,500 acres of
 land susceptible of being dredged.
 According to them, this ground is
 better than other ground upon which
 they are now operating fer the follow III lCdSOhS' bG OSN 4OSh
 is jess scanned and is nearer smooth;
 there are no unusually large boulders; the gravel disintegrates rapidly and is easily washed; the aurefrous graved exceeds in value fifty cents to the cubic yard. Hence, as soon as the first dredge has been completed the work of construction upon two more will be commenced. This subsequent expan- sion of course, depends primarily upon the issuance of favorable recom- mendation by the corps of i've experts who are at present actively engaged in prospecting for a working loc&tion for the additional mining machines. These prospectors will remain con- tiguOus to Yuma during the entire summer.
 The dredge upon which work will soon be commenced will be con tructed on the river bank at the foot of Gila street. The hull will be 30 feet beam, no feet length and have death ot , feet. When fully loaded and in work ing order the vessel will draw between 24 and 90 inches of water.
 Beginning at the bow and extending aft distance Of B feet will be we'll or recess in which the ladder and buckets will be operated. This ladder is 72 feet in length and admits of dredging at depth of 36 feet below the surface of the water. Around the ladder is a continuous chain of buckets working upon two tumblers. The upper tumbler and shaft weighs $500 pounds. On each end of the shaft is a spocket wheel each one of which weighs 3,OO0 pounds. The two boxes, upon which the tumbler shalt rests, weigh S10 pounds each. The lower tumbler and shaft weighs 5000 pounds. Each open link, between buckets weighs 4l6 pounds. In addition each ldler weighs $50 pounds or a total of $500 pounds. Each bucket and the link to which it is fastened, weighs l,l5O pounds and has a capacity of four cubic feet.
 The contract for this dredge calls for an average capacity each 24 hours, including all accidents, and lost time of 1000 cubic yards. Under ordinary circumstances, therefore, the capacity should be 4,0O0 cubic yards per day.
 Upon the barge will be 8 steam engines, seven of which are directly required for the dredging operations. The eighth engine furnishes power to complete electric light plant.
 The pulling power of 9 single bucket is equal to 2,l00 horse power which is derived by gearing from the engines. Steam Is derived from locomotive boilers which under 80 pounds pres sure would develope steam equal to 80 horse power.
 All the engines and machinery is directly controlled and operated from 5he pilot horse and will run night and lay. One pair of locomotive engines with cylinders 12x16 are required to handle the ladder and its various .,t
 The gravel is carried up the ladder and is dumped into a revolving cylin- lrical grizzley 4 feet in diameter and 10 feet long. The grizzley is perforated with numerous holes one and one-half u inches in diameter. The finer gravel and gold goes through this revolving sieve while the coarser material Is Jumped on the tailing pile 15 feet directly in the rear and on the same line on each side of this central point. The fine gravel and gold falls upon { table under the grizzly. This table is IA feet long by 20 feet wide. From the table the gravel goes to the sliuce ( Ooxes, % inches wide and S4 feet long. The boxes have Hungarian and Cari- poo rifles. The grade of the boxes can be changed at will, as necessary requires.
 Water for the grizzly and cluice i ooxes Is obtained from one 1O-inch pump and two ielting OumD that flow & inches of 10otor