GOLD. 161 



(he Amour system, where there are hirge gold mining companies with sufficient capital at 

 th(!ir disposal. Moreover, al many of the workings in the Olekminsk region the sand, gravel 

 and peat is raised and transported by means of chain gear along a Iram line. But it should 

 he observed that if tram lines, transport by endless steel ropes, and even Lartig roads are 

 met with in these regions, it is chiefly owing to the extreme dearness of horses and 

 their feed. 



The extraction of the auriferous sand is carried on simultaneously Avith the w^ashlng; but 

 in underground mines the sand is prepared for washing in the winter. Experiments made 

 on the application of the hydraulic method of exploitation have not been successful, and 

 there is not much chance of this method being ultimately adopted in the Siberian gold work- 

 ings, owing to the irregularity of the distribution of the gold bearing properties, which ren- 

 ders it impossible to erect large water reservoirs and hence of having a sufficient pressure of 

 water, AAlthout w'hich the hydraulic process is impracticable. The motive power required for 

 the machines used in the extraction of the gold is generally furnished by overshot water 

 wheels. The water is led to the washing machines either by canals or wooden conduit? called 

 s p 1 1 k a. The water supply is generally very well constructed and the timber which sup- 

 ports the conduits, in places attains 40 and 50 feet and is constructed with especial lightness 

 and strength. The supply of water to the canals and conduits is generally done by partially 

 damming the streams, and there is no need of accumulating the water in reservoir ponds, as 

 there is an abundance of running water almost everywhere. Portable engines are frequently 

 used at the gold mines of the Olekminsk region and of the system of the Amour. These 

 engines are used when there is not sufficient w^ater for the hydraulic motors. 



At the present time in Siberia, the washing of the auriferous sand on a large scale is 

 chiefly done in barrels, and only very clayey sand is treated in pans. In rare instances un<ier 

 particularly favourable conditions, when the profile of the soil is sufficiently inclined and the 

 sand easily washed, it is excavated by hand and cast into a trough in which it is washed. 

 This method, known as tlie Pakoulevsk process, is a modification of the American sluice 

 process. Mr K. Koulibin, mining engineer, has recently introduced the sluice method of 

 washing in the Urals, and he has modified Wooldear's system to suit the local conditions of 

 Siberia, a system originally projected for the hydraulic process. This class of washing appliances 

 are coming into use in Siberia wliere they are known as koulibinki. 



The first machines used in Siberia for washing the auiiforous sands, consisted of pans 

 and wooden barrels with iron fixings inside. The first pans and barrels washed from 3,000 to 

 5,000 pouds of sand per day; but when the gold industry developed they proved insufficient and 

 therefore their dimensions were enlarged and their construction perfected. All tlu^ barrels now 

 used in Siberia belong to one type and only differ in their dimensions. Each barrel consists of a 

 conical seive with one-half inch meshes. These orifices are of e(}ual size down the whole length 

 of the barrel and are distributed in a chess board fashion. Th<> barrel is made of boiler plate 

 iron about one-fourth inch thick. The inside fitting of the barrels generally consists of iron bands 

 placed edgewise. The barrels are revolved, by a special gear put into motion by hydraulic 

 motors or portable engines. The dimensions of the barrels vary from 10 to 17 feet in Ii>ngth. 

 The smaller diameters vary from ii^a to 4\'2 feet and the larger, from 4 U> 7 l'ei>t. Below the barrels 



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