570 president's address. 



"W. B. Clarke in 1811 ; but in 1851 the prospecting operations 

 of Hargraves drew public attention to it, and since then, up to 

 the 1st of January, 1883, according to the Annual Report for 

 1882 by Mr. Harrie Wood, Under Secretary for Mines, gold to 

 the value of £34,870,378 has been raised ; the value of the pro- 

 duction for 1882 being £526,521. 



The yield of gold for 1852 was greater than that of any subse- 

 quent year : this was due to the fact that the miners naturally 

 first gave their attention to the shallow deposits in the beds and 

 in the banks of the creeks ; thence the gold was gradually traced 

 into deeper ground and consequently became more difficult of 

 extraction. In some places it was found in the surface soil upon 

 the sides of hills, and in working this " surfacing," as it is 

 called, the gold was followed up either to the outcrop of a quartz 

 reef whence it was originally derived, or into a very waterworn 

 gravelly drift. This drift, now situated upon the side of the 

 valley and several hundreds of feet above the level of the present 

 watercourse, marks the depth of the valley at the time of the 

 deposition of the drift. And just as we should expect, seeing 

 that the valley has been gradually deepened by the erosive 

 action of rain water coursing down it during many ages, we find 

 at various levels similar old watercourse gravels, some of which 

 have been protected by coverings of basalt rock which in a 

 molten state issued from some volcanic vent, and, pouring down 

 into the valley, buried in its progress the then bed of the 

 watercourse. 



In cases where the valley had been partly filled with basalt 

 the rain water flowing over it found it an easier matter to cut 

 a new drainage channel along the edge of the basalt than 

 through it ; and so the new channel has often a very different 

 direction to the old one. Intelligent prospectors becoming 

 acquainted with these facts take these narrow tracts of basalt 

 as their guide in selecting sites for shafts for prospecting the 

 old water-course, or " deep lead." Many of the "deep leads" have 

 proved richer than the more recent riverbeds, because they contain 

 the heavy gold that had been as it were naturally ground-sluiced 



