510 REPORT— 1887. 



the last three quantities vanishing in virtue of (49). We may therefore 

 write in this case — 



9 d!'w 



a result which must also hold good approximately when is not zero, 

 provided it be small in comparison with the other linear magnitudes 

 concerned. 



Gold and Silver : their Geological Distribution and their Probable 

 Future Production. By^UAAkisi Topley, F.G.S., Assoc.Inst.G.E., 

 Geological Survey of England and Wales, Recorder of Section G 

 {Geology). 



[A paper prepared at the request of Section F (Economics), and ordered to be 

 printed in extenso by the General Committee.] 



[Plates VI., VII., VIII., and IX.] 



Amongst the numerous causes to which the recent depression of 

 trade has been attributed that of variations in the production of the 

 precious metals is on all hands allowed to be ot" importance. Economists 

 differ as to the extent to which this variation influences prices, but all 

 will allow that it has some influence ; many believe that it is entitled to 

 the first consideration. 



It is, therefore, of interest to review the sources from which our present 

 supply of gold and silver is obtained, and to ascertain (if possible) what 

 is likely to be the supply in the near future. 



Of late years the production of gold has declined. Is it likely that 

 this decline will continue ? If so, will it be rapid or gradual ; or may 

 there be periods of oscillation in an average gradual decline ? Again, is 

 it probable that the future production of gold will be chiefly from the old 

 goldfields ; or are these, as some believe, rapidly becoming exhausted, 

 and must we look elsewhere ? 



As regards silver, for many years past there has been an increased 

 annual production and a corresponding fall in value. This fall in the 

 value of silver bears hardly upon countries where silver is the only 

 standard of currency, and is especially disastrous in India. The question 

 as to the probable future supply of this metal is therefore only second in 

 importance to that concerning gold. 



Questions of this wide character cannot adequately be treated in a 

 short paper. All that I can hope to do, and all that is expected of me, is 

 to treat the matter in general terms ; to show where, and to some extent 

 why, the supplies of the precious metals have varied in amount, and to 

 indicate, if possible, where our future supplies may be looked for. 



In place of long tables of figures, giving the yield of different countries, 

 I have constructed diagrams. These have the advantage of presenting 

 the general results at a glance, and of enabling us readily to compare one 

 country, or one set of figures, with another. It may be objected that 

 these diagrams do not give exact data ; that the produce cannot be read 

 ofi* to within a few hundred thousand pounds. To this objection it is 

 sufficient to reply that the pretended accuracy of figures given in pub- 

 lished tabular statements has but slender foundation. For our Australian 

 colonies and for Nova Scotia the yield of gold is fairly well known. 



