in the theory of value and prices. 



61 



So also the rods maintain a constant money rate for exchange; in- 

 stead, however, of the former simple relation between the producers 

 and consumers there is now the following that the sum of the ordin- 

 ates of A I^, and A I^, equals the ordinate of AI^, and likewise for 

 II, III, etc., also that the thickness of the back cisterns of A^ plus 

 that of Ag equals that of A^. These results are effected by parallel 

 rulers, those for the former purpose being represented in fig. 1 V. 



The new machinery required for the exchange process consists 

 then (1) of triplicate pistons* which necessitate that the same 

 quantity of A shall be produced, exchanged, and consumed ; (2) the 

 additional rods and levers (horizontal and inclined) to make the 

 marginal disutilities of producing and exchanging proportional to 

 the recompense and which also maintain a constant price for exchang- 

 ing the same thing ; and (3) the special contrivance to add the 

 marginal disutilities of producing and exchanging for any individ- 

 ual so as to equal that of consuming, and also equate the sum of 

 the prices of producing and exchanging to that of consuming. 



§ 2. ANALYTICAL. 



A^.,+ ...-fA^.,=rA^,i+ ... + A^,„=A^,,+ ... +A^,„ ] 2 m 



\ 



equations. 



3 mn 



M,, + . . . + M^,„=M,, + . . . -f- M^,„=M^, + . . . + M^,„ J unknowns. 



K,n Pa,. + . . . + M^,„ p^^^ + KnPa,, + • • • + M^,„ i^«.e = ^K.n Pa,. + . . • + ^.,nP,a,. 



n—\ independent equations. 3 m new unknowns (prices). 



S-r "'^■■> 



dlJ_ 



dA~ 

 dV_ 



(IA~ 



= F(A„,) ; . 

 = F(A„,) ; . 







3 mn equations. 

 3 mn new unknowns 

 (marg. ut.). 



* The income and expenditure-pistons are merely duplicate as before. 



