ON THE WEALTH OF A COMMUNITY, &c. 517 



APPENDIX. 



Examples extracted from writers on Political Economy. 

 M"^ CuLLocH, 2d Edition, 193. 



Comparison of two machines, one of which lasts one year the other 

 ten years, the cost of each being £.20000, and their produce the same, 

 the ratio of profit 10 per cent. 



When r/ = ] , 



1-9'"'' 1 10 91 



^'^Y^^'^ n' ^ = C(9 + l) = C'|l= 42000. 



When r/= 10, let y and A become %f and A^, 



v' = ^~g"' = J_ 10'" _ 5 , 



•^ ^-''-l 1111"'-10"' ~ 88 "^^^^' 



A-C ^-g~' 9"-l 155 ^ , 



^ - ^ • n^-^TTT^ = 844 <^ nearly = 3672. 



If G now represent the gain to the community by employing the 

 more durable machine, 



Again, when the machine lasted 1 year there was paid in wages 

 10 

 mCy = ~ mC. When 10 years, the amount paid in the ,o* year of its 



being employed will be 



mCf + {m,k + m,{\-k)p]G = c\^^m + {mJc + viAl-k)p\^\. 



3 U2 



