" That art on which a thousand millions of men are depend- 

 ent for their sustenance, and two hundred millions of men ex- 

 pend their daily toil, must be the most important of all ; the 

 parent and precursor of all other arts. In every country, then, 

 and at every period, the investigation of the principles on 

 which the rational practice of this art is founded, ought to 

 have commanded the principal attention of the greatest minds." 

 — James F. \V. Johnston. 



