on the Progress of the Useful Arts. 17!5 



at this reproduction of one machine by another, would lead us 

 to believe that handicraft is but little concerned in the forma- 

 tion of accurate instruments ; and that the operations of ma- 

 chinery possess an exactitude far higher than can be obtained 

 from the workman"'s skill. A deeper reflection will, however, 

 conduct us to very different results. The method of making a 

 flat surface by hand-work is incomparably superior to any other, 

 so that the planing engine must be considered as originally de- 

 duced from hand-labour. The divisions of the teeth of wheels 

 were also originally hand-work, and even yet the more precise 

 astronomical instruments are divided by hand. Linear divisions 

 also are better done originally than copied by any machine; and 

 thus the formation of an accurate screw, which requires the com- 

 bination of equable linear and angular motions, comes like- 

 wise to be considered as the product of human skill. Good an- 

 gular and linear divisions, an accurate planing machine, and an 

 equable screw being once obtained, it is indeed easy to form 

 others of nearly equal value ; but it must be noticed, that all the 

 imperfections of the originals are transferred to their copies, and 

 that nothing but a sagacious arrangement of the work, and a 

 skilful variation of the parts, can prevent these instruments from 

 degenerating. In this way we may regard all the finer ma- 

 chinery of our country as having originated from the careful 

 workmanship of some few primary instruments ; which, deterio- 

 rating by use, have been preserved of a proper degree of pre- 

 cision by the continued exercise of patience and of skill. 



But the formation of the machinery is not all — the provid- 

 ing of the materials is a point of as great importance : and here 

 again we are led into the same round of processes, and find that 

 each art, as at present practised, depends on the practice of the 

 same art in a ruder state. Thus the iron mine is wrought by 

 means of iron tools, these were obtained from other mines by 

 the help of other tools, and we trace up the parentage of each 

 pick-axe and shovel to the rude stone chisel, itself constructed 

 by means of some other, until we reach the first finder of a sharp- 

 edged stone ; and while we boast of the power and precision 

 that have now been attained, we must own our obligations to 

 the rude processes of uncivilized man. No set of processes run 

 so far back as those connected with the manufacture of iron, and 



