State of the Useful Arts. 2C3 



the person who originated them ; and there are branches of 

 science which never could have been prosecuted, until the im- 

 proved state of the arts had placed instruments in the hands of 

 the philosopher. 



Thus all the modern brilliant discoveries in electro-magnetism 

 would have been unknown, if the manufacture of wire had still 

 been carried on by means of the forge hammer; while the 

 science of optics, and all the sciences which indirectly have bene- 

 fited by it, would have been uncultivated but for the arts of 

 glass-making aad glass-grinding ; nay, without these, that col- 

 losal collection of facts, chemistry itself, would have been — 

 to be. 



Nor are the physical sciences alone dependent on the state of 

 the arts ; Metaphysics, the science of sciences, has been affected 

 thereby ; thus the celebrated doctrine of the absolute plenum^ 

 the absurd elements of which are religiously preserved in the 

 Elements of Euclid, arose from improvements in the construc- 

 tion of geometrical instruments ; improvements sufficient to 

 bring into view the variations which take place in the dimensions 

 of solids, but insufficient to trace them to their source. 



On the exactitude attainable in workmansliip depends mainly 

 the improvement of the sciences ; and, therefore, every contri- 

 vance for the more precise construction of instruments, becomes 

 a matter of intense interest to the student of physics. What 

 prevents, at this moment, the navigator from determining 

 readily his position at sea ? — the want of an instrument powerful 

 and steady enough to bring into view the moons of Jupiter ; 

 the want of a chronometer which may beat without error. We 

 are yet ignorant of the distance of the fixed stars, and why ? be- 

 cause we have no instrument capable of reading off angles to 

 the thousandth part of a second. 



In every department of human knowledge .we experience like 

 obstructions from the want of sufficient precision. In chemistry, 

 the contested questions as to the component parts of substances, 

 arise from the inaccuracy of weighing ; from the difficulty of 

 confining the developed gases, or of examining the entire amount 

 of the products. Exactitude is indeed our war-cry against the 

 concealed intricacies of natural phenomena. 



