200* TRANSACTIONS OF AMERICAN INSTITUTE. 



ience and superior accuracy, as completely answering the wants 

 of business men. 



It is of the utmost importance, however, that the scale should 

 be correct and reliable at all times, and under all circumstances; 

 a desideratum which can be attained only by the skill and expe- 

 rience of the manufacturer, and by faithful care and attention in 

 the adjustment of every part of the machine. 



The plan of construction which has been adopted by the Messrs. 

 Fairbanks appears to be correct and simple. The bearings are 

 long knife-edges, placed on parallel lines; these rest on polished 

 steel surfaces, so dressed and leveled that the knife edge bearings 

 rest equally through their whole length, and in every point; skill 

 and fidelity have obviated all tendency to derangement or wear, 

 thus securing the perfect and permanent accuracy of the instru- 

 ment, l^^ gold medal awarded. 



