410 Dcjtripthn of 



the beam, deftined to compenfate for the very flight flexion 



of the bar, alone excepted. 



2. The apparatus, by the confrruction of the beam, is 

 balanced below its centre of motion ; fo that when no 

 weight is fufpended, the beam naturally remains horizontal, 

 and rcfumes that pofition when removed from it, as alfo when 

 the fteel-yard is loaded and the weight is at the divifion, 

 which ought to fliew how much the merchandife weighs. 

 The horizontal fituation in this fteel-yard, as well as in the 

 others, is known by means of the tongue, which rifes verti- 

 cally aboye the axis of fufpenfion. 



3. It may be difcoyered that the fteel-yard is deranged, 

 if, when not loaded, the beam docs not remain horizontal. 



4. The advantage of a great and a final! fide, (which in the 

 others augments the extent of their power of weighing) is 

 fupplied by a very iimple procefs, which accomplishes the 

 fame end with fome additional advantages. This procefs is 

 to employ, on the fame divifion, different weights. The 

 numbers of the divifions on the bar, point out the degree of 

 heavinefs expreffed bv the corresponding weights. For ex- 

 ample, when the large weight of the large fteel-yard weighs 

 eighteen pounds, each divifion it pafies over on the bar is 

 equivalent to a pound; the final] weight, weighing eighteen 

 limes lefs than the large one, will reprcfent, on each of thefe. 

 divifions, the eighteenth part of a pound or ounce; and 

 the oppofitc face of the bar is marked by pounds at each 

 eighteenth divifion. In this conft.ru6r.ion, therefore, we have 

 the advantage of being able, bv employing both weights at 

 once, to ascertain, for example, ahnoft within an ounce, the 

 weight of 500 pounds of merchandife. Tt will be fufficient 

 to add what is indicated by the final] weight in ounces, to 

 that of the large, one in pounds, after an equilibrium has 

 been obtained by the pofition of the two weights, viz. the 

 large one placed at the next pound below its real weight, 

 and the fmall one at the divifion which determines the num- 

 ber of ounces to be added, 



5. As 



