ANCIENT DESEMERS OR STEELYARDS. 555 



in rt^rs. 7 ;ind s.' The Egyptian contrivance tailing the place of the 

 tongue, which was constructed of a pliniib bob and three strings, 

 answered its purpose as perfectly as the more usual linger rigidly 

 attached to the beam. Only in the horizontal position all the threads 

 are equally taut, and the slightest tilting slackens two of them. 



The introduction of the tongue was a great advance. In many cases 



Fic. (i. — From Wilkinson's Ancient Egyptians. 



it showed whether the ))alance maker understood the theory of the 

 balance. Even if he paid little attention to the friction, yet if he put 

 the axis of I'otation in the right place he could weigh pretty well with 

 his balance in spite of all its imperfection, as a balance from Bavaria 

 bch)nging to the Museum of Costumes shows (fig. 10). It is composed 

 entir(dv of wood. Even the axis of rotation is made, in the crudest 



Fjq. 8.— From Erman's Kjjypt. 



Fig. 7.— From Erman's Egypt. 



way, of a round stick. Yet it will weigh light objects pretty well, 

 because the axis of rotation is well placed. With 4 pounds in each pan 



I So reads Sr.keland's text, an<l certainly in fi^. 7 the plunil) bob seems to be hung 

 by two strings, between whicli is a little tongue fixed to the beam. The plummet 

 thus accomplishes the same purpose as the spirit level on a modern balance of pre- 

 cision, but more directly and neatly. A third cord to a plummet would be .luite 

 purposeless and un-Egvptian. The tongue between the two cords nnght be <hs- 

 pensed with, but the arrangement would be far more sensitive with it— I'r. 



