198 SCIENCE IN GRECO-ROMAN ANTIQUITY 



medes is accurate, it is solely because it is based on 

 an intuitive empirical statement, namely that the 

 effective power of a force at a given moment is equal 

 to this force multiplied by its distance from the 

 vertical axis which passes through the fulcrum 

 Fd=pV (Fig. 36). 



Fig. 36. 



This relation, which is based on the moments of 

 forces, was not clearly formulated until the end of 

 the Middle Ages ; it is equivalent, in a horizontal 

 position, to the relation P/ = p~L ; it was by this 

 that Archimedes was instinctively guided. 



As we have seen, from a desire for lucidity he con- 

 fined his theoretical researches to statics, that is, to 



