It is observed of Archimedes, by his philosophical biographer Plutarch, in the Life of Marcellus, 

 that " although we might labour long without success in endeavouring to demonstrate from our own 

 invention, the truth of his propositions ; yet so smooth and so direct is the way by which he leads us, 

 that when we have once travelled it, we fancy that we could readily have found it without assistance, 

 since either his natural genius, or his indefatigable application, has given to every thing that he 

 attempted the appearance of having been performed with ease." 



