Man has always learned from the past. After all, you can't learn history in reverse!
The centre of gravity of any cylinder is the point of bisection of the axis.
Those who claim to discover everything but produce no proofs of the same may be confuted as having actually pretended to discover the impossible.
Eureka! (I have found it!).
How many theorems in geometry which have seemed at first impracticable are in time successfully worked out!
Having been the discoverer of many splendid things, he is said to have asked his friends and relations that, after his death, they should place on his tomb a cylinder enclosing a sphere, writing on it the proportion of the containing solid to that which is contained.