The good opinion of mankind like the lever of Archimedes with the given fulcrum moves the world.

The simplest schoolboy is now familiar with truths for which Archimedes would have sacrificed his life.

He was thinking alone and seriously racking his brain to find a direction for this single force four times multiplied with which he did not doubt as with the lever for which Archimedes sought they should succeed in moving the world when some one tapped gently at his door.