...The world wouldn't be the world, without trouble.

The eye - which sees all objects reversed - retains the images for some time.

The natural desire of good men is knowledge.

Every now and then go away, have a little relaxation, for when you come back to your work your judgment will be surer. Go some distance away because then the work appears smaller and more of it can be taken in at a glance and a lack of harmony and proportion is more readily seen.

A man was desired to rise from bed because the sun was already up. He replied: "If I had as far to go and as much to do as he has, I should be up by now; but having but a little way to go, I shall not get up yet."

It is an acknowledged fact that we perceive errors in the work of others more readily than in our own.

In the days of thy youth seek to obtain that which shall compensate the losses of thy old age.