Many are ready, when listening to the inventor, to belittle and deny his achievements so that he will no longer be heard in honourable places, but after some months or a year, they use the inventor's words in speech or writing or design.

To disclose too much of one's inventions and achievements is one and the same thing as to give up the fruit of one's ingenuity.

Do not share your inventions with many; share them only with the few who understand and love the sciences.

We must not show to all and sundry the secrets of the waters flowing in ocean and river, or the devices that work on these waters. Let there be convened a council of experts and masters in mechanical art to deliberate what is needed to compose and construct these works.

I propose to build for eternity.

The gifts given to us by God must not be relinquished to those who speak ill of them and who are moved by envy or ignorance.