Do here most humbly lay this small Present at Your Majesties Royal feet. And though it comes accompany'd with two disadvantages, the meanness of the Author, and of the Subject; yet in both I am incouraged by the greatness of your Mercy and your Knowledge. By the one I am taught, that you can forgive the most presumptuous Offendors: And by the other, that you will not esteem the least work of Nature, or Art, unworthy your Observation. Amidst the many felicities that have accompani'd your Majesties happy Restauration and Government, it is none of the least considerable that Philosophy and Experimental Learning have prosper'd under your Royal Patronage. And as the calm prosperity of your Reign has given us the leisure to follow these Studies of quiet and retirement, so it is just, that the Fruits of them should, by way of acknowledgement, be return'd to your Majesty. There are, Sir, several other of your Subjects, of your Royal Society, now busie about Nobler matters: The Improvement of Manufactures and Agriculture, the Increase of Commerce, the Advantage of Navigation: In all which they are assisted by your Majesties Incouragement and Example. Amidst all those greater Designs, I here presume to bring in that which is more proportionable to the smalness of my Abilities, and to offer some of the least of all visible things, to that Mighty King, that has establisht an Empire over the best of all Invisible things of this World, the Minds of Men.