At first glance, what you might see is an armorial binding: a binding in which an owner has stamped his arms in gold tooling. No big deal, really; there are plenty of books like those in libraries. But this one is more complicated: there are TWO coats of arms, one stamped on top of the other. Here's a close-up of the center of the binding, where the arms are:
And here's the picture again with one of the two arms outlined:
A close-up of the top portion, in which you can see that there are two crowns juxtaposed and the heads of two faintly visible supporters:
Looked at in raking light, you can see that the supporter on the right looks like an antlered stag:
And the supporter on the left looks like a horse:
I can't make out the details of the arms themselves, but you can see the motto on which the supporters are standing:
My student deciphered it as "fidei coticula crux" and that looks right to me.
If you look closely at that last picture, you can see that the arms with the supporters and motto was done second: its lines cross on top of the other arms. And if you look at the original arms, you might recognize them as James I's arms: there's the harp on the bottom left of the shield, the lions and fleur-de-lis quartering the right, and the motto "honi soit qui mal y pense" circling the shield. (This gives you some sense of the arms, though that harp is a bit excessive.) (And I should point out, although it's surely obvious by this point, that I'm not particularly knowledgeable about arms and that my vocabulary choices might not be quite precise. But this is why we need help.)
So whose coat of arms is on top of James's? Is it possible it's James's favorite, George Villiers, aka the first Duke of Buckingham? According to the Burke I was looking at, not only was the family's motto "Fidei coticula crux", but he used the supporters of "a dapple grey horse" and a stag. But, as I said, I'm not super confident of my ability to deal with armorial and geneological crap, so does someone want to confirm or deny this? I'm drawn to it because if someone WAS going to stamp their arms on top of the king's, wouldn't it be great if it was him? (If you're not familiar with this period, you might want to know more about Villiers; this link should, I hope, get you into the Oxford Dictionary of National Biography's article on him for the next few days [though April 27th]. If it no longer works, well, this would be a good time for you to do some scouting about on your own! If you know of some reliable open access information about him, please leave it in the comments. Or go edit the Wikipedia page, which could use improvement!)
I should say something about what book this is, I suppose. It's John Smith's 1624 The generall historie of Virginia, New-England, and the Summer Isles. It's a very interesting book, and there's some great marginalia in it, but that will have to wait until another post, especially since my student is still in the middle of her research! But the arms thing is tricky to decipher and the Folger catalog record identifies only one of the two crests (James's, of course), so I wanted to lend her a hand in getting it sorted out. And I certainly didn't want to lead her astray with my desire for it to be Buckingham! So please leave me a note telling me what you think and I'll pass it on to her.