GUEST: I got it about 20 years ago from a book dealer in Geneva, New York, which is right near here. And it also had the name of the person on a little slip of paper inside of it, and it said, "Professor Charles Avery, Hamilton College."

APPRAISER: That's the story here, that you've identified who the subject was. Most of the time when we see daguerreotypes, we don't have any idea of who they were. What did you find out about Charles Avery?

GUEST: Well, I started my research by contacting the librarian at Hamilton College. And he sent me biographical materials about Professor Avery, who, it turned out, was a chemistry professor at the college. And he was an early photographer himself, when photography was just beginning in this country.

APPRAISER: Right, right.

GUEST: And he ended up sleeping in his laboratory. As a result of sleeping in his laboratory, he inhaled the fumes, which were apparently toxic.

APPRAISER: Right, bromine. Very toxic chemical that was an important part of making daguerreotypes.

GUEST: Right, you would have thought he'd know better as a chemistry professor, but apparently he didn't. And he and his wife, as was the custom then, took a trip to recover. And they went to London, and at that time, there was a photographer taking photographs in London.

APPRAISER: And that photographer was, as we know from your research, Antoine Claudet.

GUEST: Yes.

APPRAISER: Now, Charles Avery not only was an early daguerreotypist, but he learned how to make daguerreotypes from Samuel Finley Morse, who was the guy who brought photography to America from France in 1839. And we know that his interests were stimulated by Morse, and in fact, from your research we found out that Morse actually came to Hamilton College to help him learn how to take photographs. This is a very nice, typically English sort of daguerreotype by one of the great masters. And by 1844, Antoine Claudet was already very well known as a celebrity photographer in London. I would tell...how much did you pay for this daguerreotype?

GUEST: I think it was ten, but it could have been up to 20. That was about all I'd pay for photographs at that time.

APPRAISER: About ten to 20 dollars, and you bought it about 20 years ago.

GUEST: Yes.

APPRAISER: It's a collectible daguerreotype about the history of photography. I would tell you today at auction I would estimate the value of this, it would probably be between $2,000 and $3,000, or $2,000 and $4,000.

GUEST: Wow.