GUEST: It was my friend's, and she used to keep it in her closet. And I just admired it, kept after her to get it from her. And what she has told me, it was her grandparents', and they were in Germany. And in the '30s they went to London. And when she was a little girl it was in the nursery at her home and she used to remember seeing red Roman numerals light up.

APPRAISER: And eventually you acquired it.

GUEST: I did.

APPRAISER: Well, this is very appropriately called a night clock. And it was meant to illuminate the dial at night. So on this wonderfully painted dial with this nativity scene and the star of Bethlehem up on top, you'll also notice a skeletonized disc which rotates behind there, telling the time with Roman numerals. And as you know, when we open the door, we see a space inside where you would place a candle. And that candle would show through on the other side. Now, it's the candle part of this clock that makes this an extremely rare clock because when you're lighting a candle and forgetting about it, you're apt to burn your house down and burn the clock down, too. The chimney at the top would let the heat out and let the smoke out from the candle, and no doubt provided a little smoke into the room and soot on your ceiling. But some very sensible clockmaker put an electric fixture in this so that an electric light would shine rather than a candle inside, and thus avoiding any hazards of fire. And it was in no way destructive to the case. They mounted it in there very carefully. It does have the original clock movement with its original verge and crown escapement. And this clock, which was made by Christoph Munhofin in Prague, probably dates to 1675, 1700.

GUEST: Wow.

APPRAISER: And that's a very early age for a clock, so this has seen some restoration through the years, but an extremely rare clock and a very important clock. I would appraise this for auction purposes today at $8,000 to $12,000.

GUEST: Wow. Wow.

APPRAISER: So that was a nice gift.

GUEST: Oh, my gosh. I'm shocked. Wow. I'm going to move it to the living room. It's been in my hallway. (laughter)

APPRAISER: I'm so glad you brought it in to Antiques Roadshow.

GUEST: Oh, so am I. (laughing)