The Collaborative International Dictionary
Claude Lorraine glass
Claude Lorraine glass \Claude" Lor*raine" glass`\ [Its name is supposed to be derived from the similarity of the effects it gives to those of a picture by Claude Lorrain (often written Lorraine).] A slightly convex mirror, commonly of black glass, used as a toy for viewing the reflected landscape.
Wiktionary
claude lorraine glass
n. A slightly convex mirror, commonly of black glass, used as a toy for viewing the reflected landscape.
Usage examples of "claude lorraine glass".
It was placed at such a cunning angle against the darkness of the forest opening that it made a soft and mysterious mirror, not unlike a Claude Lorraine glass, wherein not only the passing figure of the young girl was seen, but the dazzling green and gold of the hillside, and the far-off silhouetted crests of the Coast Range.