| Answer | Crossword Clue |
|---|---|
| photophone | an apparatus for the production of sound by the action of rays of light |
| Answer | Crossword Clue |
|---|---|
| photophone | an apparatus for the production of sound by the action of rays of light |
Crossword
a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.