What am I?

Cover the clues so you can only see number one. How many clues do you need before you know the answer?

1. I am about 20 centimetres long and about 10 centimetres wide.

2. At my centre is a rectangular opening and a removable blade covers this opening.

3. My blade slides back and forth with the aid of two narrow strips of wood nailed lengthways at each side of the board.

4. I was used in the kitchen.

5. I was handy on the days stews were cooked. My approximate date is 1870-1890.

Answer in the next TreasureLink.