This crossnumber uses Roman numbers only and, every clue is the same.
(Examples of five Roman numbers are VIII = 8, LXXVI = 76, CXXXVI = 136,
CM = 900 and MDCCCLXII = 1862.)

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ACROSS DOWN
1. A perfect square 1. A perfect square
7. A perfect square 2. A perfect square
8. A perfect square 3. A perfect square
9. A perfect square 4. A perfect square
10. A perfect square 5. A perfect square
13. A perfect square 6. A perfect square
14. A perfect square 7. A perfect square
17. A perfect square 11. A perfect square
19. A perfect square 12. A perfect square
20. A perfect square 15. A perfect square
16. A perfect square
18. A perfect square
19. A perfect square
The 2digit squares can begin only with I or C, and no 8letter square can have an I in either the second or the third position, so 2down and 3down each begin with C.
That 8letter square, 1across, must then be MCCCLXIX.
The only 4letter square beginning with X is XLIX, so that must go in 6down.
The only 5letter square beginning with X is XXXVI, so that's 5down.
No 6letter square has an I in the second position, so the 2letter 8across must begin with C. Then 1down must be a 6letter square beginning with M and having D or M in the third position. Only MMMXXV fits this.
17across has three letters, the middle of which is V. Only XVI fits this.
14across is either IV or IX. Since no 4letter square begins with V, it must be IX, and 15down must be XLIX, the only 4letter square beginning with X.
When C is in the second position of a 6letter square, then so is the third position, so 10across begins with a C, and is either CXLIV or CXCVI. But if it were the latter, 11down would begin with C, which could only be CXXI, conflicting with the already placed I at the end of 17across. So 10across is CXLIV, and 11down is forced to be LXIV.
4down is CC_VI, which can only be CCLVI.
Then 9across, L_X_I, can only be LXXXI.
20across has 7 letters, the second of which must be V, X, D or M, as the second spot for a 2letter square at 19down, and whose 5th position already has an X. So 20across is MMCMXVI.
19down must be CM and 18down MDC.
The 4letter square at 16down, ending in I, must be CXXI.
The puzzle is then finished.
M C C C L X I X
M M M D C X L
C M L X X X I
C X L I V V X
X X X V I I X C
X V I M L X
V V C D I X
M M C M X V I

Posted by Charlie
on 20130527 14:13:27 