This crossword No. 9142 clues and answers were published on Fri 20 Aug 1999 and the puzzle can be visited by following The Guardian Quick Crossword No. 9142 link.
All Across Clues and Answers:
5-across – Made an error : WENTWRONG
8-across – Military cap with circular top : KEPI
9-across – Pillar supporting staircase rail : BALUSTER
10-across – Figurine : STATUE
11-across – Pure – virtuous : CHASTE
13-across – Hidden – thicket : COVERT
15-across – Conquer : SUBDUE
16-across – Pose : ATTITUDE
18-across – Boulder : ROCK
19-across – Continued – took the lead : WENTAHEAD
All Down Clues and Answers:
1-down – Disparage : BELITTLE
2-down – Firm : STABLE
3-down – Merrymaking : FROLIC
4-down – Responsibility : ONUS
6-down – Left home, often to do battle : WENTFORTH
7-down – Shared expenses : WENTDUTCH
12-down – Tree-dwelling : ARBOREAL
14-down – Reliable : TRUSTY
15-down – Boil : SEETHE
17-down – Wild goat with large horns : IBEX
This crossword has in total 20 where 10 are across and 10 are down.