Solution to Sunday Independent Cryptic Crossword no 1,252

Across: 1 Strip light; 6 Halo; 9 Authorship; 10 Glut; 12 Drag; 13 Indraught; 15 Imposter; 16 Idiocy; 18 Can-can; 20 Tarragon; 23 Piecemeal; 24 Navy; 26 Idle; 27 Instructor; 28 Earn; 29 Knock-kneed. Down: 1 Slam; 2 Rat trap; 3 Ploughshares; 4 Inspires; 5 Hairdo; 7 Allegro; 8 Outstaying; 11 Mandarin duck; 14 Discipline; 17 Balletic; 19 Needler; 21 Gavotte; 22 Pennon; 25 Grid.