Each of nine clues contains a misprinted letter in the definition part. Corrections of misprints spell a two-word phrase. Clues in italics are cryptic indications of partial answers; in each case, the indicated part must be placed as suggested by the thematic phrase to create the full answer to be entered in the grid. Resulting entries (one of which is a two-word name) are defined by unclued lights.
 

Across

1   Observation point secured by dog in window (5, hyphened)
4   Chatter about old vestment, very dark (9, hyphened)
9   Ice can help with treatment of the head (10)
14  Master destroys foxes (5)
15  Caught by magnetic field strength
16  State mineral grade (6)
22  Confide foolishly in duo ensnaring politician (7)
24  Melancholy song following trouble (4)
25  Trespass, dropping in
27  Amateur managed entire course (7)
33  Primate accepted spirit after singular uncertainty (6)
34  Both tense and ready (5)
35  Add force in a dilemma (5)
37  Rail and twisted rope (7)
38  Basket for fish in boat (5)
39  Lecturer with unfinished commission retiring
40  On spot, holding fort, reflected calmly (9)
41  What saint experienced? On the contrary (5)
 

Down

1   Mostly wandering land, I’m not entering quarry (13)
2   Continually losing energy
3   Free silver grabbed by stupid person ignoring diamonds (6)
4   Bony kind, left out (6)
6   Song, so very loud, ceases (7, two words)
7   Wife after course wanting electronic operating system (5)
8   Money added to pool for material (8)
10  Way to rattle an unsettled legal agent (13, three words)
13  Tables and gadgets broken by silly ape (7)
15  Prepared to scan constellation (6)
17  Part of field in general full (6)
18  Exercises ending in appraisal and mature chat (6)
19  West African I see working around valley (7)
20  Suite designed to accommodate hot romp (6)
23  Knight in crazy search for poisonous plant (8)
26  Buffalo one hurt? Cross about that (7)
29  Basketwork in pyre is offered up (6)
30  Strike, not united, overturned
31  Music including medley, mostly drinking songs (6)
32  Wasted power separating sediment (5)
36  Fellow raised office idiom (4)
 
A first prize of £30 for the first correct solution opened on 6 March. There are two runners-up prizes of £20. (UK solvers can choose to receive the latest edition of the Chambers dictionary instead of cash — ring the word ‘dictionary’.) Entries to: Crossword 2297, The Spectator, 22 Old Queen Street, London SW1H 9HP. Please allow six weeks for prize delivery.