Crossword No 1 (fourth series)

                       
             
10                11           
           
12      13      14               
         
15  16      17          18       
         
19                20        21   
           
22            23        24       
             
25                26           
             

Each across clue contains a superfluous word.  The initial letters of these 15 words, taken in order, spell out the answer to 4 down.

Clues across
8Potentially a big maths problem, taking one’s breath away (6)
9He designs extra power unit with little hesitation (8)
10Shredded rare Dutch Edam – it’s sweet! (8)
11A new yo-yo (half missing) needs changing.  It’ll go down, but not up again! (3-3)
12Stop a queen concealing nephrite lacking transparency (6)
14Cause explosion – note December date is changed (8)
15Part of the world held by a belligerent Siamese (4)
17Cyril Rutherford arranged this song (5)
18Enemies race around area (4)
19Delicious food always makes Maria sob (8)
20Residue from fire and mineral kept on dry land (6)
22Dog caught Stan’s faithful partner (6)
23Fat Alice’s photo is thrown out into pedestrian route (8)
25See sea swirl around radio (8)
26Rushed back to ply oars in Tasmanian strait (6)
Clues down
1Unconscious snake seen round shelter (6)
2Wrinkled hose used for footwear (4)
3Place surrounding a royal residence (6)
4See preamble (three words)
5Unbeliever’s acting so badly (8)
6Below Welsh town? Yes, below! (10)
7Centred a wonky drink container (8)
13Arrow was in first place – fell out (10)
16Typifying slimy cob, perhaps (8)
17Eavesdropper spreading untruth about gun, right? (8)
20Somewhere near a circle (6)
21Leading seaman turns up for food allowance (6)
24Ponder opening of sweat gland (4)

To see the solution, click here