Good morning early birds,
4 Across, Barracks Spooner's eccentric experts (4,5)
12 Across, Encourages most of the planet to have birds around (8)
15 Across, Exchange around 100 men for invention of 23 (10)
[ 23 = figure of speech capturing the essential folly of writer (8) ]
19 Across, In conditions of poor visibility cross warrior can indulge in hobby of dubious legality (3,7)
Compiler - ALCHEMI
Many Thanks