[Drawing of a circle with a cross through it] [At 12 o'clock] 40 [under that] 0 [At 3 o'clock] 10 [At 6 o'clock] 20 [At 9 o'clock] 30
Center of circle is the location of guns 0 or 40 is location of target
[an arrow is drawn to the line near the 10] it is labelled WX (Rn) [an arrow is drawn to the line near the 20] it is labelled WZ (Def)
Guns R X = L-B guns L X = L + B
L = D tan X
______ G T (kil)
W = D sin X
___________ GT kil.