n = 12
x = -8.6602540378444E-5 y = 5.0E-5
gc = 51.502688888889, 3.6157861111111 gcx = 51.502688888889 gcy = 3.6157861111111
51.502602286349, 3.6158361111111
51° 30' 9", 3° 36' 57"
51.502673888889, 3.615760130349