n = 12
x = -8.6602540378444E-5 y = 5.0E-5
gc = 51.502686111111, 3.6157972222222 gcx = 51.502686111111 gcy = 3.6157972222222
51.502599508571, 3.6158472222222
51° 30' 9", 3° 36' 57"
51.502671111111, 3.6157712414601