Clifton notes that, with the addition of Miles Berry, the partnership of Newton, Son & Berry took over from J. & W. Newton in 1830, and continued until 1838, when it was succeeded by Newton & Berry (1838-1841). However, some Newton, Son & Berry pocket globes (which presumably date from the later years of the partnership), do show sections of the Antarctic coastline, so the date of 1831 would seem to be correct, despite the absence of the word "Son" from the globe's title.