Transcriber’s note:

Front matter, ‘By’ changed from small caps to letter case, “By James Croll, LL.D., F.R.S. With”

Page 2, comma inserted after ‘Mag.,’ “Phil. Mag., July 1878;”

Page 25, full stop inserted after ‘Lectures,’ “Manchester Science Lectures.”

Page 37, heading ‘Testimony...’ changed to small caps.

Page 41, ‘years’ inserted, “Mean 3,378 years”

Page 54, full stop inserted after ‘Mem.,’ “Mem. Geol. Survey of Lancashire”

Page 59, full stop inserted after ‘vol. i.,’ “Memoirs of Geol. Survey, vol. i.”

Page 113, ‘radicles’ changed to ‘radicals,’ “argument from compound radicals”