After studying both classics and mathematics at the University of Cambridge, Sir Thomas Little Heath (1861-1940) used his time away from his job as a civil servant to publish many works on the subject of ancient mathematics, both popular and academic. First published in 1926 as the second edition of a 1908 original, this book contains the third and final volume of his three-volume English translation of the thirteen books of Euclid's Elements, covering Books Ten to Thirteen. This detailed text will be of value to anyone with an interest in Greek geometry and the history of mathematics.