Egyptian fraction have been called "Horus-Eye fractions" after a theory (now discredited) that they were based on the parts of the Eye of Horus symbol. They were used in the Middle Kingdom in conjunction with the later notation for Egyptian fractions to subdivide a hekat, the primary ancient Egyptian volume measure for grain, bread, and other small quantities of volume, as described in the Akhmim Wooden Tablet. If any remainder was left after expressing a quantity in Eye of Horus fractions of a hekat, the remainder was written using the usual Egyptian fraction notation as multiples of a "ro", a unit equal
The Horus Heresy (novels) series became a sales success in its category. "Horus Rising" by Dan Abnett, the opening title, set the pace shortly after its release, topping "Locus" magazine's "Locus Bestsellers: Gaming-Related" list of August 2006; practically every title in the series had achieved the same or similar performance on this chart. "Horus Rising"s January 2011 CD audiobook release also appeared in ranked sales lists: the (abridged) edition was number 15 in a related chart published by "The Bookseller", covering 2011 UK sales up to September. "Legion" by Abnett, and "Battle for the Abyss" by Ben Counter, were listed in Nielsen BookScan's list