The Seventh Book

From Apollonius to Attalus. Peace be on you. I have sent to you with this letter of mine the seventh book of the treatise on Conics. In this book are many wonderful and beautiful things on the topic of diameters and the figures constructed on them, set out in detail. All of this is of great use in many types of problems,1 and there is much need for it in the kind of problems which occur in conic sections which we mentioned,2 among those which will be discussed and proven in the eighth book of this treatise (which is the last book in its. I shall strive to send that to you speedily. Farewell.