"Petrarch made a collection of the letters he wrote. Divided into 24 books, there are a total of 350 letters. Due to copyrights of the English translations they can not all be shown here. However, some translations are available and they are included below. A complete list of letters from this collection as titled by Aldo S. Bernardo is also available."
(Source: website Francesco Petrarch & Laura deNoves)
Citation on the website:
"If anything gratifies you in these letters of mine, I freely concede that it is not really mine but yours; that is to say, the credit is due not to my ability but to your good-will. You will find no great eloquence or vigour of expression in them. Indeed I do not possess these powers, and if I did, in ever so high a degree, there would be no place for them in this kind of composition. Even Cicero, who was renowned for these abilities, does not manifest them in his letters, nor even in his treatises, where, as he himself says, the language is characterised by a certain evenness and moderation."