Naturales quaestiones (Natural Questions) is a Latin work of natural philosophy written by Seneca around 65 AD. It is not a systematic encyclopedia like the Naturalis Historia of Pliny the Elder, though with Pliny's work it represents one of the few Roman works dedicated to investigating the natural world. Seneca's investigation takes place mainly through the consideration of the views of other thinkers, both Greek and Roman, though it is not without original thought. One of the most unusual features of the work is Seneca's articulation of the natural philosophy with moralising episodes that seem to have little to do with the investigation. Much of the recent scholarship on the Naturales Quaestiones has been dedicated to explaining this feature of the work. It is often suggested that the purpose of this combination of ethics and philosophical 'physics' is to demonstrate the close connection between these two parts of philosophy, in line with the thought of Stoicism. The earliest date (terminus post quem) for writing is AD 60, and it is generally thought to have been written around 62 to 64 AD. The Naturales Quaestiones is addressed to Lucilius Junior: I am not unaware, Lucilius, excellent man, of how great is the enterprise whose foundations I am laying in my old age, now that I have decided to traverse the world, to seek out its causes and secrets, and to present them for others to learn about. [Book 3] The work originally had eight books, but the book on the Nile (book 4a) is missing the second part, whereas the book concerning Hail and Snow (book 4b) is missing the first half. These two books have been joined by tradition to become book 4. The contents of these seven books are as follows: meteors, halos, rainbows, mock suns, etc. thunder and lightning. (theory of thunderstorms ) water; this book also contains the description of the Roman heat exchangers, which were called "dracones", or "miliaria"; and a description of the deluge. the Nile (4a); hail, snow, and ice (4b). (theory of hail ) winds.