Pliny the Elder is the subject of In Our Time (this week). Pliny the Elder is the author of Natural History: A Selection (Penguin Classics). The programme information says that:
The Natural History contains information on zoology, astronomy, geography, minerals and mining and - unusually for a work of this period - a detailed treatise on the history of classical art. It's a fascinating snapshot of the state of human knowledge almost two millennia ago.
Pliny's 37-volume magnum opus is one of the most extensive works of classical scholarship to survive in its entirety, and was being consulted by scholars as late as the Renaissance. It had a significant influence on intellectual history, and has provided the template for every subsequent encyclopaedia.