Best encyclopedia ever, one of the longest running encyclopes(short form for encyclopedias)ever, started in 1768 and runs today online, personally, the Britannica is just as useful online despite having to pay to see most parts, the last edition (15th, 2010) has a whopping over 36,000 pages! Personally, I'm glad they switched to being online because of reasons, If you are planning to sell these at a book sale, please do not do that, why? well, yes we live in 2020 (at the time of writing, hello time travelers!) and the World Wide Web is active, but keep it for old times sake. To sum it up, Encyclopedia Britannica is a godlike encyclopedia and useful for the young and old, no matter how old.