Endymion
3 of the 7 encyclopedias on this shelf carry an entry for Endymion. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
en-dim'i-on, in Greek legend, a beautiful young shepherd who fed his flocks on Mount Latmus. According to one of the many stories about him, he had asked Zeus for immortal youth. Zeus granted his prayer, but, with the gift, condemned him to perpetual sleep. So the beautiful youth slept forever upon the mountain. Selene, goddess of the moon, looked down one clear night and saw Endymion asleep. His beauty charmed her and she came nearer. Stepping As from a golden car Out of the low-hung moon, she kissed the beautiful sleeper, and then watched over him that no harm might befall him through the night. The story of Endymion has always appealed strongly to poet and artist. A statute of Parian marble called The Sleeping Endymion was found in Hadrian's villa at Trevoli, and is now in the National Swedish Museum. The most noted poem on the subject is that of Keats, but it is noted because Keats wrote it, and not because he has succeeded in telling the story successfully. The first line is all anybody remembers and is as far as most people read. That line is the oft-quoted, "A thing of beauty is a joy forever." See Diana
Collier's New Encyclopedia (1921)
a shepherd, son of Æthlios and Calyce. It is stated that he asked Jupiter to grant him to be always young, and to sleep as much as he would; whence came the proverb, "to sleep the sleep of Endymion." Diana, or the moon, saw him unclothed as he slept on Mount Latmos, and became enamored of his great beauty, coming down from heaven every night to visit him.
1000 Classical Characters (1900)
A shepherd, son of Athlius and Calyce. He is said to have required of Jupiter that he might be always young. Diana saw him as he slept on Mount Latmos, and was so struck with his beauty that she came down from heaven every night to visit him.