Delos
2 of the 7 encyclopedias on this shelf carry an entry for Delos. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
de'los, a rocky island in the Grecian Archipelago, the smallest of the Cyclades. It is about two miles square. In the mythological account Delos was raised from the bottom of the ocean by Poseidon, and for some time was a floating island moving from place to place. Hera, the wife of Zeus, was jealous of Leto, one of Zeus' favorites. The wrathful Hera bound Earth by oath to allow Leto no resting-place. Leto, known to the Romans as Latona, wandered over the world until at last she found this floating island, which, as it was not stationary, was not included in Earth's promise. Here Leto gave birth to twin children, Apollo and Diana, and henceforth the island was sacred to Apollo. Zeus chained Delos to the bottom of the ocean that it might be a safe home for Leto. Historically, the Ionians were the first inhabitants of Delos. A yearly festival was held here in honor of Apollo. After the fall of Corinth Delos became an important commercial center. It had an excellent harbor and was in the direct route from southern Europe to Asia. It is said that 10,000 slaves changed hands in one day at this place. A beautiful temple, erected in honor of Apollo, stood on the island. It was built of Parian marble, and contained a famous statue of the god and an altar in the shape of a cube. Once, in time of pestilence, the people consulted an oracle and were told to "double the altar of Apollo." Several ancient mathematicians attempted to solve the problem of doubling this cube. Hence the doubling of a cube is still called the Delian problem. Delos was devastated during the Mithridatic War, and never regained its former prosperous condition. The old town of Delos is only a mass of ruins, but remains of the temple may still be seen. The island has no permanent inhabitants. A few shepherds and goatherds from neighboring islands may be found there with their flocks during the summer season. See Doubling The Cube
Collier's New Encyclopedia (1921)
CYNTHUS, or ORTYGIA (now called SAILLES, SAYLLI, DELO, or DELI), is the smallest of the Cyclades, at the N. of Naxos, and was famous throughout antiquity as having been the birthplace of Apollo and Diana. According to the legend it was a floating island, but was rendered immovable in order that Latona might give birth in security to these two divinities. It was conse- 1 crated to the worship of Apollo and peopled by Ionians; and, in Homer's time, was the central seat of their political and religious union. Like all ancient temples of celebrity, that of Apollo at Delos was one of the great emporia for trade; and, after the fall of Corinth, the Delians, by wisely declaring their port free, secured that vast commerce tween the East and West of which that noble city had been the channel. Its mercial importance was further insured by the peculiar sanctity which attached to the island. Even hostile fleets rode quietly at anchor in its sacred harbor. The altar in the temple of Apollo is said to have been a perfect cube, and the doubling of it was a noted mathematical problem with the ancients, which went under the name of the problema Deliacum. The decline of Delos dates from the Mithridatic War, when it was laid waste by one of the generals of Mithridates.