Cassander, Ptolemy, Lysimachus, and Seleucus all likewise called themselves kings.  And still the war went on.  Demetrius was sent against the island of Rhodes, which belonged to Ptolemy, and besieged the city a whole year, but could not take it, and was obliged to make peace with the islanders at last, and to give them all the machines he had used in the siege.  These they sold for 300 talents, and used the money to make an enormous brazen statue of Apollo, to stand with one foot on each side of the entrance of the harbour.  Ships in full sail could pass under it, and few men could grasp its thumb with their arms.  It was called the Colossus of Rhodes, and was counted as the seventh wonder of the world, the others being the Temple of Diana at Ephesus, the Tomb of Mausolus, the Lighthouse of Messina, the Walls of Babylon, the Labyrinth of Crete, and the Pyramids of Egypt.  They also consecrated a grove to Ptolemy for the assistance he had given to them.