Ships disappeared at sea all the time. There was no such thing as GPS, It would be another half century before wireless radio was invented. Passing vessels hailed one another and exchanged names with their captains, who would report who they had encountered, where and when, at the next port they arrived at. It was at the very best, a three month voyage from Britain to Australia. To send a letter and receive a reply would take half a year—If you were lucky. Mary Chapman waited. A whole year passed. Then the letter arrived.