It was about seven o'clock in the evening when sobrecargo Austin boarded the little mail-boat Estremedura as she lay rolling at anchor on the long, moon-lit heave that worked into the roadstead of Santa Cruz, Palma. Sobrecargo means much the same thing as purser, and Austin was an Englishman, though the Estremedura was to all intents and purposes a Spanish steamer. She traded round the islands of the Canary archipelago with mules and camels, tomatoes,...