The Pearl Divers and Crusoes of the Sargasso Sea by Gordon Stables

Captain Antonio, as we may now call him, was a very busy man indeed, and spent all his forenoon in his study making experiments, that seemed to Barclay Stuart to partake of the marvellous. These were generally electrical.

But he found time to teach Barclay both ashore and afloat, and Davie Drake -- shy, handsome Davie, who blushed like a red, red rose when any one spoke suddenly to him -- was taught when afloat in the sloop.