Robert Louis Stevenson was the most famous of the Stevensons, but not by any means the most productive. The Lighthouse Stevensons built every lighthouse round Scotland, were responsible for a slew of inventions in both construction and optics, and achieved feats of engineering in conditions that would be forbidding even today. The same driven energy which Robert Louis Stevenson puts into writing, his ancestors put into lighting the darkness of the seas. This text tells their tale.