1844 Alan Stevenson, son of Robert completes the Skerryvore lighthouse twenty-five miles off the coast of Mull. It is considered a feat of engineering genius with a tower 48 metres high.

Robert's son, Alan, also became a famous engineer by designing a lighthouse, which is probably one of the wonders of Victorian engineering. On the west coast he constructed a light tower on a reef that was 48 metres high. He calculated that if the weight of the stone was enough, there was no requirement for dovetailing the stones. The lighthouse was constructed of over 4000 tons of stone and relied on weight alone to keep it in position. Needless to say the light is still there guiding mariners away from the reef.