Note 324 — Chapter XVII · Robert Stephenson’s Tubular Bridges at Menai and Conway.
Reading edition
The simple fact that in a heavy storm the force of impact of the waves is from one and a-half to two tons per square foot, must necessarily dictate the greatest possible caution in approaching so formidable an element. Mr. R. Stevenson (Edinburgh) registered a force of three tons per square foot at Skerryvore, during a gale in the Atlantic, when the waves were supposed to run twenty feet high.