The culprit is a molecule called gliadin, which is found in certain gluten-containing grains and causes symptoms in gluten-sensitive people. The grains that cause the greatest problems are wheat, rye, barley, spelt, and kamut; whereas corn, rice, millet, and buckwheat are generally considered safe.
The Forth Bridge's piers are constructed from 120,000 cubic yards of concrete and masonry, faced with 2 ft thick granite. 200 trains use the bridge every day, carrying 3 million passengers each year. The total painted area of the Forth Bridge is 230,000 sq metres, requiring 240,000 litres of paint.
These acted as guides for building the pier, which was to hold the bridge, being built by the Starr Manufacturing Company of Dartmouth. The wooden trestle-work of the bridge, constructed by M.J. Hogan of Quebec, rested on eight foot stone-filled cribs, spaced on the harbour bottom every 10 feet (3.0 m).