- Soo Line High Bridge (Wikipedia)
The Soo Line High Bridge, also known as the Arcola High Bridge, is a steel deck arch bridge over the St. Croix River between Stillwater, Minnesota and Somerset, Wisconsin, United States. It was designed by structural engineer C.A.P. Turner and built by the American Bridge Company from 1910 to 1911. The bridge was listed on the National Register of Historic Places in 1977 for its national significance in the themes of engineering and transportation. It was nominated for its exceptional dimensions, beauty, innovative engineering techniques, and importance to transportation between Minnesota and Wisconsin.
- Silicon dioxide (Wikipedia)
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula SiO2, commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant families of materials, existing as a compound of several minerals and as a synthetic product. Examples include fused quartz, fumed silica, opal, and aerogels. It is used in structural materials, microelectronics, and as components in the food and pharmaceutical industries. All forms are white or colorless, although impure samples can be colored.