2013 Dingxi earthquakes
The magnitude of the initial earthquake was placed at Ms 6.6 by the China Earthquake Data Center with a focal depth of 20.0 kilometres (12 mi). It was measured at Mw 5.9 by the United States Geological Survey (USGS) and Mw? 6.0 by the European Alert System. Another strong quake occurred about one hour later, measuring 5.6 magnitude by the USGS. As of 18:00 CST (10:00 UTC), 22 July 2013, 422 aftershocks had been recorded. The earthquakes caused at least 95 deaths, and more than 2,300 people were injured.
Sandford Fleming died
Sir Sandford Fleming as a Scottish Canadian engineer and inventor. Born and raised in Scotland, he emigrated to colonial Canada at the age of 18. He promoted worldwide standard time zones, a prime meridian, and use of the 24-hour clock as key elements to communicating the accurate time, all of which influenced the creation of Coordinated Universal Time. He designed Canada's first postage stamp, produced a great deal of work in the fields of land surveying and map making, engineered much of the Intercolonial Railway and the first several hundred kilometers of the Canadian Pacific Railway, and was a founding member of the Royal Society of Canada and founder of the Canadian Institute (a science organization in Toronto).
First Tay Bridge construction started
First Tay Bridge Plans for a bridge over the Tay to replace the train ferry service emerged in 1854, but the first Tay Bridge did not open until 1878. It was a lightweight lattice design of relatively low cost with a single track. Upon its completion in early 1878 the Tay Bridge was the longest in the world. While visiting the city, Ulysses S. Grant commented that it was "a big bridge for a small city". On 28 December 1879, the bridge suddenly collapsed in high winds while a train was crossing, killing everybody on board. The incident is one of the worst bridge-related engineering disasters in history.
John A. Roebling died
John Augustus Roebling was a German-born American civil engineer. He designed and built wire rope suspension bridges, in particular the Brooklyn Bridge, which has been designated as a National Historic Landmark and a National Historic Civil Engineering Landmark.
Thomas Stevenson was born
Pioneering Scottish civil engineer, lighthouse designer and meteorologist Thomas Stevenson designed over thirty lighthouses in and around Scotland. He also invented Stevenson screen used in meteorology as part of a standard weather station.
Gaspard de Prony was born
Baron Gaspard Clair François Marie Riche de Prony was a French mathematician and engineer, who worked on hydraulics. n 1791, de Prony embarked on the task of producing logarithmic and trigonometric tables for the French Cadastre. The effort was sanctioned by the French National Assembly, which, after the French Revolution wanted to bring uniformity to the multiple measurements and standards used throughout the nation. In particular, his tables were intended for precise land surveys, as part of a greater cadastre effort. The tables were vast, calculating logarithms from 1 to 200,000, with values calculated to between fourteen and twenty-nine decimal places.
