 In 1851, the German-born Paul Julius Reuter opened an office in the City of London which transmitted stock market quotations between London and Paris via the new Calais to Dover cable.Reuter had previously used pigeons to fly stock prices between Aachen and Brussels, a service that operated for a year until a gap in the telegraph link was closed.Details of the employment of pigeons during the siege of Paris in 1870–71 led to a revival in the training of pigeons for military purposes.