In spite of their apparent insignificance and of their total failure, these attempts to reopen communication with the outer world, notwithstanding the closing of the Scheldt, are symptomatic of a remarkable economic revival. The population had risen from two to three millions, during the first half of the eighteenth century, and Brussels, with 70,000 inhabitants, Ghent and Antwerp, with 50,000 each, had regained a certain part of their former prosperity. Native industry, strongly encouraged by protective measures, made a wonderful recovery. In the small towns and the country-side, the linen industry benefited largely from the invention of the fly shuttle, over two hundred thousand weavers and spinners being employed in 1765. Lace-making had made further progress, specially in Brussels, where fifteen thousand women followed this trade. In 1750 Tournai became an important centre for the china industry, its wares acquiring great renown. The extraction of coal in the deeper seams had been facilitated by the use of recently invented steam-pumps, and the woollen industry around Verviers was producing, in 1757, 70,000 pieces of material a year. Such progress largely compensated for the decadence of tapestry, which had been ruined by the rivalry of printed stuffs. The Government intervened also actively in agricultural matters by encouraging small ownership, at the expense of great estates, and the breaking up of new ground. The land tax was more evenly distributed and the great work of draining the Moeres (flooded land between Furnes and Dunkirk), which had been begun by the archdukes, was successfully completed (1780). The peasants also benefited from the cultivation of potatoes, which were becoming more and more popular. The only severe check to economic activity was caused by the War of the Austrian Succession, which opened at the accession of Maria Theresa (1740), and which opposed the forces of Austria, England and Holland against the coalition of Prussia, France, Spain and Poland. A British landing in Ostend prevented an early invasion of the Southern Netherlands by France during the first year of the struggle, but in 1744 French troops appeared in West Flanders, and Belgium became once more the "Cockpit of Europe."