a labour shortage, so had to incorporate temporal workers in addition to the permanent staff. Another response by the latifundia to labour shortages was to act as merchants buying wheat produced by independent farmers or from farmers that hired land. In the period 1700 to 1850 this second option was overall more lucrative. The 1687 Peru earthquake also ended a Peruvian wine-boom as the earthquake destroyed wine cellars and mud containers used for wine storage. The gradual decline of Peruvian wine even caused Peru to import some wine from Chile as it happened in 1795 when Lima imported 5.000 troves (Spanish: botijas) from Concepción in southern Chile. This particular export showed the emergence of Chile relative to Peru as a wine-making region. Haciendas of central Chile are believed to had become labour-saturated by 1780 generating an "excess" population that could not be incorporated into their economy. Some of this population settled in the outskirts of larger cities while other migrated to the mining districts of Norte Chico. Chile saw an unprecedented revival of its mining activity in the 18th century with annual gold production rising from 400 to 1000 kg over the course of the century and the silver annual production rising from 1000 to 5000 kg in the same interval. In the 18th century the shipbuilding industry in Valdivia, one of the city's main economic activities, reached its peak building numerous ships including frigates. Other shipyards of Chile included those of Concepción and Chiloé Archipelago. The Chiloé shipyards constructed the bulk of the ships in Chile until the mid-18th century. In 1794 a new shipyards was established the mouth of Maule River (present day Constitución). Despite some navigators expressing that Valdivia had better conditions than Guayaquil in Ecuador, this last port was the chief shipyard of the Spanish Empire in the Pacific. Direct trade with Spain over the Straits of Magellan and Buenos Aires begun first in the 18th century constituting primarily an export route for gold, silver and copper from Chilean mining. By the same time Spain's trade monopoly with its colonies was successively weakened by smugglers from England, France and United States. Independence Era (1810–1830) The independence wars in Chile (1810–1818) and Peru (1809–1824) had a negative impact on the Chilean economy. Trade was disrupted and armies in Chile pillaged the countryside. The war made commerce a high risk activity and royalist Peru, then the only market