Maquinna's trust was particularly significant, as he was one of the most powerful chiefs of the region and had been very wary of the Spanish when Malaspina arrived. His friendship strengthened the Spanish claim to Nootka Sound, which was in question after the Nootka Crisis and resolved in the subsequent Nootka Conventions. The Spanish government was eager for the Nootka to formally agree that the land upon which the Spanish outpost stood had been ceded freely and legally. This desire had to do with Spain's negotiations with Britain than over Nootka Sound and the Pacific Northwest. Malaspina was able to acquire exactly what the government wanted. After weeks of negotiations the principal Nootka chief, Maquinna, agreed that the Spanish would always remain owners of the land they then occupied, and that they had acquired it with all due properness. The outcome of the Nootka Convention depended in part on this pact. In addition to the expedition's work with the Nootkas, astronomical observations were made to fix the location of Nootka Sound and calibrate the expedition's chronometers. Nootka Sound was surveyed and mapped with an accuracy far greater than had previously been available. Unexplored channels were investigated. The maps were also linked to the baseline established by Captain Cook, allowing calibration between Spanish and British charts. Botanical studies were carried out, including an attempt to make a type of beer out of conifer needles that was hoped to have anti-scorbutic properties for combating scurvy. The expedition ships took on water and wood, and provided the Spanish outpost with many useful goods, including medicines, food, various tools and utensils, and a Réaumur scale thermometer. After departing Nootka Sound the two ships sailed south, stopping at the Spanish settlement and mission at Monterey, California, before returning to Mexico. In 1792, back in Mexico, Malaspina dispatched two schooners (or "goletas") to conduct more detailed explorations of the Strait of Juan de Fuca and the Strait of Georgia. These were Sutíl, commanded by Dionisio Alcalá Galiano, and Mexicana, under Cayetano Valdés y Flores. Both were officers of Malaspina's. The ships were to have been commanded by two pilots of San Blas, Mexico, but Malaspina arranged for his own officers to replace them. In 1792, Malaspina's expedition sailed from Mexico across the Pacific Ocean. They stopped briefly at Guam before arriving at the Philippines, where they spent several months, mostly at Manila. During this period Malaspina