louis dufresne was one of the naturalists on board the "astrolabe", which accompanied by the "boussole", left brest in august 1785 on a voyage of discovery. the ships went first to madeira and tenerife, then to trinidad and then to the coast of brazil including santa catarina island). rounding cape horn the expedition landed at concepción and on to the sandwich islands and then sailed north along the coast of north-west america to alaska. in 1786, the expedition resumed this time visiting monterey before crossing the pacific to land in macao in china. in 1787 the boats returned to france.