The second voyage of the "Beagle" was commanded by Fitz-Roy and lasted from 1831 to 1836. The mission given to Fitz-Roy was two-fold. Firstly, he was to continue the survey work of South America by King on the first voyage and extend it through Tierra del Fuego around to the coast of Chile on the west side of the continent. Secondly, he was to establish a chain of reference points with known longitudes that could be used by future mariners to accurately set their chronometers. This was also the voyage that carried Charles Darwin. Fitz-Roy was given a detailed list of objectives by the Admiralty Hydrographer's office. The first part of the journey more or less repeated King's, partly to check King's results, but also to break the journey into small sections so that the chronometers could be rated over four days at each stop and changes in temperature between references would not affect them too severely.