 Copying the work methods of Cook's scientists, the scientists on this voyage would base their calculations of longitude on precision chronometers and the distance between the moon and the sun followed by theodolite triangulations or bearings taken from the ship, the same as those taken by Cook to produce his maps of the Pacific islands.As regards geography, Lapérouse decisively showed the rigour and safety of the methods proven by Cook.From his voyage, the resolution of the problem of longitude was evident and mapping attained a scientific precision.