Puerto del Pendulo, doubtful sound: the Malaspina expedition’s visit to New Zealand in quest of the true figure of the earth

Abstract

The Malaspina expedition was assigned the task of conducting a series of experiments using the pendulum to measure the strength of gravity at different locations during the course of its voyage. The immediate objective was to establish the length of a pendulum beating at seconds at latitude 45º as the basic unit of a new universal system of measures. Although the new unit, the metre, was eventually established on a different principle, the gravity experiments carried out by the expedition resulted in useful geodesic information and incidentally led to the first charting of Doubtful Sound in New Zealand.