Pendulum the pendulum could be used to measure the force of gravity. During his expedition to Cayenne, French Guiana in 1671, Jean Richer found that a pendulum clock was minutes per day slower at Cayenne than at Paris. From this he deduced that the force of gravity was lower at Cayenne. In 1687, Isaac Newton in "Principia Mathematica" showed that this was because the Earth was not a true sphere but slightly oblate (flattened at the poles) from the effect of centrifugal force due to its rotation, causing gravity to increase with latitude. Portable pendulums began to be taken on voyages
1851 in Australia city in the Dandenong Ranges, Belgrave was first settled, making it the oldest town in the Dandenong Ranges. Governors of the Australian colonies: 1851 in Australia 1851 in Australia was a watershed year. It saw the start of the Australian gold rushes with significant gold discoveries in both New South Wales (near Bathurst) in February and Victoria in July. As a result of the Gold Rushes, the European population of Victoria increased from 97,489 in 1851 to 538,628 in 1861 and the population of NSW increased from 197,265 in 1851 to 350,860 in 1861. Victoria became a self-governing colony. Sentiment