ABSTRACT
Inhabited since Paleolithic times, the beginning of Vietnamese civilization dates back to the late Neolithic or early Bronze Age. Vietnam is tropical in the south and subject to monsoons in the north. The country is low, comprised of the Mekong Delta in the south, the Red River Delta in the north, central highlands, hilly, mountainous in the far north and northwest. France occupied all of Vietnam by 1884 and remained for the most part until 1954. The longitude of Hong Kong had been determined in 1881 by telegraph, so it was deduced that the longitude of Haiphong was now determined to better precision than was determined by the use of chronometers. In 1960, the triangulation of Cambodia and Vietnam was adjusted holding fixed two Cambodian stations connected to the Thailand adjustment of stations from the Cambodian-Vietnam adjustment.
