Gillis, J.M Lieut

In 1849 the Californian gold rush started and the US Navy mounted a 4 year long, ambitious expedition to the southern hemisphere. The expedition had been requested by the US Congress and had a wide ranging scientific objectives. For example, measuring how gravity varied with distance from the earth's centre by taking instruments to the high altitudes in the mountainous Andes. During their leisure hours, the expedition was encouraged to observe interesting plants and animals. The artists involved drew these and on their return hand colored lithographs were made to document their discoveries.