Charles Edward Adams was born at Lawrence, Otago, New Zealand, on 1 October 1870, the son of Charles William Adams and his wife, Eleanor (Ellen) Sarah Gillon. His father had arrived in New Zealand from Tasmania in 1862 and was a geodesical surveyor in the provincial Survey Department. He was also an accomplished astronomer. The younger Adams was educated at Wellington College, Christchurch Boys' High School and Otago Boys' High School. In 1889 he entered Canterbury College where he studied science and civil engineering. He was awarded a Senior Scholarship in 1891 and graduated BSc with honours in 1892. From then until 1896 he lectured in applied mathematics at the Lincoln School of Agriculture.
On 18 November 1896 Adams married Eleanor Robina Jacobson at Akaroa; they were to have three sons and three daughters. Adams went to Napier in 1897 and worked as a surveyor until 1899. He then joined the Lands and Survey Department in Wellington and in the early 1900s lectured part time in geology at Victoria College. In 1902 he was appointed secretary of the Surveyors' Board and by 1905 was listed as a licensed surveyor.
Adams was awarded an MSc from the University of New Zealand in 1909 and by 1910 was chief computer at the head office of the Lands and Survey Department. The techniques he devised during this period for the prediction of tides were, with few modifications, employed in New Zealand until 1924. In 1911, while continuing to discharge his duties in the department, he was appointed astronomical observer at Wellington. Early the following year he became government astronomer. He spent 1915 as Martin Kellogg fellow at the Lick Observatory, California, then returned to a full-time position as government astronomer in the Internal Affairs Department. He was awarded a DSc from the University of New Zealand in 1915 for a thesis entitled 'Harmonic analysis of tidal observations and predictions of tides'.
It was Adams's work in astronomy that identifies him as one of New Zealand's important scientists. He developed methods of computation of planetary ephemerides and cometary orbits and made observations of sunspots, variable stars, planets and auroras. In 1922 he accompanied the Lick Observatory solar eclipse expedition to Western Australia and in 1930 led an eclipse expedition to Niuafo'ou, in the Tongan group. He pioneered the use of cinematography for astronomical timing. The camera he devised for photographing the Moon against its background stars, so that accurate longitudes and lunar positions could be gauged, forms the basis of the standard modern instrument.
As government astronomer Adams was in charge of the Hector Observatory and responsible for maintaining accurate time for scientific and civil purposes such as navigation. Time signals were originally disseminated in the main ports by the dropping of a ball from a masthead when telegraph signals were received from the observatory in Wellington. At Adams's suggestion the timeball in Wellington was replaced in 1911 by coloured lights on a mast at the observatory. In 1916 he initiated transmission of time signals by radio. Although the accuracy claimed for outgoing signals was a quarter of a second, errors of a second or more were not unknown at weekends and during the night.
Seismology was added to Adams's responsibilities in 1920. The Hector Observatory was renamed the Dominion Observatory in 1925, and from 1927 Adams signed his annual reports as dominion astronomer and seismologist. This marked the beginning of a decrease in government work in astronomy and an increased emphasis on seismology, a trend which accelerated with the formation of the Department of Scientific and Industrial Research in 1926. The period 1929 to 1934 was the most seismically active in New Zealand's recorded history. During these years Adams sought to maintain rigorous observatory procedures while documenting major earthquakes such as those at Arthur's Pass and Murchison in 1929, Hawke's Bay in 1931, Wairoa in 1932 and Pahiatua in 1934. A series of papers he wrote on seismology in New Zealand describe the development of the young science under his guidance. He was also the senior author of an important study of the Hawke's Bay earthquake.
It was characteristic of Adams that, prior to his retirement in April 1936, he personally trained his protégé and successor, R. C. Hayes, claiming that the training he could give was superior to anything available at a university. He was the founder and president of the New Zealand Astronomical Society (now the Royal Astronomical Society of New Zealand), an associate in astronomy at Yale University and a fellow of the Royal Astronomical Society, London. He was also very active in the establishment of the Carter Observatory, believing that the capital city was entitled to an up-to-date observatory and telescope.
Adams pursued a number of interests outside his work. A Freemason, he was also president of the Wellington Philosophical Society and of the Wellington Shakespeare Society, an honorary fellow of the New Zealand Institute of Architects, and an associate of the Institute of Actuaries, London. His musical interests included the Gilbert and Sullivan light operas and playing the piano.
Charles Adams died in Wellington on 31 October 1945. Eleanor Adams had died in 1941. In 1991, 46 years after Adams's death, an asteroid discovered in 1985 by astronomers at the Mt John University Observatory, Lake Tekapo, was named Ceadams in his honour by the International Astronomical Union.