In 1822 he became director of the Seeberg observatory, and in 1825 was promoted to a corresponding position at Berlin, where a new observatory, built under his superintendence, was inaugurated in 1835.
In the reign of Tiberius he held the office of praetor, and was appointed to the superintendence of the roads and bridges.
Under Arnold's superintendence the school became not merely a place where a certain amount of classical or general learning was to be obtained, but a sphere of intellectual, moral and religious discipline, where healthy characters were formed, and men were trained for the duties, and struggles and responsibilities of life.
The navy had its own censorship department at the Admiralty, under the superintendence of Sir Douglas Brownrigg.
Libraries and archives are under the superintendence of the Ministry of Public Instruction.