Charles P. Tompkins, surveyor and civil engineer, was an authorised engineer of irrigation and water supply in the State of Victoria, Australia, and was admitted as a land surveyor in that country in 1899. In 1901, in Maffra, Victoria, he married Margaret E. Ferguson, with whom he had two sons and a daughter. She died in 1937.
Tompkins was associated with the Johannesburg firm of H. Eckstein and Company from about 1904 to at least 1908. In 1905 he passed the Survey Certificate Examination of the University of the Cape of Good Hope and in due course was admitted as a government land surveyor in the Transvaal Colony. In 1906 he published a paper on "Chaining" in the Journal of the Institute of Land Surveyors of the Transvaal (Vol. 1(8), pp. 209-225), dealing among others with temperature effects and the choice of type of chain and procedure. He became a member of the Institute only in March 1907, served on its council for 1908/9, and as honorary secretary for 1909/10. He practised photography and shooting as hobbies.