George H. Thurston, eldest son of George Thurston, was a member of the American Society of Mechanical Engineers and worked for Fraser and Chalmers in Chicago, United States, before he came to the Witwatersrand in 1893. Initially he worked for Hennen Jennings* at the City and Suburban Gold Mining Company. From 1899 he was associated with Consolidated Gold Fields of South Africa, Johannesburg, and was chief engineer of Simmer & Jack Gold Mining Company. During the Anglo-Boer War (1899-1902) he served in the Railway Pioneer Regiment on the staff of the director of railways and was in charge of workshops for the reconstruction of bridges. He was captured by General de Wet's forces, but escaped twelve days later and was awarded a medal with four clasps.
Thurston was elected as the first vice-president of the Mechanical Engineers' Association of the Witwatersrand at its foundation in May 1898. He delivered a paper on "Steam traps" at one of the early meetings. At the first annual meeting, in 1899, he was elected president of the association. As a result of the Anglo-Boer War he remained in office until the society was re-activated in June 1902, when he delivered his valedictory address at the second annual meeting. The association changed its name to the Transvaal Institute of Mechanical Engineers in 1905 and he was still a member in 1909.
In 1903 Thurston became a member of the Chemical, Metallurgical and Mining Society of South Africa and at about the same time a member of the South African Association for the Advancement of Science. At the second annual congress of the latter, held in Johannesburg in 1904, he delivered a paper on "Fire protection on the mines". The paper was published in the association's Report for that year (pp. 411-420). In 1905 his position was that of assistant mechanical engineer to Consolidated Gold Fields of South Africa.