Between 1891 and 1896, the Lincoln architect Herbert Henry Dunn was his assistant [1] and at the same time, 1891–6, George Robinson Harding, was articled to him.

Thropp was a member of the Institute of Civil Engineers and was surveyor to the Lindsey County Council.

In 1883 Thropp published a 3rd edition of Padley's large scale survey of Lincoln.

[4] James Thropp of 27 Bailgate died 8 September 1923 [5] Apart from work for the Lindsey County Council, Thropp also laid out new streets in Lincoln and designed terraced houses and villas.

Antram N (revised), Pevsner N & Harris J, (1989), The Buildings of England: Lincolnshire, Yale University Press.