(i) Whatever geographical information was available in pre-existing scientific and political documents was taken out and utilized.
(ii) Local people were hired as messengers to bring in intelligence on routes, roads, rivers, bridges, hills, etc.
(iii) Jesuits and ex-Jesuits took modern measurements and obtained valuable primary data.
(iv) Whenever an opportunity presented itself, Company officials made surveys.
(v) Lastly, as soon as it became possible, an exhaustive systematic field survey was ordered.
The geographic and geodesic work done in India under European auspices during the 17th and 18th centuries got eclipsed by the spectacular 19th century developments (epitomized by the naming of the highest point on the earth after a surveyor-general), it was solid and extremely significant in its time.