1. Subsequently, he started afresh with a systematic plan to survey and document the birds of the Indian Subcontinent and in the process he accumulated the largest collection of Asiatic birds in the world, which he housed in a museum and library at his home in Rothney Castle on Jakko Hill, Simla.

En ce faisant, il construit la plus grande collection d'oiseaux asiatiques du monde, installée dans un musée et bibliothèque chez lui au château de Rothney, sur la colline Jakko de Simla.