At the VOC base in Chapra the saltpetre purchased in neighbouring Patna was processed at the Company refinery. The saltpetre was destined for the European market, as it was an essential ingredient in the manufacture of gunpowder. As such the demand for saltpetre mushroomed during wartime. The Company's country estate and gardens at Chapra probably served for the cultivation of vegetables for VOC employees. The reservoir functioned not only as a supply of drinking water, but also provided for the irrigation of the gardens.