Calcutta is a modern city compared with the rest of India. It has been built around old Fort William, which was the headquarters of the East India Company 200 years ago, and is situated upon the bank of the River Hoogly, one of the many mouths of the Ganges, about ninety miles from the Bay of Bengal. The current is so swift and the channel changes so frequently that the river cannot be navigated at night, nor without a pilot. The native pilots are remarkably skillful navigators, and seem to know by instinct how the shoals shift.