For more than fifty years after the formation of the Indian Railways in 1857, there was one crucial element that was missing on the nation's trains: toilets.
Passengers had to wait till till the stations to answer the call of nature, and it was not until a passenger named Okhil Chandra Sen wrote this angry yet amusing letter in 1909 that toilets were installed on Indian trains.
So if you're in India, and you have to go to the bathroom aboard one of their trains, you have Mr. Sen to thank:
Image: Richard Fellowes
From the notable Letters of Note