What is the origin of the term manhole?

The term manhole originated between 1785 and 1795. A manhole is a hole, usually with a round cover, through which a person may enter a sewer, drain, steam boiler, etc, especially one located in a city street. The word is a combination of two words — ‘man’ and hole’. However in today’s era of gender neutrality, some would argue that any use of the word `man’ in manhole, is biased and should be avoided.