Seeking Advice on City Map

[RedStorm]

I'm starting a new project, and it's an 1870's era fantasy/magic/steam city for a Pathfinder campaign. This is the first time I'm doing a major metropolis size map that's not a traditional fantasy city. It would be a large, urban, port setting along the shore near rivers and mountains that's on the early side of industrial revolution, with a 5-6 story brick buildings, gas-lit avenues, railway, outer areas etc. and a population of about 1.5 million. Think late 18th century Paris, New York, London - Victorian.

What I'm having difficulty with is - determining the actual size of the city. How many square miles does it need to cover to support the population? What elements does it need to have for that time period/population? What should the scale/size of the map be?

Any thoughts or advice are appreciated. Thanks.

[Azélor]

It is probably higher than what you think.

Industrial and most medieval cities were more crowded than they are today.
A good reference for the middle ages : http://www222.pair.com/sjohn/blueroom/demog.htm
Suggest that a n average city could have around 39 000 people per square mile and likely higher in a poor area.

An article about New York : http://www.nytimes.com/interactive/2...sent.html?_r=0

The numbers are really high. If I and the NYT get my calculation right, the lower East side had 388 888 people per square mile.

[RedStorm]

Interesting, so for a population of 1.2 million, an early industrial revolution city would be between 4 to 4.5 square miles. That kind of makes sense. I think Manhattan Island's lower-end covered about that much surface area at the end of the 18th century, but settled areas also went into Brooklyn etc. At around 500' per inch, I might get away with a map that's 36" across and still detailed enough to capture all the streets etc.

[Azélor]

It would cover a larger area than that because, if I understand correctly, that area was very poor. Other area in the city should be less crowded.