Manhattan’s population density is changing – and not in the way you’d expect

Residents in a Bayard Street tenement around 1890. Image: Jacob Riis at Wikimedia Commons.

Below are two population density maps of Manhattan. One is from 1910; the other 2010. The latter shows a city that’s absorbed the explosion in high-rise living and the growing desperation of pretty much everyone in the world to live on an island that isn’t getting any bigger (well, not much bigger, anyway). 

The twist is, the diagram that best mirrors the skyscraper-littered shape of modern Manhattan actually shows the city at the beginning of the last century. Here are the same diagrams again:

Image: Schlomo Angel, Planet of Cities.

Over the past century, Manhattan’s population has actually fallen by a little under 25 per cent. To put it even more plainly:

This shrinkage tells a story of improved transport links and living conditions. In the early 20th century, many factory workers lived in packed tenement blocks, often with large families. These tenements clustered on the Lower East Side, where population density has now dropped from at least 1,200 people per hectare to 600 or fewer. The rich, meanwhile, employed fleets of servants, making the average household far larger than it is today. 

Subway expansions, price rises and the razing of the city’s slums all helped push residents to other boroughs over the past century. As a result, far more people now work in Manhattan than live there. These density maps show the island’s current population densities by day and night:

Image: Joe Lertola, via Time Magazine.

As you can see, those red blocks don’t magically reappear in the visible portions of New Jersey or Brooklyn at the end of the working day – these city workers come from even further afield.

This ability to commute to the packed island, rather than attempting to live there, was massively boosted by the introduction of a subway system whose fares are part-publically subsidised. The first underground line opened in 1904. The network now covers pretty much the whole of New York City:


The island’s population recently began to rise again, so it remains to be seen which way the trend line will go. If flying cars take off, of course, no one will need to live on overpriced Manhattan real estate at all – it’ll just be a network of office blocks and landing strips. 

 
 
 
 

Which pairs of capital cities are the closest together?

Vienna, which is quite close to Bratislava, but not quite close enough. Image: Thomas Ledl

It doesn't take long to get from Paris to Brussels. An hour and a half on a comfortable Thalys train will get you there. 

Which raises an intriguing question, if you like that sort of thing: wich capital cities of neighbouring countries are the closest together? And which are the furthest away? 

There are some that one might think would be quite close, which are actually much further part. 

Buenos Aires, Argentina's capital, sits on one side of the estuary of the Río de la Plata, while Montevideo, Uruguay's capital lies on the other side. 

Click to expand: Image: Google Maps

But at 207km apart, they're not really that close at all. 

Similarly, Singapore – capital of, er, Singapore – always sticks in the mind as 'that bit on the end of the Malaysian sticky-out bit'. But it's actually pretty far away from Kuala Lumpur, Malaysia's capital. A whole 319km away, in fact:

Click to expand: Image: Google Maps

Thinking of 'countries that cause problems by being close together', you inevitably think of South Korea and North Korea. 

Click to expand: Image: Google Maps

And while Pyongyang in the North and Seoul in the South are pretty close together, 181km just isn't going to cut it. 

Time to do some Seoul-searching to find the real answer here.

(Sorry.)

(Okay, not that sorry.)

Another place where countries being close together tends to cause problems is the Middle East. Damascus, the capital of Syria, really isn't that far from Beirut, in Lebanon. Just 76km:

Click to expand: Image: Google Maps

Seeing as Lebanon is currently host to millions of refugees fleeing the horrors of Syria's never-ending civil war and the atrocities of Daesh, or Isis, this is presumably something that authorities in Beirut have given a certain amount of thought to.

Most of the time, finding nearby capitals is a game of searching out which bits of the world have lots of small countries, and then rooting around. So you'd think Central America would be ripe for close-together capital fun. 

And yet the best option is Guatemala and El Salvador – where the imaginatively named Guatemala City is a whole 179km away from the also imaginatively named San Salvador.  

Click to expand: Image: Google Maps

Another obvious place with lots of small-ish countries is Europe – the site of the pair of capitals that drove me to write this nonsense in the first place. 

Click to expand: Image: Google Maps

And in fairness, Vienna and Bratislava do make a pretty good showing of it. Austria's capital sits on the Danube; drift downstream, and you swiftly get to Slovakia's capital. As the crow flies, it's 56km – though as the man swims, it's a little longer. 

There are more surprising entries – particularly if you're willing to bend the rules a little bit. Bahrain and Qatar aren't really adjacent in the traditional sense, as they have no land border, but let's just go with it. 

Click to expand: Image: Google Maps

Manama, Bahrain's capital, is 140km away from Doha, the centre of the world's thriving local connecting-flight-industry which moonlights as Qatar's capital. 

Sticking with the maritime theme, Port of Spain in Trinidad and Tobago is 152km from St George's, Grenada. 

Click to expand: Image: Google Maps

Good, but not good enough. 

Castries, the capital of the Carribbean country of St Lucia, is 102km north of Kingstown, the capital of St Vincent and the Grenadines. 

Click to expand: Image: Google Maps

Better, but still not good enough. 

Basseterre, the capital of St Kitts and Nevis, inches ahead at 100km away from St John's, the capital of Antigua and Barbuda.

Click to expand: Image: Google Maps

But, enough teasing: it's time to get down to the big beasts.

If you ask Google Maps to tell you the distance between the capital of Congo and the Democratic Republic of the Congo, it comes up with a rather suspect 20km. 

 

Click to expand: Image: Google Maps

A short distance, but considering the only thing separating the two is the River Congo, something's up: Google places the centre of Brazzaville a little north of where it should be, and the centre of Kinshasa many many miles south of where it should be, in some sort of suburb.


So, in true CityMetric style, we turn to train stations. 

Though such transport hubs may not always perfectly mark the centre of a city – just ask London Oxford Airport or London Paddington – in this case it seems about right. 

Kinshasa's main train station is helpfully called 'Gare Centrale', and is almost slap-bang in the middle of the area Google marks as 'Centre Ville'. On the other side of the river, 'Gare de Brazzaville' is in the middle of lots of densely-packed buildings, and is right next to a Basilica, which is always a good sign. 

 

Click to expand: Image: Google Maps

And when marking that distance, you get a more realistic 4.8km. If you want to be really keen, the ferry between them travels 3.99km, and the closest point I could find between actual buildings was 1.74km, though admittedly that's in a more suburban area. 

Pretty close, though. 

But! I can hear the inevitable cries clamouring for an end to this. So, time to give the people what they want. 

Click to expand: Image: Google Maps

If you ask Google Maps to tell you how far away the Holy See, capital of the Vatican, is from Rome, capital of Rome, it says 3.5km. 

Click to expand: Image: Google Maps

If you set the centre of Rome to be the Palatine Hill, the ancient marking point for roads leading out of Rome, that narrows to 2.6km.

 

Click to expand: Image: Google Maps

Fiddle a bit and put the centre of the Vatican as, well, the middle bit of the roughly-circular Vatican, that opens up a smidge to 2.75km.

Click to expand: Image: Google Maps

Mark the centre of point of the Vatican as the approximate location of St Peter's Tomb within St Peter's Basilica, which is after all the main reason the Vatican is a thing and not just a quirky suburb of Rome, and 2.67km is your answer. 

Though obviously in practice Rome and the Vatican are as far away as one single step over the railings at the entrance of St Peter's Square, which fairly blatantly makes them the closest capital cities in the world. 

But that would have been a very boring thing to come out and say at the start. 

Oh, and if you hadn't worked it out already, the longest distance between a capital city and the capital of a country it shares a land border with is 6,395km. 

Click to expand: Image: Google Maps

I know it's tough for you, Vladimir and Kim. Long-distance relationships are a real struggle sometimes.

I can't make a pun work on either Moscow or Pyongyang here, but readers' submissions more than welcome. 

Jack May is a regular contributor to CityMetric and tweets as @JackO_May.

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