maps – Coffee Spoons

Fort Pitt

Yesterday I discussed some of the work at the Fort Pitt Museum in Pittsburgh, Pennsylvania. Specifically we looked at Fort Duquesne, the French fortification that guarded the linchpin of their colonies along the Saint Lawrence Seaway and the Mississippi and Ohio River valleys.

In 1753, the royal governor of Virginia dispatched a British colonial military officer, a lieutenant colonel, to demand the French withdraw from the chain of forts along the Allegheny River. The French politely refused. Undeterred, the lieutenant colonel, after returning the refusal, was sent with several dozen soldiers to push the British claim.

The lieutenant colonel discovered a French force south of present-day Pittsburgh. After largely surrounding the French force, the lieutenant colonel ordered his soldiers to open fire and in the ensuing battle the French force was destroyed by killing or capturing the vast majority of the force. That was the opening battle of the Seven Years War, a global conflict that stretched across North America, South America, Africa, India, and Asia.

The lieutenant colonel who started it all? George Washington.

At the war’s outset, Washington was involved—but did not lead—in another operation to oust the French from Fort Duquesne. This operation failed spectacularly with the death of its commander, Major General Edward Braddock. Three years later, British forces had sufficiently regrouped that they again attempted to take Fort Duquesne. After some tactical losses, the British continued to press the French. The French, seeing the vastly superior numbers of British soldiers, decided to withdraw and in blowing up their ammunition stores, destroyed Fort Duquesne.

The British, operationally commanded by Lieutenant Colonel Henry Bouquet, a Swiss-born veteran British officer, occupied the smoldering ruins. There they proceeded to build an even larger fortification named after the British prime minister who ordered the site taken. The prime minister? William Pitt the Elder. The fort? Fort Pitt. The town that would develop around the fort? Pittsburgh.

When completed, Fort Pitt was the largest and most sophisticated British fortification west of the Appalachian Mountains. It guarded British colonial interests from both French and native forces who would have gladly retaken control of the area.

Today the Fort Pitt Museum has several diagrams and dioramas detailing what was at its completion. The photograph below is a reproduction of a diagram made in 1761 just prior to the fort’s completion of the fort and its immediate environs. Even the reproduction is itself a reproduction in that the creators used the same materials and methods as would have been used in the 18th century, lending it some of that aged quality.

To be clear, this is large at least maybe six feet wide.

And here we have a closer view of the fort itself. If you look closely to the left, nearer the forks of the Ohio, you can see the outline of the far smaller Fort Duquesne.

You can see more of the details in this shot.

But for me the amazing part was walking into the museum where you are greeted with an amazing diorama of the Fort as it appeared in 1765. You can already see the emerging town of Pittsburgh outside the fortifications.

Credit for the original diagram goes to British military engineer Bernard Ratzer, its recreation was made by artists from the Carnegie Museum.

Credit for the diorama goes to Holiday Displays.

Diagramming and Diorama-ing Fort Duquesne

Pittsburgh exists because of the city sits at the confluence of the Allegheny, Monongahela, and Ohio Rivers. As far back as the early 18th century, English and French colonists had recognised the strategic value of the site and as imperial ambitions ramped up, the French finally wrested control of the area from the English and constructed a fort to defend the forks of the Ohio. They named it Fort Du Quesne (now Fort Duquesne) after Governor-General of New France, Marquis Du Quesne.

Fort Duquesne anchored a north-south chain of French forts linking the Ohio River to Lake Erie via the Allegheny River. Since the Allegheny drains into the Ohio and not Lake Erie, the French used a navigable tributary of the Allegheny, the imaginatively named French Creek, to reach just a few miles from the fort on Lake Erie, Fort Presque Isle, from which they portaged overland to Fort Le Bœuf. From there they travelled down the river or overland via the Venango Path to Fort Machault situated at the confluence of French Creek and the Allegheny River.

This chain of forts and the control they established over the Ohio allowed the French to link their colony of New France in present day Québec along the Saint Lawrence River to their colonies along the Mississippi in the Illinois Country via Lake Erie then the Allegheny and Ohio Rivers, which feed into the Mississippi River. The Mississippi of course then empties into the Gulf of Mexico through the then French colony of Louisiana and New Orleans. Strategically this allowed the French to surround and choke the British colonies along the eastern seaboard from territory and resources west of the Appalachian Mountains.

At the site of Fort Duquesne on what is now called Point State Park, a granite stone outline of the original French fort sits in a grass field. And at the centre of the outline is a plaque diagramming the fort’s design.

The marker for the centre of Fort Duquesne

Thankfully for history lovers, the park also contains a history museum dedicated to Fort Pitt, the larger British successor fortification to Fort Duquesne. But inside, the history of Fort Pitt would be incomplete without a discussion of Fort Duquesne and that includes a nice diorama. You will note more details here, however, as the initial fort seen in the above diagram was expanded to include more area for barracks, farms, and ancillary activities like forges.

But even still a closer shot of the fort itself shows what the physical buildings would have looked like above and beyond a two-dimensional diagram.

Having been to the site, however, you can see that Fort Duquesne and the later Fort Pitt weren’t necessarily as defensible as one may think. Just to the south across the Monongahela River is a ridgeline that offers clear lines of fire into the forts. Some well positioned artillery would have made holding the forts tenuous at best. Of course hauling artillery and ammunition up to the ridge’s summit is easier said than done. Here’s a photo from the Fort Pitt Museum, whose exterior walls reconstruct one of the later Fort Pitt’s bastion walls. You can see in the background the ridge line of Mount Washington (originally named Coal Hill) stands far above the fort’s defences. Artillery could easily angle down and fire into the forts, be them either Duquesne or Pitt.

It would have been like fish in a barrel.

Credit for the marker goes to I assume the designers at the Pennsylvania State Park commission.

Credit for the dioramas goes to Holiday Displays, who created the originals in the 1960s.

We’re a Long Way from Kansas

I had something else for today, but this morning I opened the door and found my morning paper. Nothing terribly special. No massive headline. No large front-page graphic. See what I mean?

But then as I bent down to pick it up, I spotted a little tree map. But it turned out it wasn’t a tree map. It was a rectangle, largely, but it was actually a county map of Kansas. It was so small it fit within a single column.

The map showed those counties that had a majority vote in favour of keeping abortion rights. And then those counties that also voted for Trump in 2020 were outlined in orange—a good colour pairing. Turned out a number of counties did.

Without wading into the politics of it, because that’s a separate article, this was a great little map. It didn’t need to be crazy complicated or even large.

Credit for the piece goes to the New York Times graphics department.

Europe By Rail

Many of us have pent up travel demand. Covid-19 remains with us, lingering in the background, but it’s largely from our front-of-mind. For those of my readers in Europe, or just curious how superior European rail infrastructure is over American, this piece from Benjamin Td provides some useful information.

It uses isochrones to map out how much a traveller could travel if he would travel five hours. For this screenshot I chose London’s King’s Cross station. In red we see distances within a one-hour rail ride from said station. In the lightest yellow are those places within the five-hour distance.

The interactive map allows users to investigate stations throughout Europe. Mousing over various parts brings up different stations. Clicking on the station freezes the station on the map allowing the user to zoom in or out and investigate different areas of Europe.

Colour-wise, things work well. The desaturated map allows the yellow-to-red palette to shine. And to the right a closable legend, which unfortunately cannot be reopened once closed for the only real blemish on the piece. Even typographically, the labels appear in grey whereas selected stations appear in black.

A well done piece.

Credit for the piece goes to Benjamin Td.

A New Downtown Arena for Philadelphia?

I woke up this morning and the breaking news was that the local basketball team, the 76ers, proposed a new downtown arena just four blocks from my office. The article included a graphic showing the precise location of the site.

I have no doubt whatsoever this won’t impact my commutes.

For our purposes this is just a little locator map in a larger article. But I wanted to draw attention to two things in an otherwise nice map. First, if you look carefully on the left you can see the label for the Broad Street Line placed over the actual railway line, which is what makes it so difficult to read. I probably would have shifted the label to the left to increase its legibility.

Second, and this is a common for maps of Philadelphia, is the actual north-south route of said Broad Street Line, one of the three subway lines running in the city. (You all know of the Broad Street and Market–Frankford Elevated, but don’t forget the PATCO.) If you look closely enough it appears to run directly underneath Broad Street in a straight line. But where it passes beneath City Hall you will see the little white dot locating the station is placed to the left of the railway line.

Why is that?

Well when it was built, Philadelphia’s City Hall was the tallest habitable building in the world. Whilst clearly supplanted in that record, the building remains the largest free-standing masonry building in the world. But that means it has deep and enormous foundations. Foundations that could not be disturbed when the city was running a subway line directly beneath Broad Street.

Consequently, the Broad Street Line is not actually straight—ride it heading south into City Hall Station and you’ll notice the sharp turn both in its bend and the loud screeching of metal. The line bends around parts of the building’s foundations, sharply on the north side and more gently on the south side. So the actual station is still beneath City Hall, but offset to the west.

But most of the time it’s easier just to depict the route as a straight line running directly beneath City Hall.

Credit for the piece goes to John Duchneskie.

Small Dog Days of Summer

For my readers in the northern hemisphere, which is the vast majority of you, we are in the middle of meteorological summer, the dog days. And whilst my UK and Europe readers continue to bake under temperatures greater than 40ºC (104ºF), the northeast United States and Philadelphia in particular is looking at a heatwave starting today that’s forecast to peak at a temperature of 38ºC (100ºF) this weekend and a heat index reaching 41ºC (106ºF) tomorrow.

Not cool.

Yesterday we examined a completely different topic, property tax increases in Philadelphia, but we contrasted that work with a heat index map from the New York Times. With the heatwave beginning this afternoon, however, it seemed apropos to revisit that contrasting article.

It begins with the map that we looked at yesterday. Of course yesterday was Tuesday. Today is Wednesday, and so you can already compare these two maps to see how and where the heat has shifted. Spoiler: the Southeast and Midwest.

It does so with a nice simple three-colour unidirectional spectrum from a light yellow to a burnt orange. And you can see the orange spreading up from the Gulf Coast and along the southeastern Atlantic Seaboard.

For those not familiar, the heat index is basically what the air “feels like” taking into consideration the actual temperature and the relative humidity in the air. Humans cool themselves via perspiration and when the air is excessively humid our ability to perspire decreases and thus the body begins to run hotter. Warmer temperatures allow the atmosphere to increase the amount of moisture it can contain and you can see all that Gulf and subtropical moisture carrying itself into the hot air moving up from the south.

Very not cool.

The piece also offers a look at the forecast for the heat index, showing the next six days. These small multiples allow the reader to see the geographic progression of the heat. Whereas today will be particularly for parts of the Midwest in southern Illinois and Indiana, tomorrow will see the worst for the Eastern Seaboard. Luckily the heat index retreats a bit, though as I noted above, the temperatures will continue to rise until Sunday, meaning higher temperatures, but lower relative humidity. For Philadelphia in particular we talking about 50% relative humidity tomorrow and only 35% on Sunday. That makes a big difference.

Overall this is a great piece despite the content.

Personally, I just can’t wait until summer.

Credit for the piece goes to Matthew Bloch, Lazaro Gamio, Zach Levitt, Eleanor Lutz, and John-Michael Murphy.

Legendary Adjustments

The other day I was reading an article about the coming property tax rises in Philadelphia. After three years—has anything happened in those three years?—the city has reassessed properties and rates are scheduled to go up. In some neighbourhoods by significant amounts. I went down the related story link rabbit hole and wound up on a Philadelphia Inquirer article I had missed from early May that included a map of just where those increases were largest. The map itself was nothing crazy.

We have a choropleth with city zip codes coloured by the percentage increase. I was thrown for a bit of a loop as I immediately perceived the red representing lower values and green higher values, the standard green to red palette. But given that higher values are “bad”, I can live red representing bad and sitting at the top of the spectrum.

I filed it away to review later, but when I returned I visited on my mobile phone. And what I saw broadly looked the same, but there was a disconcerting difference. Take a look at the legend.

You can see that instead of running vertically like it did on the desktop, now the legend runs horizontally across the bottom. In and of itself, that’s not the issue. Though I do wonder if this particular legend could have still worked in roughly the same spot/alignment given the geographic shape of Philadelphia along the Delaware River.

Rather look at the order. We go from the higher, positive values on the left to the negative, lower values on the right. When you read the legend, this creates some odd jumps. For example, we move from “+32% to +49%” then to “+15% to +31%”. We would normally say something to the point of the increase bins moving from “+15% to +31%” then to “+32% to +49%”. In other words, the legend itself is a continuum.

The fix for this would be to simply flip the running order of the legend. Put the lower values on the left and then step up to the right. For a quick comparison, I visited the New York Times website and pulled up the first graphic I could find that looked like a choropleth. Here we have a map of the dangerous temperatures across the United States.

Note how here the New York Times also runs their legend horizontally below the graphic. But instead of running high-to-low like in the Inquirer, the Times runs low-to-high, making for a more natural and intuitive legend.

This kind of simple ordering change would make the Inquirer’s map that much better.

Credit for the Inquirer piece goes to Kasturi Pananjady and John Duchneskie.

Credit for the Times piece goes to Matthew Bloch, Lazaro Gamio, Zach Levitt, Eleanor Lutz, and John-Michael Murphy.

Choo Choo

I took two weeks off as work was pretty crazy, but we’re back to covering data visualisation and design with a graphic about trains. And anybody who knows me knows how I love trains. One of the early acts of the Biden administration was funding a proper expansion of rail service in the United States.

Last week the Washington Post published an article that explored some of the difficulties Amtrak, the national rail company, faces in that expansion. Most of it has to deal with the fact that outside the Northeast Amtrak largely uses rail lines owned by freight companies.

The article uses a map to show Amtrak routes and, in particular, where Amtrak wants to increase service or create new service.

As far as the map goes, it does a nice job needing not to reinvent the wheel. When an existing route will have expanded service, e.g. the Northeast Corridor, the blue line sits next to the dotted white line. What remains a bit unclear to me is the use of black text for Chicago, Atlanta, Dallas, and Los Angeles. The bold type for New Orleans and Mobile makes sense because of the story’s focus on that particular route. Chicago is mentioned once, but Dallas is not. So that is unclear.

But what really stood out to me was what happened when I re-read the story on my mobile. The graphic split from a full map to three narrow graphics, each featuring 1/3 of the United States. The designers moved the text labels so that they are fully visible in each graphic.

Overall, the piece does a great job at showing the map, but in particular it shines when it swaps out the large map for the smaller graphics on small screens. And the attention to detail in moving the text labels makes it all the better.

Credit for the piece goes to Luz Lazo.

Turn Down the Heat

First, as we all should know, climate change is real. Now that does not mean that the temperature will always be warmer, it just means more extreme. So in winter we could have more severe cold temperatures and in hurricane season more powerful storms. But it does mean that in the summer we could have more frequent and hotter heat waves.

Enter the United States, or more specifically the North American continent. In this article from the BBC we see photographs of the way the current heatwave is playing out across the continent. But it opens up with a nice map. Well, nice as in nicely done, not as in this is actually nice weather.

The only complaint most of my American readers might have is that the numbers make no sense. That’s because it’s all in Celsius. Unfortunately for Americans most of the rest of the world uses Celsius and not Fahrenheit. Suffice it to say you don’t want to be in the dark reds. 44C equals 111F. 10C, the greenish-yellow side of the spectrum, is a quite pleasant 50F.

And that can relate to a small housekeeping note. I’m back after a long weekend up in the Berkshires. I took a short holiday to go visit the area near that north–south band of yellow over the eastern portion of the United States. It was very cool and windy and overall a welcome respite from the heat that will be building back in here across the eastern United States later this week.

At least yesterday was the summer solstice. The days start getting shorter. And in about five weeks or so we will reach the daily average peak temperature here in Philadelphia. At that point the temperatures begin cooling towards their eventual mid-January nadir.

I can’t wait.

Credit for the piece goes to the BBC graphics department.

New Mexico Burns

Editor’s note: I was having some technical issues last week. This was supposed to post last week.

Editor’s note two: This was supposed to go up on Monday. Still didn’t. Third time’s the charm?

Yesterday I wrote about a piece from the New York Times that arrived on my doorstep Saturday morning. Well a few mornings earlier I opened the door and found this front page: a map of the western United States highlighting the state of New Mexico.

That doesn’t exactly look like a climate I’d enjoy.

Unlike the graphic we looked at yesterday, this graphic stretched down the page and below the fold, not by much, but still notably. The maps are good and the green–red spectrum passes the colour blind test. How the designer chose to highlight New Mexico is subtle, but well done. As the temperature and precipitation push towards the extreme, the colours intensify and call attention to those areas.

Also unlike the graphic we looked at yesterday, this piece contained some additional graphics on the inside pages.

Definitely not a place where I want to be.

These are also nicely done. Starting with the line chart at the bottom of the page, we can contrast this to some of the charts we looked at yesterday.

Here the designer used axis lines and scales to clearly indicate the scale of New Mexico’s wildfire problem. Not only can you see that the number of fires detected has spiked far above than the number in the previous years back to 2003. And not only is the number greater, the speed at which they’ve occurred is noticeably faster than most years. The designer also chose to highlight the year in question and then add secondary importance to two other bad years, 2011 and 2012.

The other graphics are also maps like on the front page. The first was a locator map that pointed out where the fires in question occurred. Including one isn’t much of a surprise, but what this does really nicely is show the scale of these fires. They are not an insignificant amount of area in the state.

Pointing out where I really don’t want to be in New Mexico.

Finally we have the main graphic of the piece, which is a map of the spread of the Calf Canyon and Hermits Peak fire, which was two separate fires until they merged into one. The article does a good job explaining how part of the fire was actually intentionally set as part of a controlled burn. It just became a bit uncontrolled shortly thereafter.

This reminded me of a piece I wrote about last autumn when the volcano erupted on La Palma. In that I looked at an article from the BBC covering the spread of the lava as it headed towards the coast. In that case darker colours indicated the earlier time periods. Here the Times reversed that and used the darker reds to indicate more recent fire activity.

Overall the article does a really nice job showing just what kind of problems New Mexico faces not just now from today’s environmental conditions, but also in the future from the effects of climate change.

Credit for the piece goes to Guilbert Gates, Nadja Popovich, and Tim Wallace.