Why Are So Many Blackboards Green?

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Though the term blackboard has a color right there in its name, most of them aren’t actually black. While we still use the term more or less interchangeably with chalkboards, blackboards tend to be green. Why the difference? Why call a surface a blackboard if it's green?

Because 200 years ago, blackboards were black. According to author Lewis Buzbee’s Blackboard: A Personal History of the Classroom, large boards of connected slates that teachers could write on for the whole class to see didn’t come around until the early 1800s, and the name blackboard wasn’t used until 1815. They were made with slate, or in rural areas, they were often just wooden boards painted dark with egg whites mixed with the remains of charred potatoes. Later, they were also made of wood darkened with a commercially made porcelain-based ink. They were, true to their name, black.

And the relatively affordable, ubiquitous technology was a huge success, changing education forever. By the mid-19th century, even the most rural schools had a blackboard.

As an 1841 teaching manual, The Blackboard in the Primary School, put it: “The inventor or introducer of the black-board system deserves to be ranked among the best contributors to learning and science, if not among the greatest benefactors of mankind.”

In the 20th century, blackboards began to look a little different, though the idea was the same. In the 1930s, manufacturers began to make chalkboards using a green, porcelain enameled paint on a steel base. By the 1960s, the green chalkboard trend was in full swing. Teachers had discovered that a different colored paint was a lot more comfortable to stare at all day, because green porcelain paint cut down on glare. By and large, many blackboards were slowly replaced by their green brethren. (Apparently, greenboards wasn’t quite as catchy of a name, though, so the term blackboard stuck.)

But today, many school children might not be familiar with either blackboards or "greenboards." In the 1990s, schools began converting their classrooms to whiteboards, which produce less dust (and eliminate that terrible screeching noise). According to The Atlantic, at the turn of the millennium, whiteboards were outselling chalkboards by a 4-to-1 ratio.

You can still find the occasional blackboard in a classroom, though—even if it’s just decorative. And some schools are rediscovering blackboards, literally. In the summer of 2015, construction workers renovating an Oklahoma school for smart whiteboards found two historic slate blackboards that still bore drawings from almost 100 years ago.

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Presidents Day vs. President's Day vs. Presidents' Day: Which One Is It?

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Happy Presidents’ Day! Or is it President’s Day? Or Presidents Day? What you call the national holiday depends on where you are, who you’re honoring, and how you think we’re celebrating.

Saying "President’s Day" implies that the day belongs to a singular president, such as George Washington or Abraham Lincoln, whose birthdays are the basis for the holiday. On the other hand, referring to it as "Presidents’ Day" means that the day belongs to all of the presidents—that it’s their day collectively. Finally, calling the day "Presidents Day"—plural with no apostrophe—would indicate that we’re honoring all POTUSes past and present (yes, even Andrew Johnson), but that no one president actually owns the day.

You would think that in the 140 years since "Washington’s Birthday" was declared a holiday in 1879, someone would have officially declared a way to spell the day. But in fact, even the White House itself hasn’t chosen a single variation for its style guide. They spelled it “President’s Day” here and “Presidents’ Day” here.


Wikimedia Commons // Public Domain

Maybe that indecision comes from the fact that Presidents Day isn’t even a federal holiday. The federal holiday is technically still called “Washington’s Birthday,” and states can choose to call it whatever they want. Some states, like Iowa, don’t officially acknowledge the day at all. And the location of the punctuation mark is a moot point when individual states choose to call it something else entirely, like “George Washington’s Birthday and Daisy Gatson Bates Day” in Arkansas, or “Birthdays of George Washington and Thomas Jefferson” in Alabama. (Alabama loves to split birthday celebrations, by the way; the third Monday in January celebrates both Martin Luther King Jr. and Robert E. Lee.)

You can look to official grammar sources to declare the right way, but even they don’t agree. The AP Stylebook prefers “Presidents Day,” while Chicago Style uses “Presidents’ Day.”

The bottom line: There’s no rhyme or reason to any of it. Go with what feels right. And even then, if you’re in one of those states that has chosen to spell it “President’s Day”—Washington, for example—and you use one of the grammar book stylings instead, you’re still technically wrong.

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Full vs. Queen Mattress: What's the Difference?

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iStock.com/IPGGutenbergUKLtd

If you’re in the market for a new mattress this Presidents Day weekend (the holiday is traditionally a big one for mattress retailers), one of the first decisions you’ll need to make is regarding size. Most people know a king mattress offers the most real estate, but the difference between a full-sized mattress and a queen-sized one provokes more curiosity. Is it strictly a matter of width, or are depth and length factors? Is there a recommended amount of space for each slumbering occupant?

Fortunately, mattress manufacturers have made things easier by adhering to a common set of dimensions, which are sized as follows:

Crib: 27 inches wide by 52 inches long

Twin: 38 inches wide by 75 inches long

Full: 53 inches wide by 75 inches long

Queen: 60 inches wide by 80 inches long

King: 76 inches wide by 80 inches long

Depth can vary across styles. And while you can find some outliers—there’s a twin XL, which adds 5 inches to the length of a standard twin, or a California king, which subtracts 4 inches from the width and adds it to the length—the four adult sizes listed above are typically the most common, with the queen being the most popular. It's 7 inches wider than a full (sometimes called a “double”) mattress and 5 inches longer.

In the 1940s, consumers didn’t have as many options. Most people bought either a twin or full mattress. But in the 1950s, a post-war economy boost and a growing average height for Americans contributed to an increasing demand for larger bedding.

Still, outsized beds were a novelty and took some time to fully catch on. Today, bigger is usually better. If your bed is intended for a co-sleeping arrangement with a partner, chances are you’ll be looking at a queen. A full mattress leaves each occupant only 26.5 inches of width, which is actually slightly narrower than a crib mattress intended for babies and toddlers. A queen offers 30 inches, which is more generous but still well below the space provided by a person sleeping alone in a twin or full. For maximum couple comfort, you might want to consider a king, which is essentially like two twin beds being pushed together.

Your preference could be limited by the size of your bedroom—you might not be able to fit a nightstand on each side of a wider bed, for example—and whether you’ll have an issue getting a larger mattress up stairs and/or around tricky corners. Your purchase will also come down to a laundry list of options like material and firmness, but knowing which size you want helps narrow down your choices.

One lingering mystery remains: Why do we tend to shop for mattresses on Presidents Day weekend? One reason could be time. The three-day weekend is one of the first extended breaks since the December holidays, giving people an opportunity to trial different mattress types and deliberate with a partner. Shopping Saturday and Sunday allows people to sleep on it before making a decision.

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