Why Are So Many Blackboards Green?

iStock
iStock

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.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

How Does Alberta, Canada, Stay Rat-Free?

Francisco Martins/iStock via Getty Images
Francisco Martins/iStock via Getty Images

David Moe:

Alberta is the only province in Canada that does not have any rats and is, in fact, the largest inhabited area on the planet that is rat-free. Rats had to come from Eastern Canada, and it’s a long walk, so it was not until the 1950s that they finally reached Alberta. When they did, the Alberta government was ready for them: They instituted a very aggressive rat control program that killed every single rat that crossed the Alberta/Saskatchewan border.

The Agricultural Pests Act of Alberta, 1942 authorized the Minister of Agriculture to designate as a pest any animal that was likely to destroy crops or livestock; every person and municipality had to destroy the designated pests. Where their pest control was not adequate, the provincial government could carry it out and charge the costs to the landowner or municipality.

Rats were designated as pests in 1950. An amendment to the act in 1950 further required that every municipality appoint a pest control inspector. In 1951, conferences on rat control were held in eastern Alberta, and 2000 posters and 1500 pamphlets titled "Rat Control in Alberta" were distributed to grain elevators, railway stations, schools, post offices, and private citizens.

Between June 1952 and July 1953, [more than 140,000 pounds] of arsenic trioxide powder were used to treat 8000 buildings on 2700 farms in an area 12 to 31 miles wide and 186 miles long on the eastern border. Some residents were not informed that arsenic was being used and some, allegedly, were told that the tracking powder was only harmful to rodents. Consequently, some poisoning of livestock, poultry, and pets occurred. Fortunately, Warfarin—the first anticoagulant rodent poison—became available in 1953; Warfarin is much safer than arsenic, and in fact is prescribed to some heart patients as a blood thinner.

The number of rat infestations in the border area increased rapidly from one in 1950 to 573 in 1955. However, after 1959, the numbers of infestations dropped dramatically.

The provincial share of rat control expenses increased to 100 percent in 1975. All premises within the control zone from Montana to Cold Lake are now inspected at least annually. Rat infestations are eliminated by bait, gas, or traps. Buildings are occasionally moved or torn down, and in some cases, rats are dug out with a backhoe or bulldozer. In the early days they also used shotguns, incendiaries, and high explosives to control rats. It was something of a war zone.

Hundreds of suspected infestations are reported each year, but most sightings turn out to be muskrats, pocket gophers, ground squirrels, bushy-tailed wood rats, or mice. However, all suspected infestations are investigated.

A few white rats have been brought in by pet stores, biology teachers, and well-meaning individuals who did not know it was unlawful to have rats in Alberta, even white lab rats or pet rats. White rats can only be kept by zoos, universities, colleges, and recognized research institutions in Alberta. Private citizens may not keep white rats, hooded rats, or any of the strains of domesticated Norway rats. Possession of a pet rat can lead to a fine of up to $5000.

In 2004 someone released 38 rats in Calgary. By the time the rat control officers arrived, most of them were dead. The local residents had formed a posse and killed them with brooms, 2x4s, and shovels. If the authorities had caught the culprit, he could have faced a $190,000 fine (38 x $5000)—assuming his neighbors didn’t get to him with brooms, 2x4s, and shovels first. Albertans don’t want rats.

This post originally appeared on Quora. Click here to view.

Why Do Students Get Summers Off?

Iam Anupong/iStock via Getty Images
Iam Anupong/iStock via Getty Images

It’s commonly believed that school kids started taking summers off in the 19th century so that they’d have time to work on the farm. Nice as that story is, it isn’t true. Summer vacation has little to do with tilling fields and more to do with sweaty, rich city kids playing hooky—and their sweaty, rich parents.

Before the Civil War, farm kids never had summers off. They went to school during the hottest and coldest months and stayed home during the spring and fall, when crops needed to be planted and harvested. Meanwhile, city kids hit the books all year long—summers included. In 1842, Detroit’s academic year lasted 260 days.

But as cities got denser, they got hotter. Endless lanes of brick and concrete transformed urban blocks into kilns, thanks to what was known as the “urban heat island effect.” That’s when America’s swelling middle and upper class families started hightailing it to the cooler countryside. And that caused a problem. School attendance wasn’t mandatory back then, and classrooms were being left half-empty each summer. Something had to give.

Legislators, in one of those if-you-can’t-beat-‘em-join-‘em moments, started arguing that kids should get summers off anyway. It helped that, culturally, leisure time was becoming more important. With the dawn of labor unions and the eight-hour workday, working adults were getting more time to themselves than ever before. Advocates for vacation time also argued (incorrectly) that the brain was a muscle, and like any muscle, it could suffer injuries if overused. From there, they argued that students shouldn’t go to school year-round because it could strain their brains. To top it off, air conditioning was decades away, and city schools during summertime were miserable, half-empty ovens.

So by the turn of the century, urban districts had managed to cut about 60 schooldays from the most sweltering part of the year. Rural schools soon adopted the same pattern so they wouldn’t fall behind. Business folks obviously saw an opportunity here. The summer vacation biz soon ballooned into what is now one of the country’s largest billion-dollar industries.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER