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Toys, Trampling and Tragedy: The Victoria Hall Disaster

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Wikipedia

If this year’s Black Friday is like any other, too many people will crowd into stores and trample over each other to get a deal on some Christmas presents. People will get hurt. Someone might even get killed. These types of incidents, where a rush for goods can turn into tragedy, aren’t anything new. One of the most infamous—a stampede for toys in 19th century England—left 183 children dead. 

On June 16, 1883, the Victoria Hall in Sunderland, England hosted what was billed as the “greatest treat for children ever given.” The Fays of Tynemouth—“conjurer” Alexander Fay and his sister Annie the “enchantress”—had come to town to perform their variety show, featuring magic tricks, waxworks, “living marionettes” and their “Great Ghost Illusion.” Some 2000 tickets had been sold, and most of the seats were filled with children. 

At the end of the performance, a special announcement was made: children holding certain numbered tickets would receive a free toy when they exited the hall, the Fays would distribute toys to other children from the stage and another man would take toys to the upper seating gallery. 

When the kids in the upper gallery heard that, they “obligingly rose en masse and went down the stairs to meet him,” remembered William Codling, was six when he attended the show. 

“I raced up the gallery as fast as I could, scrambled with the crowd through the doorway and jolted my way down two flights of stairs. Here the crowd was so compressed that there was no more racing but we moved forward together, shoulder to shoulder. Soon we were most uncomfortably packed but still going down.” 

At the bottom of the stairwell there was a problem. The door to the arena had been partially opened and then bolted, leaving only a space of about two feet to squeeze through. Only one person could get through at a time; the door might have been jammed this way to control movement into the lower level and make ticket-checking easier. There was no staff at the door to organize a line, though, and the mass of kids coming from the gallery were flooding down the stairs and rushing the door. The first few children who got down the stairs managed to squeeze through the doorway, but as more and more came down the exit got blocked. The stampede didn’t stop and as the kids in the back kept pushing forward, those at the bottom, unable to open the door any wider, were trapped underneath the weight of the crowd. 

“Suddenly I felt that I was treading upon someone lying on the stairs and I cried in horror to those behind, ‘Keep back, keep back! There’s someone down’,” Codling remembered. “It was no use, I passed slowly over and onwards with the mass and before long I passed over others without emotion. At last we came to a dead stop but still those behind came crowding on…”

“Children tumbled head over heels,” reported another witness. “The heap became higher and higher, until it became a mass of dying children over six feet in height.”

When the adults in the theater realized what was happening, they tried to pull the door open all the way, but the bolt was on the children’s side. Some adults ran up another staircase into the gallery to try and get the children still on the stairs to come back up.

“Then the pressure began to lessen,” Codling said. “A report spread that the toys were being distributed in the gallery and those behind having made a feeble rush upwards, back we tottered across that path of death. ... At the first landing we were met by some men and taken out of doors into the open air…Soon men began to come down the steps bearing in their arms lifeless burdens, and from the crowd came a wail of grief…”

In the end, 183 children between the ages of 3 and 14 died from being crushed and asphyxiated. Shock rippled through the whole country and a disaster fund raised 5000 pounds to pay for all the children’s funerals. Queen Victoria sent condolences to all the families and made her own donation to the funeral costs. Through the entire week that the funerals were held, businesses in Sunderland stayed closed as a sign of respect and mourning. The money that was left over from the fund was used to erect a memorial statue that stood in a park across from the hall, which was leveled during a German air raid during World War II. 

Parliament made two investigations into the Victoria Hall disaster, but failed to find who was responsible for bolting the door the way that they did. The tragedy did result in some good, though; the government issued new laws that required “places of public entertainment” to have a sufficient number of exits with doors that could easily open outward, leading to the development of the push-bar emergency exit.

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iStock // Ekaterina Minaeva
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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8 Common Dog Behaviors, Decoded
May 25, 2017
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Dogs are a lot more complicated than we give them credit for. As a result, sometimes things get lost in translation. We’ve yet to invent a dog-to-English translator, but there are certain behaviors you can learn to read in order to better understand what your dog is trying to tell you. The more tuned-in you are to your dog’s emotions, the better you’ll be able to respond—whether that means giving her some space or welcoming a wet, slobbery kiss. 

1. What you’ll see: Your dog is standing with his legs and body relaxed and tail low. His ears are up, but not pointed forward. His mouth is slightly open, he’s panting lightly, and his tongue is loose. His eyes? Soft or maybe slightly squinty from getting his smile on.

What it means: “Hey there, friend!” Your pup is in a calm, relaxed state. He’s open to mingling, which means you can feel comfortable letting friends say hi.

2. What you’ll see: Your dog is standing with her body leaning forward. Her ears are erect and angled forward—or have at least perked up if they’re floppy—and her mouth is closed. Her tail might be sticking out horizontally or sticking straight up and wagging slightly.

What it means: “Hark! Who goes there?!” Something caught your pup’s attention and now she’s on high alert, trying to discern whether or not the person, animal, or situation is a threat. She’ll likely stay on guard until she feels safe or becomes distracted.

3. What you’ll see: Your dog is standing, leaning slightly forward. His body and legs are tense, and his hackles—those hairs along his back and neck—are raised. His tail is stiff and twitching, not swooping playfully. His mouth is open, teeth are exposed, and he may be snarling, snapping, or barking excessively.

What it means: “Don’t mess with me!” This dog is asserting his social dominance and letting others know that he might attack if they don’t defer accordingly. A dog in this stance could be either offensively aggressive or defensively aggressive. If you encounter a dog in this state, play it safe and back away slowly without making eye contact.

4. What you’ll see: As another dog approaches, your dog lies down on his back with his tail tucked in between his legs. His paws are tucked in too, his ears are flat, and he isn’t making direct eye contact with the other dog standing over him.

What it means: “I come in peace!” Your pooch is displaying signs of submission to a more dominant dog, conveying total surrender to avoid physical confrontation. Other, less obvious, signs of submission include ears that are flattened back against the head, an avoidance of eye contact, a tongue flick, and bared teeth. Yup—a dog might bare his teeth while still being submissive, but they’ll likely be clenched together, the lips opened horizontally rather than curled up to show the front canines. A submissive dog will also slink backward or inward rather than forward, which would indicate more aggressive behavior.

5. What you’ll see: Your dog is crouching with her back hunched, tail tucked, and the corner of her mouth pulled back with lips slightly curled. Her shoulders, or hackles, are raised and her ears are flattened. She’s avoiding eye contact.

What it means: “I’m scared, but will fight you if I have to.” This dog’s fight or flight instincts have been activated. It’s best to keep your distance from a dog in this emotional state because she could attack if she feels cornered.

6. What you’ll see: You’re staring at your dog, holding eye contact. Your dog looks away from you, tentatively looks back, then looks away again. After some time, he licks his chops and yawns.

What it means: “I don’t know what’s going on and it’s weirding me out.” Your dog doesn’t know what to make of the situation, but rather than nipping or barking, he’ll stick to behaviors he knows are OK, like yawning, licking his chops, or shaking as if he’s wet. You’ll want to intervene by removing whatever it is causing him discomfort—such as an overly grabby child—and giving him some space to relax.

7. What you’ll see: Your dog has her front paws bent and lowered onto the ground with her rear in the air. Her body is relaxed, loose, and wiggly, and her tail is up and wagging from side to side. She might also let out a high-pitched or impatient bark.

What it means: “What’s the hold up? Let’s play!” This classic stance, known to dog trainers and behaviorists as “the play bow,” is a sign she’s ready to let the good times roll. Get ready for a round of fetch or tug of war, or for a good long outing at the dog park.

8. What you’ll see: You’ve just gotten home from work and your dog rushes over. He can’t stop wiggling his backside, and he may even lower himself into a giant stretch, like he’s doing yoga.

What it means: “OhmygoshImsohappytoseeyou I love you so much you’re my best friend foreverandeverandever!!!!” This one’s easy: Your pup is overjoyed his BFF is back. That big stretch is something dogs don’t pull out for just anyone; they save that for the people they truly love. Show him you feel the same way with a good belly rub and a handful of his favorite treats.

The best way to say “I love you” in dog? A monthly subscription to BarkBox. Your favorite pup will get a package filled with treats, toys, and other good stuff (and in return, you’ll probably get lots of sloppy kisses). Visit BarkBox to learn more.

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