Inside the World's Only Public Collection of Mechanical Puzzles

Jennifer Jameson, Flickr // CC BY-NC-ND 2.0 (cropped)
Jennifer Jameson, Flickr // CC BY-NC-ND 2.0 (cropped)

Calling all problem-solvers and puzzle masters: A library in Bloomington, Indiana, is home to the world's only public display of mechanical puzzles. The Jerry Slocum Mechanical Puzzle Collection can be found at Indiana University’s Lilly Library, which also houses rare books and manuscripts, including Queen Elizabeth I's Great Seal and an early printed copy of "The Star Spangled Banner."

The collection is named after Jerry Slocum, a Chicago-area native who started donating his personal collection of puzzles to the library in 2006. The library now has over 34,000 mechanical puzzles, which, unlike jigsaw and crossword puzzles, tend to feature interconnected pieces that must be physically manipulated in order to solve the problem. There are exceptions, though. One subset of mechanical puzzle called an “impossible puzzle” requires no movement at all; instead, the player must figure out how the puzzle was built.

An online database of the collection lets users search by the puzzle’s date of creation, designer, maker, or classification. The oldest item is a 15th-century Khmer iron lock from Cambodia that contains trick locks and keys. But according to Indiana State Library, puzzles weren’t always created for their entertainment value. In the second century BCE, for example, Romano-Celtic puzzle padlocks were used strictly for security purposes. It wasn’t until the 19th century that the puzzle emerged as a fun pastime.

In a YouTube video uploaded by the Indiana Daily Student, the collection’s curator, Andrew Rhoda, tries his hand at the “Gear Cube Extreme,” which looks like a Rubik’s Cube on steroids. “The puzzle is complicated by the addition of gears that move at half-turns while the rest of the puzzle moves at quarter-turns,” Rhoda says in the video.

Unless a particular piece is being conserved, visitors are encouraged to grab a puzzle and start playing inside the library’s reading room. “Mechanical puzzles are really hard to understand if you see them behind glass,” Rhoda told the student news outlet in 2017. “You can sort of understand what is going on with a mechanical puzzle if you look at it behind glass and read an exhibit label. But to really understand the idea behind a puzzle, you have to handle it. You have to play with it. You have to try to solve it.”

Amazon's Under-the-Radar Coupon Page Features Deals on Home Goods, Electronics, and Groceries

Stock Catalog, Flickr // CC BY 2.0
Stock Catalog, Flickr // CC BY 2.0

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

Now that Prime Day is over, and with Black Friday and Cyber Monday still a few weeks away, online deals may seem harder to come by. And while it can be a hassle to scour the internet for promo codes, buy-one-get-one deals, and flash sales, Amazon actually has an extensive coupon page you might not know about that features deals to look through every day.

As pointed out by People, the coupon page breaks deals down by categories, like electronics, home & kitchen, and groceries (the coupons even work with SNAP benefits). Since most of the deals revolve around the essentials, it's easy to stock up on items like Cottonelle toilet paper, Tide Pods, Cascade dishwasher detergent, and a 50 pack of surgical masks whenever you're running low.

But the low prices don't just stop at necessities. If you’re looking for the best deal on headphones, all you have to do is go to the electronics coupon page and it will bring up a deal on these COWIN E7 PRO noise-canceling headphones, which are now $80, thanks to a $10 coupon you could have missed.

Alternatively, if you are looking for deals on specific brands, you can search for their coupons from the page. So if you've had your eye on the Homall S-Racer gaming chair, you’ll find there's currently a coupon that saves you 5 percent, thanks to a simple search.

To discover all the deals you have been missing out on, head over to the Amazon Coupons page.

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Philadelphia Is Now Home to a Yarn Vending Machine

Emani Outterbridge with her yarn vending machine in Philadelphia.
Emani Outterbridge with her yarn vending machine in Philadelphia.
Emani Outterbridge

When 24-year-old Emani Outterbridge was stuck at home with a broken foot this past spring, she got to thinking of new ways to bring her self-made designer yarn to DIYers around Philadelphia. What she landed on was the idea of a yarn-dispensing vending machine, which she floated to her followers on social media.

They responded enthusiastically, and after a whirlwind fundraising campaign, Outterbridge ordered three machines, ready to be stocked with rows of brightly colored skeins. Earlier this month, the first one made its society debut at Elements of Grooming, a Philadelphia barber shop owned by a friend of Outterbridge’s. Soon, curious customers flooded the shop, and Outterbridge (who was on a business trip to Miami at the time) received excited updates from the owner. With the first vending machine already a proven success, she’s now looking to place the remaining two at other local businesses before ordering more.

Outterbridge's vivid skeins in the vending machine.Emani Outterbridge

Outterbridge doesn’t just make designer yarn—she also crochets custom items for her fashion line under the name “Emani Milan.” She’s been crocheting since she was 12 years old, and launched her own online business at age 15 after finishing an entrepreneur course in high school. She’s even designed items for Cardi B, whom she credits with elevating her profile. Outterbridge tells Mental Floss that the best part about being a business owner is the freedom to be “completely committed to my own success.”

Part of that success comes from understanding the needs of her fellow crocheters (and knitters), which helped her come up with the innovative vending machines in the first place. “I was thinking … if I had something that’s accessible to me 24 hours, mid-project, if I need to stop and go get some yarn, a vending machine would be ideal,” she explains.

Since the first vending machine is currently housed inside the barber shop—and future ones will likely live indoors, too—Outterbridge is hoping to open her own brick-and-mortar store in order to give people round-the-clock access to yarn. “With the salons and the shops—they close," she says. “But if I had my own store, I can have it open 24/7, so that’s what I’m pushing for.”

A future crocheter checks out the goods.Emani Outterbridge

In the meantime, she’ll continue offering her vibrant yarn skeins and garments through her website. Though you might assume a career crocheter would look forward to making cozy sweaters and scarves for chilly weather, Outterbridge actually prefers the summer months, which allow for more “creative range”—items like swimsuits, coverups, skirts, and rompers.

While you’re waiting for a yarn vending machine to land in your neighborhood, you can follow Outterbridge on Instagram and check out her products here.