Musician, artist, and "edutainer" Tom Kaufmann makes unique instruments called lithophones, which are similar to xylophones, but created from various stones. Here's how Kaufmann describes them: Another happy coincidence led me to my current fascination with constructing lithophones. I was tossing around some scrap pieces of granite countertop that I’d gotten for one of my Upright Furniture projects, and as one of the chunks landed, it rang as clear as a bell. I’d been looking for stone... READ ON

Julia Suits has assembled a book filled with ads for real prank machines used in fraternal lodges in the early part of the 20th century, complete with an introduction by David Copperfield. This volume is extremely appropriate for readers of mental_floss, as it's full of trivia on weird inventions, the history of pranks, and a very special form of Americana. The book is bizarre and hilariously perverse, packed with clippings from catalogs sent to the high muckety-mucks at the Modern Woodmen of America,... READ ON

Last year I pointed to some machines that turn themselves off -- these are called "Ultimate Machines," and generally take the form of a box with a switch. You flip the switch, the box activates and flips the switch back, turning itself off. That's all the machine does -- return it its steady state. But today, Jason Kottke (via David Gallagher) brings us what might be the Ultimate Ultimate Machine -- stick around to see what happens around the one-minute mark: More examples: This Machine Turns... READ ON

I'm not colorblind, I'm just "green-weak." At least that's what I tell everyone. I wrote about my color vision problems way back in 2007, explaining my Deuteranomaly, a condition affecting roughly 5 out of every 100 men. There are other forms of colorblindness, but this one is mine. In short, it means that things that other people see as green, I don't -- I see them as brown, or beige, or some other neutral tone. Over the weekend I bought a bunch of glass bottles to put hard cider in. I did not know... READ ON