Here's a handy carrying case for your movie reels. Made from 6" self-locking stovepipe, it stands 17 ½" high and accommodates 24 ordinary 200-foot reels.
After compressing the pipe until it just suited the 5 ¼" diameter of the reels, I cut it lengthwise into halves. Then I hinged the parts together, drilling the metal and using rivets to attach the hinges. On the other joint, I installed two suitcase catches, locating these to take care of the overlap.
This multiple tape recorder removes the last obstacle to commercial recordings on magnetic tape -- the mass production of duplicate tapes. It makes eight duplicates at once at three times normal speed. It can also record two sound tracks on the same tape at the same time. Thus the machine can turn out eight hour-long recordings in 10 minutes, or 48 an hour.
You shouldn't fall asleep at the wheel with this chin jabber on the job. Worn around the neck, it holds a sharp prong under the driver's chin. If his head nods, the point quickly awakens him. Invented by K. H. Liman, of Rye, N.Y., it has a rubber knob below the tip to prevent serious injury.
Just wanted to remind everyone that there's only one more weekend left to work on your re-purposed tech projects for our contest over at Instructables, so get cracking! April 1 is the deadline, meaning there's still time to grab some e-junk and turn it into something new and exciting. Head on over to the PopSci group to see what's been submitted to date—we're not going to single out any of our favorites just yet (must preserve impartiality!) but let's just say there have been some pretty amazing entries so far; some you might have even seen being picked up on blogs already. Check 'em out here. —John Mahoney
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.