We just learned that. You’d think we’d have known. Now we do. They’re sort of like round dreidels, with a hollowed-out middle around the stem, which causes them to turn themselves upside down while they’re spinning. Great lesson in center-of-mass instruction for physics teachers. Includes an explanatory booklet with activities and discussion topics. You’ll get (3) wooden tops at 7/8”, 1-1/4” and 1-1/2” dia.

If the question is whether to tie a bunch of these giant latex professional weather balloons to a lawn chair, the answer is no. (The balloon bursts at about 82,000 feet anyway.) This is a true high altitude weather balloon, with plenty of fun, nonfatal uses. The cream-colored latex balloon is approx 40" dia when flaccid, you should pardon the expression, but has an 8-foot dia when inflated. The neck is 9" long x 1" dia. Scientists and meteorologists launch balloons to measure atmospheric conditions like wind speed and air pressure for weather forecasting, but clever inventors, teachers and the imaginative filmmaker are warned to launch the balloon carefully. The synthetic rubber material is delicate and not made to survive brushes with pavement, pine branches, or clumsy physics students. Red not available and only available in egg shell/cream color only.

They might as well learn something while they're trying to outlast you on eating those lima beans. Set the table with educational placemats and they'll be at least a touch smarter after dinner, even if their vegetable intake is low. These laminated, 12" x 17-3/8" mats have full-color fronts, black-and-white backs. Choose the United States Map, Stars & Constellations, the Periodic Table of Elements or The Metric System.

Nice little teaching magnet set for the primary grade classroom has (6) magnets in star, two-bar, horseshoe and ring shapes, all plastic coated in silver and red to mark the poles. Range in size from 1” to 3”, and include a few paper clips and small nails for demo purposes.

Begin their microscopic education here, with this 40-640X student microscope from Levenhuk®. Featuring an adjustable eyepiece, variable white LED illuminator, and adjustable iris. Comes with a cover; (5) blank and (5) prepared slides; pipette; brine shrimp, yeast, sea salt and glue samples; forceps; a microtome; 58-page user guide; and a 23-page manual. Includes (2) “AA” batteries and a lifetime warranty through the manufacturer.

Classroom and Science Fair alert: Now you can order an 8-pack of metals and metal alloys for demonstration purposes. Each pack of 1" dia x 1/32" thick discs includes aluminum, bronze, brass, copper, n/silver (w/nickel), m/steel (mild: low carbon), stainless steel, and zinc. Composition of each is stamped on one side of the discs.

The next best thing to lightning bolts! 200,000 volts of electrostatic energy created by our Van de Graaff generator. Measures 6-1/2” diameter by 15” tall, includes a spare belt and a set of instructions detailing lots of fun experiments. For grade 6 and up. This is not a toy and should be used under adult supervision. A great tool for teaching about electricity. For your convenience, we now have Lightning Belts: replacement belts to drive that overworked generator. Operates on Standard 120 VAC with the included 3' cord.

The human body is a puzzle, really. Get a head-start on anatomy class with one of these anatomically correct breakaway models in authentically colored plastic with detailed cross-sections. Pick the 2" tall, 7-piece eyeball; the 3-1/2" tall, 6-piece human heart; or the 3-3/8" tall, 6-piece rubber and plastic human head/skull/brain. All stand on 3" square bases.

…when you crank up this 13-1/4" tall, hand-cranked Wimshurst generator. They were the toast of the 19th Century, and remained the hottest thing around, electrostatically speaking, until Bobby Van de Graaf came along. This one works like a top, zapping sparks to a fare-thee-well with very little cranking. It's mighty pretty too, in acrylic, white and silver, and will dress up a dull physics or electronics lab.

An easy way to light up the kids' eyes! Teach them to wire a simple circuit with our basic components.

• The knife switches are mounted on a plastic bases.
• The miniature plastic socket holds a standard flashlight bulb with a 14 mm dia screw base.
• We pack 6 volt and 3 volt round bulbs, or 1.5 volt bell-shaped bulbs, (5) to a package.(Bulbs are rated slightly higher to prevent them from burning out.)
• Hook up the black plastic and metal 2" x 4-1/4" telegraph key with brass contacts and (2) terminal posts with nuts.
• Our blue-plastic holder for (1) "D" battery has a small tab at each end to hook a lead to, and a 1/8" square mounting hole at each corner.
• You add the mounting surface and the know-how.
• Actual bulb voltage listed in parenthesis.