You can start with our single aluminum tuning fork, 2-tined and 7-1/2" long. It vibrates at 256 hz, and is labeled "C". Or you can order the set that has (8) forks and a mallet with a rubber-tipped plastic head. The forks are labeled low-C to high-C and come in a fitted, latched wooden box. Unfortunately, C.J., who has perfect pitch, tells us that his pitch is more perfect than most of the tuning forks. He also says you can file the tips, tuning them to an electronic keyboard until they're perfect - and we think there's a certain cachet to telling people you tuned the forks yourself. But they are perfect, if you're using them for things like teaching principles of sound or driving the chihuahua crazy.

Physics project alert! This robust puppy of a magnet has dual 6V coils and stands 4" high x 3-1/4" wide, not counting the side terminals. Each coil draws 2.4A at 6VDC, and is conservatively rated for 40 Newtons (approx 9 lbs) at that voltage. Can be wired in either parallel or series, and comes with a mounting hook. Works great with a 6-volt lantern battery.

…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.

Ferrite ceramic magnets can be quite powerful and have excellent resistance to demagnetization. These rectangular ones are no exception. Add the power of surplus and we'll give you a bunch of these mighty-mites at an uber-bargain price. Measures 1-7/8" x 7/8" x 3/8" thick with a 3-lb pull. Perfect for mounting even big pix on the fridge.

Good quality precision compass from Helix®. Measures 4-1/4" long and opens to a maximum of 2-1/8". Includes (3) spare 2mm leads and a spare locking wheel for leads on account of people losing them all the time.

So the poster is really brand new. The animals on it are (1) to (190) million years old, and if that doesn't qualify as pre-history, may we stumble over a glyptodon in the dark. Invicta Plastics Ltd. of Leicester, England, printed this 23" x 16-1/2" poster with a colorful diorama to promote their authentic scale models of prehistoric animals. A time line across the bottom lists dates and data for a dozen of them, from the plesiosaur to the woolly mammoth, and compares their sizes to that of a pair of five-year-old children. Post it on the fridge to spark supper discussions, or in the classroom as a source of extra-credit questions for science quizzes.

This 96pp, full-color, heavily illustrated book, "The Usborne Internet-Linked Book of Astronomy & Space," is written with a quick-link to the publisher's website, where there are updated links to internet sites that correspond to specific pages of the text. Sections include the solar system, stars, constellations, telescopes, photography and a plethora of astronomical facts and lists. From Usborne Publishing.

Surprise your parents with a little science at home. “Science Surprises” is a 192-page paperback in its third edition with over 100 experiments that can be done using common household goodies. OK, a couple of things might require a trip to the hardware store, but still.  The science ranges from the Bernoulli principle and Stroop effect to making your own perfume and cold cream. (And remember what Shaw said: “Science never solves a problem without creating ten more,” so that makes a thousand experiments.)

Genuine, original, accept-no-substitutes brand-name Sharpie®s for when you really mean it and want a permanent marker. You pick the fine point red, blue or black, or the blue with a 3/16” bullet tip.

Why do your feet look like they are attached at a different angle when you're standing in water at the beach? Teach the children with this plastic water prism. Also make rainbows. Measures 8-1/4" x 2" x 1" with 3/8" squares across the surface to measure refraction.

That's what you get with this tesla coil!! Brand new, commercial item, great for classroom demonstrations and experiments. The 50,000 volt capacity generator radiates high frequency energy through space... enough to light fluorescent tubes two feet away. It uses 115 VAC (60 Hz) with an electro-magnetically operated interrupter buzzer, high voltage capacitors, inductive coil transformer, and a monopolar high frequency transformer generator to do the trick. 11" high, with a 6" sq. x 2" high protective housing for the generator. Includes accessories and instruction booklet with 19 experiments. Pretty amazing. But please, this is not a toy and should be used only under adult supervision.

Our each is a set of (8) sturdy plain white heart-shaped jigsaw puzzles, along with envelopes to mail the pieces in. You paint or draw on the blanks (think Valentines, invitations, or general lovey stuff), snap them apart and send the pieces to someone you really like. Hearts are approx 5-1/2” across on 6” x 8” cardboards.

You can write on duct tape, but try to change your mind later and see what happens. We recommend these 12-foot x 1-7/8” wide rolls of dark gray chalkboard tape, which you can write on with, you guessed it, chalk; or the 12-foot rolls of the more modern dry-erase tape, which we’ll pick for you in either white or day-glo orange.

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.

Ceramic magnets, 15/16" dia x 3/16" thick. One side has a 5/16" sq that goes through to a steel plate is octagonal, 9/16" across with a 3/16" dia hole in the center. The plate allows flexible mounting of the 3/4 lb lift magnet. The other interesting feature is that the ceramic appears to have many poles around the rim, (4 ea N and S). This may be a focussing effect of the insert, though.

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.

And you need to know how to stay alive on them. We recommend that you choose one of these books to help with that: the U.S. Army 1976 training circular Military Mountaineering, a 139-page paperback guide to survival and combat on glaciers, mountains and alpine paths; or the Department of the Army Map Reading and Land Navigation, a 113-page field manual originally published in 1993.

Beats us, frankly, but this black plastic cover, 1-3/4” x 1-1/2” x 1/4” (not unlike a tiny toilet seat cover) is hiding a really nice 1” dia x 1/8” (think: quarter size) plated neodymium magnet, with at least a 5-lb pull, inside. The mystery is that the cover won’t open unless you break it. The magnet grabs fine in the case or out of it. Tap it on its side with a hammer to crack open the case and reveal nothing but magnet.