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.

Little-bitty horseshoe magnet, for traditionalists. Just 1-1/4" across x 1" x 5/16" thick. Red-painted Alnico, with approx 2.9 lbs of pull (ignore the 2 lb on the label) it includes a little steel keeper for when it's not sticking to a tiny horse's foot.

You win some, you lose some? No need to keep switching pens when you have this two-headed ball point pen with a black cartridge at one end and a red one at the other. Perfect for those hand-held profit and loss statements.

Same here. Try the Ferrofluid Magnetic Display, a little sealed bottle with virtually fluid nano-particles of ferrous metal suspended in liquid. You’ll get (4) powerful 1/2” dia x 3/16” neodymium disc magnets, (2) of them attached to chess-pawnish holders. Move the magnets in assorted combinations around the bottle for fascinating effects. Sort of the marriage of science with desk toys, but students can’t spill these particles all over the place.

Sounds like a Portuguese percussion album, but it’s just an alnico bar magnet in a mount that lets it rotate freely to demonstrate the three-dimensional magnetic field. Ideal for experiments about forces between magnetic poles, fields around wire and coils, and the properties of fields produced by electric currents. Also handy as part of your ghost-hunting gear.

The Ultimate Guide to Your Microscope, by Shar Levine and Leslie Johnstone is a 144-page softcover book covering lenses, lighting, slide-making and what to look for in various samples. Heavily illustrated with color photography. Don't take the scope out of its box without this book.

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.

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.

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.

This 10-piece set of 1" cubes is made to test density in the classroom, and by all means you should do that. Otherwise, how will the children ever understand density? But we like to just play with the cubes, to set them on a desk, or stack them, or line them up, or make shapes out of them, or just pick them up and marvel at their weight differences. You get perfect cubes of aluminum, steel, brass, copper, acrylic, oak, nylon, pine, poplar and PVC.

Or want to teach kiddies to write like Dickens or draw like Michalengelo? Start with blank, staple-bound 28-page paperbacks with bright white, 80-lb paper stock pages and card-stock blank covers. You pick: the 7” x 8-1/2” books or the 8-1/2” x 11” book, both with un-ruled pages because when you're young, staying between the lines isn't the thing to do.

These Kooties™ are impish little trademarked critters, and in this case they’re on the hardboard covers of these mini-notebooks. Measure 3-1/4” square, top-spiral bound with (71) sheets in each with little Kooties and Kuotes in the Korners. We’ll pick from the (7) assorted Kooties™ on the covers, but they’re all kute. Kinda.

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 magnetic sheet isn't large enough to make a magnetic bed, but it's just right for making a bulletin board, hanging on to a rounded surface, or clinging to a car door with its glossy magnetic side. It's a flexible, very dark brown rubber-like material, easily cut with scissors. A 2-ft piece is cut for you from the 2-ft wide x .011" thick material.

These mighty nice little ceramic disc magnets measure 18mm dia x 6.5mm thick, which in America, Burma and Liberia is 23/32" x 1/4", and for those of us still math-impaired, roughly a stack of (5) dimes. They have a 1/4-lb pull. No crafter should be without an enormous supply of these. Also note the physics-class-friendly bulk price.

Wonderful little book jammed with elaborate colored drawings that tells the beginner a little about everything to do with a microscope. And all in a mere 48 pages! From data on the history and types of microscopes, to introductions and samples and how to prepare them, (from tissues and insects to crystals) to ideas for experiments and lists of simple equipment needs, and how to build them at home, this book is a veritable cornucopia of information. If you are thinking of getting a microscope, we strongly recommend "The World of the Microscope" as a great stimulus for the novice user. It won't answer heavy duty scientific questions. But it will keep the beginner busy, challenged and entertained for days and weeks! By Chris Oxlade and Corrine Stockley. Paperback, 7-3/4" x 9-3/4". One of the Usborne science and experiments series of books.

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.

Geometry teacher alert. These 6" plastic protractors have a 6" x 1/16" ruler on the bottom, and measure 0-180 degrees in one-degree increments on the outer arc and 10-170 degrees and 10cm ruler on the inner side. You’ll get a quartet of them in assorted colors, including clear and translucent red and blue.