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.

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.

Kitchen conversions are easy with this 3" x 4" deluxe American Science & Surplus fridge magnet that lists everything from a tablespoon to a cup with the equivalent in ounces, tablespoons, teaspoons, milliliters and fractions of a cup. If your kids already have fridges of their own, you can share the extra magnets with them - unless they were the only kids on the block who knew how many ounces were in a cup. Kitchen Fun.

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.

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.

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.

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.

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.

No, no, no--nobody likes to see a pooch penned up. These are ball-point pens inside plastic dogs. They’re long, with spots, like dachshund-dalmatian crosses, but in pink, blue, white or yellow. We’ll pick (2) different colors for you. Pull the tail on the 4-1/2” long dogs, expose the ball-point, and bring a little canine whimsy to your memo, love poem, grocery list or resignation letter.

Call them the Founding Replicas and display them in the classroom, whether at home or in school. The U.S. Constitution is 18-1/2" x 12-1/2" and the Bill of Rights is 15-5/8" x 13-5/8", both on realistic "antiqued vellum." These are nice replicas, but much reduced in size, the Constitution in particular will require magnification for reading. Our each includes both documents.

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 or blue, or the blue with a 3/16” bullet tip.

Our grandmother used to tell us that all the time, and we might have learned something while we were out there if she’d given us The Kid’s Guide to Exploring Nature, this 120-page paperback from the Brooklyn Botanic Garden. Chock full of information, photos and illustrations for exploring nature in both the city (includes pigeon info!) and the countryside, and in all four seasons. They might stay out of your hair until supper.

White chalk is fine but imagine the possibilities of a full palette of colors. Looks nice, right? Our box is (16) pieces of washable chalk at 3-1/8” long x 3/8” dia, and you’ll get (3) boxes, each with (2) pieces of green, purple, yellow, pink, hotter pink, blue, orange and white, which is a color too.

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.

If you make cool stuff, people will pass it on to your children’s children’s children and you won’t spend eternity as just an old picture on a lost thumb drive. We suggest: Making Inventive Wooden Toys, a 184-page paperback with plans for (33) toys, many of them ballistic, out of scrap wood and easily found hardware; or Making Poor Man’s Guitars, a 176-page paperback with detailed instructions for building string instruments out of cigar boxes, frying pans, tin cans, mailboxes and washtubs, with a beer-can microphone thrown in.

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.

These (2) reproduction maps are printed on "antiqued vellum" and are both approx 15-3/4" x 14". They show, respectively, the locations of Civil War battles and the principal events in the Revolutionary War, along with chronologies at the bottom. Lots of info packed into a small space, but the kids will read them easily. You might want some glasses. Includes both maps.