
About 40-50 highly polished stones, all shiny, translucent, or brightly colored, ranging from 3/4" long to 1/8" long. Great for mosaics, jewelry, or aquariums.
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90006 TUMBLED GEMSTONES |
Nice plastic figures on cotton thread. We have orange pumpkins, white ghosts, and black witches. Each figure is about 2" x 1", and each garland stretches to 9 feet. We'll send (1) of each type per order. Great party fixins!
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29075 HALLOWEEN GARLANDS |
Bunsen-Dibdin photometer box for mounting on a meter stick. Normally used in a physics lab together with light sources that also mount on the stick, you could rig up your own lights and have a complete lab experiment set. Cenco #86445, it is often sold as a replacement item. No instructions.
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30287 PHOTOMETER BOX |
WARNING: CHOKING HAZARD-Small Parts. Not for children under 3 yrs.
Plastic disc, 2-1/4" dia with a diffraction grating face. Place the disc in the sunlight, and it will reflect a myriad of rainbow splashes on a wall, ceiling, screen etc. Neat!
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88884 RAINBOW BOUNCER |
WARNING: CHOKING HAZARD-Small Parts. Not for children under 3 yrs.
The Cool Blue Light Experiment Kit uses copper sulfate, perborate and luminol to produce light from the energy released in a chemical reaction. The instructions recommend this kit for experimenters nine years old and up, with adult supervision. Some experiments call for the addition of household chemicals like chlorine bleach, hydrogen peroxide or sugar.
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90154 COOL BLUE LIGHT KIT |
Rarely have we seen such boring teaching aids. Aides yes, but not aids. 4" Sq. cards. The red ones have lines dividing them into 10ths, with from one to nine of the lined off bars shaded. The green ones have lines in both directions, hence are divided into 100ths. From 5 to 95 of the resulting squares are shaded, always in multiples of 5. On the yellow, the 100 squares of the green cards are each sub divided into 10 giving 1000 (yawn) parts to the whole. From 25 to 975 parts are shaded, in multiples of 25. (Snzz) If this how to teach decimals, its no wonder the kids don't learn. Turn the cards over and use the blank sides for craft projects. You get a total of (76) cards, two of each possible red, one of each possible green and yellow. The above should allow you to compute how many of each color you get.
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23299 DECIMAL CARDS |
WARNING: CHOKING HAZARD-Small Parts. Not for children under 3 yrs.
2" flywheel in well made metal frame. The trick is the same as it has been for 100 years. Wind the string through the spindle, pull it firmly to set the flywheel spinning, and perform effortless balancing magic on pencil tips, string tightropes, and the like. We tend to forget that bicycles and aircraft navigation both rely heavily on gyroscopic principles. It's never too early to tell the kids. Besides, it's fun.
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3804 TEDCO® METAL GYROSCOPE |
Simple, yet clever 1" dia. by 3" long plastic device to demonstrate the vortex effect of a tornado. Partially fill with water one of the two half-gallon size plastic soda bottles which you supply. Screw the bottles into opposite ends of the tube which we supply. Tip so the full bottle is on top and give it a circular starting whirl. Presto! You have a vortex. Call it a tornado if you're a meteorologist, a Charybdis if you're a classicist, or a whirlpool if you're into oceanography. Lots of fun and a fine opportunity to attempt to explain the effects of the earth's rotation on water draining out of a bathtub. The phenomena are related we're told, but good luck!!
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6667 TORNADO TUBE |
Optical grade unsilvered glass prism from Uncle's WWII tank periscopes. This one is 2-1/8" on the hypotenuse, 5-3/4" long, and 1-1/2" on each leg. They may come with small non-interfering chips or surface scratches. Great for classroom experiments or for art projects. These are a true surplus find and they will not last forever so get yours today!
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3538 MINI-MONSTER PRISM |
Al Luebbers, our founder, collected glass. Not glass like you'd find on a knick-knack shelf, but optical glass. Lenses, prisms, reticles and filters, for example. Focus on the filters. Many of his filters came out of military surplus, and this is for-real stuff. We mean many are solid dyed optical glass, ground and polished to flatness standards that were probably excessive. Others are from the old days in photographic optics, and their standards were even tighter than your militaristic Uncle's. We've found that photographers, artists, and optical designers still have an occasional need for good glass filters, so we're making a list of some goodies. As always, don't be timid about calling for quotes on quantities. If we have 'em, we'll sell 'em. Just don't sell them back. Please!
| DIAM.or SIZE (mm) | CENTER THICK (mm) | |||
|---|---|---|---|---|
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3477 FILTER, AMBER | 26 | 1.5 | |
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3492 FILTER, AMBER | 30 | 2.3 | |
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3480 FILTER, NEUTRAL | 26 | 1.5 | |
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3490 FILTER, NEUTRAL | 30 | 2.3 | |
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3510 FILTER, NEUTRAL | 50x54 | 3.1 | |
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3512 FILTER, NEUTRAL | 67x70 | 4.1 | |
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3458 FILTER, RED | 6 | 1.4 | |
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3464 FILTER, TYPE A | 9 | 1.8 | |
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3470 FILTER, YELLOW | 18x18 | 1.6 |
We've got (2) great grid-posters for the classroom or the lab. The 18" x 24" posters have 1/2" squares, 33 x 27, with headers on the x and y axis. The all-around borders have outer-space images or dinosaurs. Why not get both?
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32302P36 DINOSAUR GRID POSTER CLASSROOM PACK | |
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32302P2 DINOSAUR GRID-POSTER | |
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32301P36 SPACE GRID POSTER CLASSROOM PACK | |
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32301P2 SPACE GRID-POSTER |
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