there were hand-blown glass radiometers , infrared cameras , neutral buoyancy frisbees , dinosaur chia-pets , binary wristwatches , mexican jumping beans , compasses , sextants , pedometers , otoscopes , microscopes , kaleidoscopes , oscilloscopes , gyroscopes , periscopes , 3d mirascopes , laser pointers , the worlds smallest motor , a game called identify that mineral ! , pin-depression pads of various sizes , potato clocks , miniature wave pools , those metal balls that clack against each other , magnet powered kinetic art sculptures , metal detectors , analog geiger counters , genuine moon rocks , petrified dinosaur dung , water pressure rockets , bigger bubble builders , rube goldberg toast maker kits , frequency finders , custom kite kits , micro helicopters , magnetically crushed quarters , air cannons , voice changers , mini echo chambers , ant farms , bonsai potato kits , homemade hair-gel kits , model dinosaur bones made of balsa wood , anatomical models of the brain , ear , heart and lung , sugar crystal farms , young architect kits , origami architecture kits , cassettes of whale vocalizations , optical illusion posters , spiral spinning tops , invisible ink pens , black lights , snap circuit boards , magnetic silly putty , light bender kits , laser pointers , erupting volcano models , brew your own root beer guides , make your own bubblegum kits , dead tarantulas and scorpions encased in clear resin , lava lamps , true mirrors , bacteria farms , jacobs ladders , infrared cameras , pixel cameras , and all sorts of puzzles and games and globes and maps .