$11.99 $14.99
Filled with vibrant red sand this is a heavy, substantial piece. The hourglass is encased in acrylic, protecting it from breaking, making it an ideal gift for children (or children...
$24.99
The Newton gravity glass is an awesome desk-topper and a question-generating educational tool. When the cylinder is flipped, the sand within the hourglass moves down while the hourglass itself floats...