A pair of half hemispheres with vacuum tap and removable iron handles, diam. 8-10cm. From the 17th century on scientists examined ‘air’ and asked themselves whether a vacuum existed. In germany otto von guuericke designed two hemispheres that fitted exactly together and once the air was drawn out, could not even be parted by horsetension. He performed his tests in the city of magdeburg and since that time these spheres are called “magdeburger hemispheres”.