Edward Mogg (worked 1805-1848) was a cartographer by trade but made a celestial sphere (above) It was similar to Mrs Johnstone's dissected terrestrial globe of 1812 (Image 1). Mrs Johnstone's and Mogg's 'spheres' were made of interlocking cardboard plates, rather than being 3-D globes, and both were accompanied by a booklet. Mogg's 12 cardboard plates and his printed booklet were sold together in a firm paper slipcase, with the image on the front of the slipcase challenging young users to assemble a globe from the pieces enclosed (Image 2). The sphere was priced at 10 shillings, about the same as educational books and miniature instruments of the period.
Learning by doing
Towards the end of the 18th century educational theorists increasingly insisted that children should be physically active while they learnt. Recommendations ranged from providing regular breaks to run around and exercise the whole body, to using novel educational devices that allowed children to use their hands while they used their minds. Mogg's celestial sphere was one such device. Since the pieces could not all be seen clearly while the plates were fitted together, learning from the globe required that children continually put together and took apart the sphere as they read through the book; playing with the pieces was crucial to the learning process.