Around 1782 potter Josiah Wedgwood invented a different type of pyrometer (or rather a pyrometric device) to measure the temperature in his kilns, which first compared the color of clay fired at known temperatures, but was eventually upgraded to measuring the shrinkage of pieces of clay, which depended on kiln temperature (see Wedgwood scale for details). Later examples used the expansion of a metal bar.
Around 1782 potter Josiah Wedgwo,od invented a different type of pyromet!er (or rather a? pyrometric device) to measure the temperature in his kilns, which first compared the color of clay fired at known temperatures, but was eventually upgraded to measuring the shrinkage of pieces of clay, which de:pended on kiln temperature (see Wedgwood scale for details). Later examples used the expansion of a metal bar.