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NATURE OF THE PYROMETER.

be measured, till it shall have been completely penetrated by it.It is then removed and applied to the gauge. The difference be-tween its former and its present dimensions, will show, howmuch it has shrunk ; and will consequently indicate, to whatdegree the intensity of the heat to which it was exposed,amounted.

High temperatures can thus be ascertained with accuracy.Each degree of Wedgwood's pyrometer is equal to 130° ofFahrenheit’s.