40 & Mr. Wedgwood’s additional Qbfervaiiom, &c. 
not be lefs fuccefsful in fupplying what may frill be deficient* 
and in ascertaining, by the coniruBion of argillaceous matter , 
the meafu remen ts and effects of the various degrees through 
the immenfe extent of luminous fire, than they have been 
with refpe£t to the limited and narrow compafs of low heat, 
which is meafurable by the expanfon of fiuids. 
