xix Pyrometer or Thermometer 249 



reputation abroad as he had at home. In Sweden 

 his papers were voluminously reprinted. The Eoyal 

 Academy of Sciences at Upsala (the Swedish University 

 near Stockholm) not only possess the Transactions of 

 Josiah Wedgwood, with a copious table of contents, 

 in five volumes; but also his Chemical Collections, 

 consisting of many valuable articles and memoranda on 

 assaying, metallurgy, dyeing, painting on glass, glazing 

 for porcelain earths, cements, colouring matter, fur- 

 naces, and so on, with tables of specific gravities, also 

 in five volumes. Both of these series (according to the 

 Catalogue in the British Museum) have been translated 

 from the Swedish and German, with some pieces from 

 original sources, by Dr. W. Lewis, author of Experi- 

 mental History of the Materia Medica. These docu- 

 ments are very neatly written, and illustrated with 

 drawings. Ten vols. Eoyal Svo. 1 



Considerable progress has inevitably been made in 

 the measuring of intense heat. A new method was 

 invented by Mr. Gurney, which he employed in his 

 chemical lectures, for ascertaining the relative expan- 

 sibility of the various metals that can be drawn into 

 wire. But the most important improvement in the 

 pyrometer was that invented by Professor Daniell in 

 1821, which has, for the most part, superseded all 

 others ; though Wedgwood's use of clay, in the form of 



1 The Wedgwood MSS. collection in the British Museum. The 

 Press marks are 



Additional MSS. 28,309-313. 

 Do. do. 28,314-318. 



