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Tefe Equipment of a High Temperature Measurement 

 Laboratory. 



By G. A. Shook. 



ilSASUKEiMENT OF HIGH TEMPERATURES. 



The first attempt to measure temperatures with any accuracy seems to 

 be due to the celebrated potter, Wedgewood, although he was not the first 

 by any means to recognize the importance of temperature estimation and 

 temperature control in kilns in order to reproduce a given effect. In the 

 time of the Eomans the working of iron had undoubtedly reached an ad- 

 vanced stage, but their methods and knowledge of the metallux'gy of iron 

 were entirely empirical. In the eighth century a writer, in outlining a 

 method for obtaining high temperatures, called attention to the most diffi- 

 cult part of the problem, namely, that "fire is not a thing which can be 

 measured." Even within recent years the temperature of a steel kiln was 

 not known within 500 degrees C. and the values given for the temperature 

 of the sun ranged from 1,500 to l,000,riOO degrees C. Today, however, with 

 our advanced methods of radiation pyrometry, the student of physics can 

 measure the temperature of the sun, the highest known temperature, with 

 as much ease and accuracy as he can determine the specific heat of a piece 

 of lead. 



It has been known for several years that numerous industrial processes, 

 carried out at high temperatures, require a temperature control of 20 de- 

 grees C. Mv. C. E. Foster\ in speaking of the successful production of fin- 

 ished castings, remarked that there are four main factors to be considered: 



1 — Comijosition of the material melted. 



2 — Atmosphere and surroundings. 



3 — Tempera ture. 



4 — Time. 

 The fii-st two of these are taken care of by the chemist, but the third 

 and fourth must be controlled by tlie man trained in pyrometry. It requires 

 but a casual glance through the trade journals to convince one that the 



1 The Foundry, May, ]009. 



