THERMOMETER AND PYROMETER. 



of the results obtained in 1782, by La- 

 voisier and Laplace, lately recovered 

 by Biot. Each substance at 32 F.= 

 1.00000000. 



There is one precaution in graduating 

 thermometers, which will render any 

 irregularities of little consequence ; that 

 is, in forming the scale, not to rest satis- 

 fied with only two fixed points, and 



equally dividing the intervening space ; 

 but to obtain intermediate points by 

 means of mixtures, or by comparison 

 with a standard instrument so formed ; 

 and by the shortness of the intervals 

 adapting the scale to inequalities in the 

 bore of the tube, or to the less impor- 

 tant irregularities just now considered. 



