REVERSING THERMOMETERS 



45 



in spite of numerous experiments, it has so far 

 proved impossible to remove it completely. Negretti 



FIG. g. REVERSING 

 THERMOMETER. 



FIG. 7. Six MAXI- FIG. 8. FRAME OF 

 MUM AND MINIMUM REVERSING THER- 

 THKRMOMETER. MOMETER. 



(Figs. 8 and 9 by permission of Messrs. Negretti and Zambra.) 



and Zambra trust entirely to the shape and size of the 

 constriction, while Richter provides an additional 



