REVERSING THERMOMETERS 



45 



in spite of numerous experiments, it has so far 

 proved impossible to remove it completely. Negretti 



s70^ 



Fig. 7. — Six Maxi- Fig. 8. — Frame of Fig. 9. — Reversing 

 mum and Minimum Reversing Ther- Thermometer. 



Thermometer. 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 



