Jones, Apparatus used by Dalton. 



Plate VI. 



1. A maximum and minimum alcohol thermometer on wooden 



scale (one bulb broken), made by H. H. Watson, Bolton. 



2. A maximum and minimum thermometer used by Dalton and 



stamped with maker's name, J. Ronchetti, 29, Balloon 

 Street, Manchester. 



3. Mercury thermometer attached to strip of wood stamped 



with the date 1823, apparently made and graduated by 

 Dalton. 



4. Mercury thermometer with file marked graduations on the 



glass stem. 



5. Mercury thermometer with long stem and wooden scale. 



6. Glass tube used by Dalton for measuring the tension of 



carbon disulphide vapour. There is a paper scale 

 attached on which in Dalton's handwriting may be seen 

 "Sulphuret. carb." There is a cork at the upper end 

 apparently used for supporting this portion of the tube in 

 a water bath. 



7. Bent glass tube. 



8. Small glass tube bent at lower end and with paper scale 



attached. 



9. Mercury thermometer attached to strip of wood made and 



graduated by Dalton and stamped J.D. 1823. The freezing 

 point of this instrument was tested in 1876 by Mr. 

 Baxendell, who found that it had not altered since the 

 original graduation. I have re-tested the freezing point 

 (June, 1904) and find it about ^ of a degree Fahrenheit 

 below the mark on the stem. 



