26 Gee, Dalton' s Lectures and Lecture Illustrations. 



readily be deduced that the value T on the new scale 

 will be given by the formula : — 



Jf + 40 - J' 



T = 



/ VF + 40- sfj2 \ 



, j=- x 180J + 32. 



\ V252 — V72 / 



where F is the temperature on the Fahrenheit scale. 

 Mr. Arthur Adamson finds that this formula agrees 

 with the numbers calculated by Dalton. 



We now know that the scale proposed by Dalton 

 is untenable, and in the Appendix of the 1827 edition 

 of Part I., Vol. 1 1, of the " New System " he admits that 

 it is so in the light of the researches of Dulong and Petit 

 on the expansion of mercury. 



Sheet 23. 



Eleven thermometers are shown each 17 inches long, 

 the spherical bulbs are blackened and so also is the 

 lower part of the stems to a common level, The 

 graduations on the thermometers are : — 



No. 1. Right side t, 2, 3, 4, 5, 6, 7 

 Left side r, 2 2 } y, 4-, 5", 6' 2 , f 



,, 2. 



Earthenware 



(0 



in 10 spc 



ices tror 



Q 36 



to 



106 



» 3- 



Earthenware 



(2) 



115; ? 



) 55 



40 



to 



no 



,i 4- 



Glass ... 





5J )1 5 



)) 



44 



to 



111J 



» 5- 



Iron 



... 



55 5» > 



1 55 



42* 



to 



Il2 i 



., 6. 



Tinned Iron 





5'55 5 



)» 



42j 



to 



\12\ 



m 7- 



Copper 





5> )5 5 



55 



45i 



to 



IX 5i 



„ 8. 



Brass ... 





J5 5) 51 



1 5 



46 



to 



116 



>, 9- 



Pewter ... 





5)55 5 



55 



46 



to 



116 



„ 10. 



Lead 





5) 5> 5 



5> 



49i 



to 



"9i 



,, 1 1. 



No graduations. 













Sheet 24. 



(19" X 33"-) This is marked by Dalton : — " Water 

 therm." On the left-hand of the sheet two thermometers 



