Manchester Memoirs, Vol. lix. (191 5), No. 1£. 29 



5. Salt Water ... ' ^V = 500. 



6. Sul. and Mur. Acid ... ~ = 600. 



7. Ether, oil Turp tV = 7°°- 



8. Oils T ^ = 800. 



9. Alcohol, Nit. Aci. ... \ =1100. 

 10. Air f =3750. 



The above is printed by hand on the chart, and 

 the right-hand numbers, after dividing by 100, are used 

 to show graphically the expansion. Thus air is rep- 

 resented by 37 5 inches, alcohol by 1 1 inches and so on. 

 In each case it is the coefficient for cubical expansion 

 from 32°F. to 2I2°F. that is represented by the fractional 

 numbers. If these be compared with the Table on 

 p. 44 of the 1808 edition of Part I. of the " New System" 

 it will be found that they all agree with the figures 

 given in the Table, with the exception of mercury, which 

 is given as high as ■£$. The value - 1 - is nearer the -i T 

 which Dalton quotes from the experiments of Dulong 

 and Petit, given in the 1827 edition of Part First of 

 Vol. II. of the "New System." It hence seems probable 

 that the diagram No. 30 was made after 18 19, when the 

 experiments of Dulong and Petit were published. 



Sheets 31 and 32. 



These diagrams are very similar to that given in 

 Plate 2, Part I. of the " New System," but better adapted 

 for lecture use. They both show logarithmic curves 

 representing Dalton's law for the increase of vapour 

 pressure with temperature. In the case of No. 31 a 

 diagram is added which shows a barometer tube con- 

 taining mercury with water on the surface of the mercury. 

 The tube has a heating jacket surrounding its upper part, 

 whilst the lower part is bent and graduated for pressure 

 measurements. No. 31 (22" x 33") relates to water only, 



