28 Gee, Dal ton's Lectures and Lecture Illustrations. 



Sheet 25. 



This is drawn on rough paper and is 8 feet long and 

 7 inches wide, formed of three slips of paper pasted 

 together. It is labelled " Water Therm." and shows a long 

 thermometer with a large spherical bulb. This and 

 part of the stem up to 42 are shaded to represent the 

 water. The remainder is graduated in steps of ten 

 degrees, 52°, 62 , etc., up to 212°, the distances between 

 these divisions are gradually increased, showing the in- 

 creasing rate of expansion of the water. 



Sheet 26. 



Labelled "Old and New Scales, 32 to 212 ." A 

 diagram 27 inches long and 6 inches wide, showing 

 adjacent scales marked in steps of 10 degrees. 



Sheets 27 to 29. 



These diagrams were used to make clear the difference 

 between temperature and capacity for heat. No. 27 

 (20" X 33") shows two vessels of different capacity 

 connected by a stopcock. In No. 28 (if x 21") there 

 are three independent vessels of different sizes filled to 

 the same level with a liquid. No. 29 (19" x 14") is a 

 hydrostatic analogy relating to the " method of mixtures " 

 used in calorimetry. 



Sheet 30. 



A diagram 41 in. long and only 4m. wide. It is 

 weighted at the bottom by a piece of lead so that it will 

 hang vertically. It shows graphically the relative 

 expansion of: — 



1. Glass, etc ^ = 25. 



2. Lead, etc T yg = 86. 



3. Mercury J^ = 180. 



4- Water ^ = 465. 



