418 



NOTES. 



NOTK 169, p. 109. Inverse ratio, &c. The elevation of the liquid is 

 greater in proportion as the internal diameter of the tube is less. 



NOTE 170, p. 110. In fig. 41, the line cd shows the direction of the 

 resulting force in the two cases. 



NOTE 171, p. 110. When two plates of glass are brought near to one 

 another in water, the liquid rises between them ; and if the plates touch 

 each other at one of their upright edges, the outline of the water will be- 

 come a hyperbola. 



NOTE 172, p. 111. Let A A', fig. 42, be two plates, both of which are 

 f et, and B B', two that are dry. When partly immersed in a liquid, its 



wet, 



Fig. 42. 



surface will be curved close to them, but will be of its usual level for the 

 rest of the distance. At such a distance, they will neither attract nor 

 repel one another. But as soon as they are brought near enough to have 

 the whole of the liquid surface between them curved, as in a a', b b', they 

 will rush together. If one be wet and another dry, as C C', they will 

 repel one another at a certain distance ; but as soon as they are brought 

 very near, they will rush together, as in the former cases. 



NOTE 173, p. 128. Latent heat. There is a certain quantity of heat 

 in all bodies, which cannot be detected by the thermometer, but which 

 may become sensible by compression. 



NOTE 174, p. 131. Reflected waves. A series of waves of light, sound, 



Fif. 43. 



