CAPILLARY ATTRACTION. 



his ideas are scarcely less alarming in appearance 

 than those of Laplace, it is very easy to translate 

 them into words by which the whole theory will 

 be made perfectly intelligible to persons who 

 imagine themselves incapable of understanding 

 sextuple integrals. Let us place ourselves con- 

 veniently at the centre of the earth so as not to 

 be disturbed by gravity. Take now two portions 

 of water, and let them be shaped over a certain 

 area of each call it A for the one and B for the 

 other so that' when put together they will fit 

 perfectly throughout these areas. To save all 

 trouble in manipulating the supposed pieces of 

 water, let them become for a time perfectly rigid, 

 without, however, any change in their mutual 

 attraction. Bring them now together till the two 

 surfaces A and B come to be within the one- 

 hundred-thousandth of an inch apart, that is, the 

 forty-thousandth of a centimetre, or two hundred 

 and fifty micro-millimetres (about half the wave- 

 length of green light). At so great a distance 

 the attraction is quite insensible : we may feel very 

 confident that it differs, by but a small percentage, 



