THE FORCE OF GRAVITATION 



17 



when a boy. I read it in a conjuring book, and this was how 

 the problem was put to us : " How," as the book said, " how 

 to hang a pail of water, by means of a stick, upon the side of 

 a table" (Fie. 8). Now I have here a table, a piece of 

 stick, and a pail, and the proposition is, how can that pail 

 be hung to the edge of this table? It is to be done, and 

 can you at all anticipate what arrangement I shall make to 

 enable me to succeed? Why this. I take a stick, and put 

 it in the pail between the bottom and the horizontal piece 



FIG. 8 



FIG. 9 



of wood, and thus give it a stiff handle, and there it is ; and, 

 what is more, the more water I put into the pail, the better 

 it will hang. It is very true that before I quite succeeded I 

 had the misfortune to push the bottoms of several pails out; 

 but here it is hanging firmly (Fie. 9), and you now see 

 how you can hang up the pail in the way which the conjuring 

 books require. 



Again, if you are really so inclined (and I do hope all of 

 you are), you will find a great deal of philosophy in this 

 [holding up a cork and a pointed thin stick about a foot 

 long]. Do not refer to your toy-books, and say you have 

 seen that before. Answer me rather, if I ask you, have you 

 understood it before? It is an experiment which appeared 

 very wonderful to me when I was a boy. I used to take 

 a piece of cork (and I remember I thought at first that it was 

 very important that it should be cut out in the shape of a 

 man, but by degrees I got rid of that idea), and the problem 



