The Life of the Spider 



tioned within the strictly defined reahn of the 

 imagination? Not at all: the catenary ap- 

 pears actually even time that weight and 

 flexibility act in concert. The name is given 

 to the curve formed by a chain suspended by 

 two of its points which are not placed on a 

 vertical line. It is the shape taken by a flex- 

 ible cord when held at each end and relaxed; 

 it is the line that governs the shape of a sail 

 beUying in the wind; it is the curve of the 

 nanny-goat's miUc-bag when she returns from 

 filling her trailing udder. And aU this 

 answers to the number e. 



\Miat a quantity of abstruse science for a 

 bit of string! Let us not be surprised. A 

 pellet of shot swinging at the end of a thread, 

 a drop of dew trickling down a straw, a 

 splash of water rippling under the kisses of 

 the air, a mere trifle, after all, requires a 

 titanic scaffolding when we wish to examine it 

 with the eye of calculation. We need the club 

 of Hercules to crush a fly. 



Our methods of mathematical investigation 

 are certainly ingenious; we cannot too much 

 admire the mighty brains that have invented 

 them; but how slow and laborious they appear 

 when compared with the smallest actualities! 

 398 



