Building the Web 207 



to counteract them, would distort the work by 

 their straining, would even destroy it for lack 

 of a stabler support. Before continuing, it is 

 necessary to lay a converse group which will 

 maintain the whole by its resistance. Any 

 combination of forces acting in one direction 

 must be forthwith neutralized by another in the 

 opposite direction. This is what our statics 

 teach us and what the Spider puts into practice ; 

 she is a past mistress of the secrets of rope- 

 building, without serving an apprenticeship. 



One would think that this interrupted and 

 apparently disordered labour must result in a 

 confused piece of work. Wrong : the rays are 

 equidistant and form a beautifully-regular orb. 

 Their number is a characteristic mark of the 

 different species. The Angular Epeira places 

 21 in her web, the Banded Epeira 32, the Silky 

 Epeira 42. These numbers are not absolutely 

 fixed ; but the variation is very slight. 



Now which of us would undertake, off-hand, 

 without much preliminary experiment and with- 

 out measuring-instruments, to divide a circle 

 into a given quantity of sectors of equal width ? 

 The Epeirse, though weighted with a wallet and 



