210 TENANTS OF AN OLD FARM. 



"Xow, gentlemen," I asked, "have I proved my 

 proposition ?" 



"You have come prett}^ near doing it, at all events," 

 said the Assistant. 



"Truly," said my friend, "if your fticts are quite 

 authentic, as I am bound to believe, your spider pets 

 are worthy an honorary place in the guild of civil en- 

 gineers. Indeed," he added, laughing, "I think that 

 I shall suggest this animal as the most suitable emblem 

 for our Philadelphia Engineers' Club." 



"I am sure that we all agree with those learned 

 gentlemen," remarked Abby. 



" Thank you," I returned ; " I think I shall confirm 

 your good opinion b}' going back to the geometric 

 spider, whom we left crossing her completed bridge- 

 cable to begin the building of her snare. The manner 

 in which this is done is most interesting, especially to 

 one who has a taste for mechanical work. A point 

 near the center is usually chosen — though not always — 

 and the spider proceeds first of all to lay out an irregular 

 polygon of lines which serves as the foundation or frame 

 work of the orb. Here it is," pointing to the crayon 

 figure sketched upon the paper; " and you can see that 

 such an arrangement adds to the elasticity of the orb, 

 and so increases its power to resist the force of the wind 

 and of struggling insects. 



"Next our engineer proceeds to lay in the radii or 

 'spokes' of her wheel-shaped wel). T do not mean to 

 say that she has an invariable order of action, but com- 

 monly she will start with a central diamc'tcr; as ac 



