500 PHILOSOPHICAL TRANSACTIONS. |^ ANNO 1701. 



viscous matter, which I took to be the beginning of their web, and not finding 

 it, I was amazed, being unable to conceive how such a strong thread could 

 in so short a time proceed out of such a moist body, strong enough to 

 bear the weight not of one only, but even six spiders ; and when I endea- 

 voured to find out the manner how they make their webs, one and the 

 same thread seemed to me sometimes to consist of a single thread, and 

 sometimes of four or five; but I could never see how the threads issued from 

 the spider's body. Since then I took a spider, and laid it on its back, so that 

 it could not stir, and with a very fine pair of pincers drew out a thread, which 

 I could perceive sticking out of one of the working instruments ; in doing 

 which I saw abundance of very fine threads coming out of the body at the 

 same time ; which, as soon as they were one or two hair's breadth distant frotn 

 the body, were joined together, and so made thick threads. Not content 

 with these my observations, I bethought myself how to fasten these fine threads 

 while they were divided, and just as they came out of the body of the spider; 

 which succeeded with me three several times, and the oftener the better. But 

 it is impossible to describe or conceive the extreme fineness of those threads ; 

 for though I used my best glasses, yet even then they appeared so small as almost 

 to escape the sight. I endeavoured to count those threads as they came out of 

 the body, but could not; for in some places I found threads that were 25 

 times as thick as others that lay next them. 



I caused the limner to look at some of these threads, as they came out of 

 the spider's body, who was forced to own that there was no describing them, 

 either with pen or pencil, and that they could hardly be engraved on copper 

 plates; however I have sent them as well done as I could, mnopu, fig. 7, pi. 13, 

 represents a part of the threads, which came out of but two of their working 

 instruments, and are divided from one another, just as they issued from the 

 body. Now, as we may perceive that a spider's web, which to our naked eye 

 seems but single, yet consists of many other threads, and thus acquires a greater 

 strength ; we may from hence certainly conclude, that no flexible bodies (ex- 

 cepting metals, whose parts are strongly cemented by the force of fire) can 

 attain to any degree of strength, unless they consist of long united parts; and 

 the more these are twisted together, or cemented with any viscous matter, 

 the stronger they are ; which is very obvious in flax, or silken thread, ropes, 

 &c. And thus also hair or wool, according to its fineness, has more or less 

 strength, because each of those hairs consists of longer and finer parts, which 

 are not only united by a viscous matter to one another, but are also armed 

 with a skin or bark, which more strictly joins the contained parts. Now if we 

 seriously reflect on the vast number of fine threads, which at once proceed 



