SPIDERS. 303 



not the power of darting their threads even through the 

 space of half an inch."* The following details are given 

 in confirmation of this opinion. Mr. Black wall observed, 

 the 1st Oct., 1826, a little before noon, with the sun 

 shining brightly, no wind stirring, and the thermometer in 

 the shade ranging from 55°. 5 to 64:^, a profusion of shining 

 lines crossing each other at every angle, forming a con- 

 fused net-work, covering the fields and hedges, and thickly 

 coating his feet and ankles, as he walked across a pasture. 

 He was more struck with the phenomenon, because on the 

 previous day a strong gale of wind had blown from the 

 south, and as gossamer is only seen in calm weather, it 

 must have been all produced within a very short time. 



" What more particularly arrested my attention," says 

 Mr. Blackwall, " was the ascent of an amazing quantity of 

 webs, of an irregular, complicated structure, resembling 

 ravelled silk of the finest quality and clearest white ; they 

 were of various shapes and dimensions, some of the largest 

 measuring upwards of a yard in length, and several inches 

 in breadth in the widest part ; while others were almost as 

 broad as long, presenting an area of a few square inches 

 only. 



" These webs, it was quickly perceived, were not formed 

 in the air, as is generally believed, but at the earth's sur- 

 face. The lines of which they were composed, being 

 brought into contact by the mechanical action of gentle 

 airs, adhered together, till, by continual additions, they 

 were accumulated into flakes or masses of considerable 

 magnitude, on which the ascending current, occasioned by 

 the rarefaction of the air contiguous to the heated ground, 

 acted with so much force as to separate them from the 

 objects to which they were attached, raising them in the 

 atmosphere to a per[3endicular height of at least several 

 hundred feet. I collected a number of these webs about 

 mid-day, as they rose ; and again in the afternoon, when 

 the upward current had ceased, and they were falling ; but 

 scarcely one in twenty contained a spider : though, on 



* Mag. Nat. Hist., vol. ii. p. 397. 



