THE AERONAUTIC OR BALLOONING HABIT. 277 



the entire town. A gentleman from Hexham, a town twenty miles from 

 Newcastle, reported that they were abundant there also. The spiders were 

 unknown up to that time, Mr. Blackwall not having described them in 

 his elaborate work on the " Spiders of Great Britain and Ireland," only 

 liaving noticed them in the "Annals of Natural History" in 1803, previous 

 to which time they had not been observed in England. No one liad ob- 

 served this spider in the neighborhood of Newcastle up to the time of 

 their appearance, and they disappeared as suddenly as they came. Ac- 

 cording to Mr. Blackwall, the spider is an aeronautic species, Neriene 

 dentipalpis. 



One of the most temperate descriptions of a gossamer shower I quote 

 from Mr. Blackwall. A little before noon on an October day which was 

 remarkably calm and sunny, with the thermometer in the shade 

 Black- ranging from fifty-five to sixty-four degrees, Mr. Blackwall ob- 

 . ,. "served that the fields and hedges in the neighborhood of Man- 

 chester, England^ were covered over with a profusion of fine, glossy 

 lines, intersecting one another at every angle and forming a confused kind 

 of network. So extremely numerous were these slender filaments that in 

 walking across a small pasture his feet and ankles were thickly coated 

 with them. It was evident, however, notwithstanding their great abun- 

 dance, that they must have been iiroduced in a very short sjjace of time, for 

 early in the morning they had not attracted his notice. 



A circumstance so extraordinary could not fail to excite the curiosity 

 of so keen an observer. But what more particularly arrested his attention 

 was the ascent of an amazing quantity of webs of irregular and compli- 

 cated structure, resembling raveled silk of the finest quality and clearest 

 white. They were of various shapes and dimensions, some of the longest 

 measuring upwards of five feet 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. Mr. Blackwall quickly perceived that 

 these gossamer threads were not formed in the air, as was gen- 

 ^^^^ ' erally supposed at that time (1826) even among naturalists, Init 

 at the earth's surface. The lines of which they were composed 

 being brought into contact by the mechanical action of gentle airs, adliered 

 together, until by continual additions they were accumulated into flakes or 

 masses of considerable magnitude. On these masses of spinningwork the 

 ascending current, occasioned by the rarefaction of the air contiguous to 

 the heated ground, acted with so much force as if) separate them from 

 the objects to which they were attached, raising them in the atmosphere 

 to a perpendicular height of at least several hundred feet. 



About midday Mr. Blackwall collected a number of these webs as they 

 arose, and again in the afternoon, when the upturned current had ceased 

 to support them and they were falling. Scarcely one in twenty contained 

 a spider, though on minute inspection he found small winged insects, 



