NATURAL HISTORY OF SELBORNE. 435 
Showers of Cobwebs, p. 189. — An excellent account of 
aeronautic spiders has been published in " Kesearches in 
Zoology," by John Blackwall (Van Voorst, Paternoster Row, 
1873). Mr. Blackwall writes, as regards a shower of cobwebs : — 
"A little before noon on the 1st of October, 1826, which was 
a remarkably calm sunny day, I observed that the fields and 
hedges in the neighbourhood of Manchester Avere covered over 
by the united labours of an immense multitude of spiders, 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 my feet and ankles were thickly coated with 
them. It was evident, however, notwithstanding their great 
abundance, that they must have been produced in a very short 
space of time. 
" From contemplating this display of gossamer, my thoughts 
were naturally directed to the animals which produced it; and 
the countless myriads in which they swarmed almost created as 
much surprise as the singular occupation that engrossed them. 
Apparently actuated by the same impulse, all were intent upon 
traversing the regions of air ; accordingly, after gaining the 
summit of various objects, as blades of grass, stubble, rails, 
gates, &c., by the slow and laborious process of climbing, they 
raised themselves still higher by straightening their limbs ; and 
elevating the abdomen, by bringing it from the usual horizontal 
position into one almost perpendicular, they emitted from their 
spinning apparatus a small quantity of the glutinous secretion 
with which they fabricate their silken tissues. This viscid 
substance being drawn out by the ascending current of rarefied 
air into fine lines several feet in length, was carried upwards, 
until the spiders, feeling themselves acted upon with sufticient 
force in that direction, quitted their hold of the objects on 
which they stood and commenced their journey by mounting 
aloft." 
Mr. Blackwall's experiments on these spiders are very 
interesting. 
Silk of Spider. — Mr. Groom Napier w^rites : — " I gathered 
about 200 cocoons of the garden spider ; these being wound 
with a common silk reel, were twisted into thread of different 
thicknesses, which I again twisted into cord, some as fine as 
purse silk, others as thick as whipcord, but had only a few 
inches of each length. This being tested against the thread of 
the common silkworm of similar weight, proved to be twice as 
strong. The great objection to this silk for ornamental purposes 
F F 2 
