48 



as accessary to the flight of the spider ; but the fact 

 proves that clouds are replenished with electricity, 

 and the sunbeam which impinges on them may be the 

 medium of supply : besides, the floods of heat which 

 descend to us in the sunbeams would more than 

 suffice to check or counteract these assumed emana- 

 tions ; and in the brightest sunshine, cceteris paribus, 

 the ascent of our little aeronaut will be most rapid. 

 This is not the place to discuss the phenomena of 

 the clouds ; but seeing that the solar ray will commu- 

 nicate electricity to them, and from the circumstance 

 that ammoniacal gas, by electric influence, may be ex- 

 panded into double its former volume, in all proba- 

 bility the elasticity of these aqueous reservoirs may 

 be enhanced by the same means, and their buoyancy 

 be thereby promoted. As far as we can discover, the 

 only tangible phenomenon on which Mr. Blackwall 

 hazards his conjecture is one perfectly unique, and 

 therefore sui generis ; for, as far as our information or 

 reading extends, nothing of the kind has ever been 

 seen by any other observer ; and if this be the case, 

 it is possible that it may have been a deceptio visus, or 

 some anomalous occurrence. " What more particularly 

 arrested my attention," says he, " was the ascent of 

 an amazing quantity of webs of an irregular compli- 

 cated structure, resembling ravelled silk of the finest 

 quality and clearest white : they were of various shapes 

 and dimensions, some of the largest measuring up- 

 wards of a yard in length, and several inches in 

 breadth in the widest part ; while others were almost 

 as broad as long." He proceeds to inform us that it 

 was " quickly perceived, these webs were not formed 

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

 surface." We much doubt, however, whether this 

 intuitive perception will be equally satisfactory to 



