^0 AERIAL COLUMN AND AERIAL' ELECTROSCOPE, 



The pheno- 23. By comparing the last column with all the others, in the 



mena depend- paper above-mentioned, it may be seen, that there is no con-* 



edontheelec- ... . . 



trie state of ^^^xion of the ;2Jt-;noer ot sinkings with either the barometer, 



tbeatmosphere the thermometer, or ihe hydrometer, and only with the different 

 only. J JO ^ J 



days and parts of the day. Which circumstance confirmed 



me in the idea, that it was only the different electrical states of 

 the surrounding air, that produced these changes in the power 

 of the column; however obscure was still this connexion, for 

 the reasons which I explained. 

 The inquiry 24. This is a new and very interesting subject of experimen- 

 T/porster' '^' ^''^ ^^^J even natural philosophy, and in publishing it in this its 

 infancy, I hac ' ^ hope that it might lead some attentive ob- 

 server to follow it up. This hope has been realized, when I 

 have seen in your Journal, that Mr. T, Forster has under- 

 taken that investigation ; particularly as I know his talents, 

 being, since that time, personally acquainted with him. 

 Improvement 25. I shall only mention farther, that I have made a nevr 

 tus. PP^''^' step in this pursuit. Knowing by my former experiments, 

 that, though the she of the plates is indifferent to the final 

 simple divergence of the gold leaf electrometers at the extremi- 

 ties of the column, it is not the same when, one of them strik- 

 ing the side, they are reduced to the electrical state of the 

 ground ; for they rise faster and strike again, when the plates 

 are larger. Applying, therefore, this result of my former 

 experiments to the motion of a pendulum, I have constructed 

 a column, which, in two connected parts, contains 1300 

 groups, formed of zinc plates l| inch square, and equal pieces 

 oi Dutch gilt paper. This column moves a pendulum consist- 

 ing o( a gilt pith ball the size of a pea, suspended like the 

 other by a conducting thread, and placed in the same apparatus, 

 which prevents its sticking when it strikes the large bail. This 

 pendulum, guarded against the agitation of the air by a glass 

 case, moves between the two same large balls, being near one 

 inch distant from each other, and it has not ceased to strike 



gentleman, residing at present at Cumberland Lodge, near Windsor; 

 Mr. Hausemann, he has succeeded in every point, and is resolved, from 

 its utility, to construct it for the experimental philosophers who shall 

 desire it. 



during: 



