236 Silk Manufachire. 



the gallery; the conducting line, with the ivory ball at the end was 

 passed ovbr the silken portion, and hung nine feet below this hor- 

 izontal line of suspension. The conducting line was eighty feet 

 and a half in length, one end being fastened'by a loop to the elec- 

 tric tube; upon rubbing this, the experimenters had the gratifica- 

 tion of finding that the ivory ball attracted and repelled light sub- 

 stances in the same manner as the tube itself would have done. 

 They next contrived to return the line, so that the whole length 

 amounted to 147 feet, and in this case likewise the experiment 

 ^ answered tolerably well; but suspecting that the attraction of the 

 electric fluid would be stronger if the line were not doubled, they 

 carried one straight forward through a distance of 124 feet. In 

 this anticipation they were not deceived, the attraction under these 

 circumstances being stronger than when the line was doubled. 

 Proceeding thence to add more and still more to thair conduct- 

 ing line, until at length the slender silk thread broke from the 

 weight imposed, they sought to substitute for their fragile cord a 

 small wire, first of iron and then of brass. The unsuccessful re- 

 sult, however, soon brought them to the conviction, that the refu- 

 sal of the silk to conduct the electric fluid was not owing to its 

 fineness, but proceeded from some inherent property possessed by 

 the material. The metallic wires were smaller even than their 

 silken thread had been, and yet they eflectually carried off" the 

 electricity: thicker silken cords were therefore adopted, and, as 

 before, the electric fluid was conveyed to a great horizontal dis- 

 tance, without sufi^ering any diminution of its virtue. 



' This knowledge of the non-conducting power of silk was quick- 

 ly followed by the discovery of the same quality in many other 

 substances, and thus accidentally was laid the foundation of many 

 of the subsequent improvements in the science of electricity. 



' No particular attention was paid to the electric qualities of silk, 

 nor were any experiments made on it as an electric, until the 

 year 1759. Mr. Symmer's notice was then attracted to the sub- 

 ject by the following whimsical circumstance, which led him to 

 the performance of many curious experiments. The results of 

 these he communicated to th.e Royal Society, by whom his 

 paper was inserted in the fifty-first volume of their ' Transac- 

 tions.' 



' Mr. Symmcr was in the habit of wearing at the same time 

 two pairs of silk stockings; the under pair while, and the upper 

 black. If these were pulled off together, no sign of electricity 

 appeared; but if the black stockings were pulled off from the 

 white, a snapping or crackling noise was heard; and when this 

 happened in the dark, sparks were plainly perceived between 



