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PLATE VIIL 



Shews the ftrudlure of Mr. Bennet's ekaric Doubler, applied to the pendulum of a clo 

 for the purpofe of fubjeding a flower pot to perpetual pofitive or negative elearicity. 



r 



fulated 



on which the elec-. 



tricity is accumulated. B the brafs plate, which becomes eledrified by the influence of the 



moving plate C, which is alfo infulated. 



D 



C is infulated by 



the glafs-tube E E. The wire F F is alfo infulated by the fame glafs, being faftened to 

 the middle of it by a brafs focket at G. H H H H H are wires to conned the plates with- 

 each other, or with the earth. I 1 a firing to be carried from the plate A over infulated- 

 hooks to any part of a room, or to an infulated flower-pot. 



Now if A be p®fitive, and C moves, till it be parallel to it, and the wires at the bot- 

 tom touch each other, then C becomes negative, and moving till it be parallel to B, and 

 its wire touched by the uppermofl H, then B becomes pofitive ; and when C returns to- 

 A, the eledlricity of A and B becomes united by means of the infulated wire FF touch- 

 ing H H. The longer end of F is bent fo as not to touch the wire of B, till the end Is 



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brought to it. Thus the pofitive cle6lricity of A is increafed. 



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The wires are curled into feveral rings to make them more elaftic, as otherwife they 

 would focn be puflied out of their places, and the proper contacts not occur. The plates 

 A and B may be fixed on heavy pedeftals, that they may be moved upon a flielf to a pro- 

 per diflance from the plate, which hangs by the pendulum wire. The heavier the pen- 

 dulum and the larger the plates, the more ele6lricity may be accumulated, 

 fmall apparatus fixed to a Dutch wooden clock fparks are fometimes produced between 

 the plates, and fomefunes the clock has been flopped by their attraction to each other. 

 Perhaps the plates fliould not be circular, but fomething like a lady's fan, when expand- 

 ed, the bottom being a part of the curve defcribed by the moving pendulum, with the 

 fides dire6led towards the point on which it moves. 



This drawing and defcription of his Pendulum Doubler was fent me by Mr. Bennet of 



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If another in- 



fulated flower-pot Was connected with the plate B inftsad of the wire at the uppermofl: 

 H, perhaps it might be kept in a fl:ate of minus, or negative eledricity, at the fame time 

 that the other flower-pot was kept in a ftate of plus or pofitive electricity. 



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