The electrical machine which he invented consisted of a sphere of sulphur mounted on an iron axis to imitate the rotation of the earth, and which, when rubbed, manifested electrical reactions.

When this globe was revolved and stroked with the dry hand it was found that it attached to it "all sorts of little fragments, like leaves of gold, silver, paper, etc." "Thus this globe," he says, "when brought rather near drops of water causes them to swell and puff up.

It likewise attracts air, smoke, etc."(9) Before the time of Guericke's demonstrations, Cabaeus had noted that chaff leaped back from an "electric," but he did not interpret the phenomenon as electrical repulsion.

Von Guericke, however, recognized it as such, and refers to it as what he calls "expulsive virtue." "Even expulsive virtue is seen in this globe," he says, "for it not only attracts, but also REPELS again from itself little bodies of this sort, nor does it receive them until they have touched something else." It will be observed from this that he was very close to discovering the discharge of the electrification of attracted bodies by contact with some other object, after which they are reattracted by the electric.
He performed a most interesting experiment with his sulphur globe and a feather, and in doing so came near anticipating Benjamin Franklin in his discovery of the effects of pointed conductors in drawing off the discharge.

Having revolved and stroked his globe until it repelled a bit of down, he removed the globe from its rack and advancing it towards the now repellent down, drove it before him about the room.