CHAP. I.
The Introduction, containing the order of the ensuing Enquiries.
AMong the many Experi∣ments of latter Ages, there hath been invented that Engine that commonly goes under the name of the Torricellian Experiment, which is but this: A Glass-Tube of three foot or more long, closed at one end, and then filled with Mercury or Quick∣silver, and then the open end stopped with the finger, and inverted into a vessel of restagnant Mercury & and when the end is sufficiently immersed, then the finger nimbly removed so that