F. 1/4
  G. 1/6
  H. 1/8
  I. be 1/12 of an inch. 
  K. 1/16
  L. 1/24
  M. 1/32
  &c——­
There may be added as many more, as the Experimenter shall think fit, with holes continually decreasing by known quantities, so far as his senses are able to help him; I say, so far, because there may be made Pipes so small that it will be impossible to perceive the perforation with ones naked eye, though by the help of a Microscope, it may easily enough be perceived:  Nay, I have made a Pipe perforated from end to end, so small, that with my naked eye I could very hardly see the body of it, insomuch that I have been able to knit it up into a knot without breaking:  And more accurately examining one with my Microscope, I found it not so big as a sixteenth part of one of the smaller hairs of my head which was of the smaller and finer sort of hair, so that sixteen of these Pipes bound faggot-wise together, would but have equalized one single hair; how small therefore must its perforation be?  It appearing to me through the Microscope to be a proportionably thick-sided Pipe.

To proceed then, for the trial of the Experiment, the Experimenter must place the Tube AB, perpendicular, and fill the Pipe F (cemented into the hole E) with water, but leave the bubble C full of Air, and then gently pouring in water into the Pipe AB, he must observe diligently how high the water will rise in it before it protrude the bubble of Air C, through the narrow passage of F, and denote exactly the height of the Cylinder of water, then cementing in a second Pipe as G, and filling it with water; he may proceed as with the former, denoting likewise the height of the Cylinder of water, able to protrude the bubble C through the passage of G, the like may he do with the next Pipe, and the next, &c. as far as he is able:  then comparing the several heights of the Cylinders, with the several holes through which each Cylinder did force the air (having due regard to the Cylinders of water in the small Tubes) it will be very easie to determine, what force is requisite to press the Air into such and such a hole, or (to apply it to our present experiment) how much of the pressure of the Air is taken off by its ingress into smaller and smaller holes.  From the application of which to the entring of the Air into the bigger hole of the Vessel, and into the smaller hole of the Pipe, we shall clearly find, that there is a greater pressure of the air upon the water in the Vessel or greater pipe, then there is upon that in the lesser pipe:  For since the pressure of the air every way is found to be equal, that is, as much as is able to press up and sustain a Cylinder