The works of the Honourable Robert Boyle, Esq., epitomiz'd by Richard Boulton ... ; illustrated with copper plates.

EXPERIMENT IV.

To shew that what we have taught of the Na∣ture of Fluids, will hold in Water as well as Air, if the Pressure be uniform, we enclosed an Egg in a Bladder almost full of Water, and put∣ting it into the Brass Cylinder, we heaped up∣on the Plug as many Weights as amounted to seventy five pound, yet the Egg being taken out, was as found as when first put in. In which In∣stance it cannot be pretended, that the Egg bore no weight, by those that allow not Water to gravitate in Water, since there was a consi∣derable Pressure made by Metalline Weights, which every body allows to weigh in Water. From this Experiment, and the other before mention'd, of an Egg being broke by a partial

Pressure, it appears, that the Strength of the Texture of a Humane Body, together with the Uniformity of the Pressure of ambient Water, may be the reasons why Divers feel no greater Inconveniency under Water; for tho' their Thorax may be a little more compressed than other Parts, yet that Part being naturally dila∣ted and contracted, a little Pressure may make no sensible Alteration: But I have been told by a Diver, that at a consicerable Depth, he per∣ceived a painful Pressure upon the Drums of his Ears, 'till he contriv'd a way to guard them from that Inconveniency; the reason of which Phaenomenon seemed to be no other, than that in that Part there was not an equal internal Pressure, to resist and counterballance the ex∣ternal Pressure of the Water.