The II. Tryal.
2. This done, to shew that there needed not the Spring of so great a quantity of included Air to break such Glasses, we took a∣nother Roundish one, which, though wide enough at the Orifice to cover the Brass Ring & the new Glass-plate that we had cemen∣ted on it, was yet so low, that we estimated it to hold but a 6th part of what the large Receiver, formerly imploy'd, is able to contain; and having whelm'd this smaller vessel, which was shap'd like those Cups they call Tumblers, over the Metalline Recei∣ver, and well fasten'd it to the Engine with Cement, we found that though this External Receiver had a great part of its Cavity fill'd by the included one, yet when this Internal one was exhau∣sted by an Exuction or two, the Spring of the little Air that re∣main'd, was able to break the Plate into a multitude of frag∣ments.