That there is a Spring, or Elastical power in the Air we live in. By which ελατνρ [elater] or Spring of the Air, that which I mean is this: That our Air either consists of, or at least abounds with, parts of such a nature, that in case they be bent or compress'd by the weight of the incumbent part of the Atmosphere, or by any other Body, they do endeavour, as much as in them lies, to free themselves from that pressure, by bearing against the contiguous Bodies that keep them bent.