Fair Weather. Natural Phylosophy is the Art of deducing the generall laws and properties of material substances, from a series of analogous observations. The manner of reasoning in this art is not strictly demonstrative, and by Consequence the knowledge hence acquired, not absolutely Scientifical, because the facts that we reason upon, are perceived by Sence and not by the internal Action of the mind Contemplating its Ideas. But these Facts being presumed true in the form of Axioms, subsequent reasonings about them may be in the strictest sence, scientifical. This Art informs us, in what manner bodies will influence us and each other in given Circumstances, and so teaches us, to avoid the noxious and imbrace the beneficial qualities of matter. By this Art too, many curious Engines have been constructed to facilitate Business, to avert impending Calamities, and to procure desired advantages.