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Chap. 135. Of thunder and lightning.
THunder and lightning are caused from watry circles, for when they are extended from water to vapor, from vapor to air, from temperate air, to hot air, from hot air to fire; for if those circles extended beyond the compasse, and strength of the line, they break, which is the cause of thunder, and lightning; for assoon as the farthest extention of the circle is broken, those extended parts do with an extraordinary swift motion run, or rather shut forth into bright flaming flashes, as spinning lines of light, but when those lines extend with a strong strength, they break into smal parts, which causeth thunder to follow lightnings; for those bteaking parts some∣times expulse disorderly, beating and striking upon those circle lines that are unbroke, which circles being of a hollow figure, cause a sound in the higher region, whereto they are ascended, for their extention causeth them to be light, their lightnesse to ascend; But all hollow figures being concave within, and convex without, do present to the ear, if they be strong, as concave, and convex glasses doth objects, when pre∣sented to the eye; thus hollow figures cause a hollow sound if they be struck, for the concave draws those motions in which rebounds from fide to side, and the rebounds continue 〈◊〉〈◊〉 sound by the Echos repeated, for sound lasts longer in hollow figures, then in any other, and though I will not say that onely hollow figures make sounds, yet I say that no sound can enter but through hollow figures, as the ear is a hollow fi∣gure, and all hollow figures, and the ear is not onely hol∣low, but circular, but sounds are made in the ear, or rather enters, as light and colours in the eyes, for discord is pertur∣bed motion, or rather close Antipathetical motions, and har∣mony are sympathetical, and regular motions, but the more of these extenuating circles break, the more lightning there is, and the stronger they brea, the more thunder rhere is, and the har∣der they strike upon the unbroken circles the lowder is the sound.
But if the circle lines break onely asunder, and extend, or shut forth into straight lines without more parts, there is one∣ly lightning without thunder, but if those lines break into more parts, there is thunder also, and when there falls r ain at those times of thunder, it is when the gentler motions of some of those expulsed parts, do not strike hard upon some of those unbroken circles, but presse upon them, which caus∣eth them to draw, and gather into a lesse circle, and a grosser line, untill they return into the watry compasse, where grow∣ing too heavy for the hight, falls down toward the center of the earth, as all heavie bodies, if not thick bodies under to bear them up, or stronger motions then their weight to hold them