As for Double-Tides, they are occasioned through the Irregular dividing of the Half-Circle; as, when they divide not orderly, but faster than they orderly should do; which, falling back in a Crowd, and being, by that means, obstructed, so that they cannot get forward, they are necessitated to flow, where they ebb'd.
The reason the Tides flow through Streams of Running-waters, is, That the Tide is stronger than the Stream: but, if the Stream and Tides pass through each other, then the Tide and Stream are somewhat like Duellers together, which make Passes and Passages for their conveniency.
[CHAP. XX. Of the Figure of Ice and Snow.]
A Circle may not only extend and contract it self without dividing; but may draw it self into many several Figures, as Squares, or Triangles: as also, into many other Figures mix'd of Squares, Triangles, Cubes, or the like; being partly one, and partly, another; and into other several ways, and after several manners; which is the reason, Water may appear in many several Postures of Snow, Ice, Hail, Frost, and the like: and, in my Opinion, when the Water-Circle is Triangular, it is Snow; when the Circle is Square, it is Ice: as for Hail, they are but small pieces of Ice; that is, small Parts, or few Drops of Water, changed into Ice; and those several Parts moving after several manners, make the Exterior Figures, after several shapes; as, great Bodies of Ice will be of many several shapes, occasioned by many or fewer Parts, and by the several Postures of those Parts: but, such Figures, though they are of Ice, yet, are not the Innate Figures of Ice. The same is to be said of Snow. But, the reason of these my Opinions concerning the Figures of Ice and Snow, is, That Snow is leighter than the Water it self; and Ice is heavier, at least, as heavy. And the reason Snow is so leight, is, That a Triangular Figure hath no poyse, being an odd Figure; whereas a Square is poysed by Even and Equal Lines, and just Number of Points, as, Two to Two: but, a Triangle is Two to One. Also, a Circle is a poysed Figure, as being equal every way, from the Center to the Circumference; and from the Circumference to the Center, all the Lines drawing to one Point. But, mistake me not; for I treat (concerning the Figures of Snow and Ice) only of those Figures that cause Water to be Snow or Ice; and not of the Exterior Figures of Snow and Ice, which are occasioned by the Order or Disorder of Adjoining Parts: for, several Parts of Water, may order themselves into numerous several Figures, which concern not the nature of Water, as it is Water, Snow, or Ice: As for example, Many Men in a Battel, or upon Ceremony, joyn into many several Figures or Forms; which Figures or Forms, are of no concern to their Innate Nature. Also, the several Figures or Forms of several Houses, or several sorts of Building in one House, are of no concern to the Innate Nature of the Materials. The like for the Exterior Figures of Ice and Snow; and therefore Microscopes may deceive the Artist, who may take the Exterior for the Interior Figure; but there may be great difference between them.
[CHAP. XXI. Of the Change and Rechange of Water.]
Water being of a Circular Figurative Motion, is, as it were, but one Part, having no divisions; and therefore can more easily change and rechange it self into several Postures, viz. into the Posture of a Triangle, or Square; or can be dilated or extended into a larger compass, or contracted into a lesser compass; which is the cause it can turn into Vapour and Vaporous Air; or into Slime, or into some grosser Figure: For example, Water can extend it self beyond the proper degrees of Water, into the degree of Vapour; and the Circle, extending further than the degree of a Vaporous Circle, is extended into a Vaporous Air; and if the Vaporous Airy Circle be extreamly extended, it becomes so small, as it becomes to be a sharp Edg, and so, in a degree, next to Fire; at least, to have a hot Effect: but, if it extends further than an Edg, the Circle breaks into Flashes of Fire, like Lightning, which is a flowing Flame: for, being produced from Water, it hath the property of Flowing, or Streaming, as Water hath, as we may perceive by the Effects of some few Parts of Water flung on a bright Fire; for those few drops of Water being not enough to quench the Fire, straight dilate so extreamly, that they break into a Flame; or else cause the Fire to be more brisk and bright: and as the Water-Circle can be turned into Vapour, Air, and Flame, by Extension; so, it can be turned into Snow, Hail, or Ice, by Contraction.