cent Pastboard into an hot Press, where it is kept very violently
prest, till it be dry and stiff; by which means, the wales of either
contiguous sides leave their own impressions upon each other, as is very
manifest by the second Figure, where 'tis obvious enough, that the wale of
the piece ABCD runs parallel between the pricked lines ef, ef, ef, and as
manifest to discern the impressions upon these wales, left by those that
were prest upon them, which lying not exactly parallel with them, but a
little athwart them, as is denoted by the lines of, oooo, gh, gh, gh,
between which the other wales did lie parallel; they are so variously, and
irregularly creas'd that being put into that shape when wet, and kept so
till they be drie, they so let each others threads, that the Moldings
remain almost as long as the Stuff lasts.

Hence it may appear to any one that attentively considers the Figure, why
the parts of the wale a, a, a, a, a, a, should appear bright; and why the
parts b, b, b, b, b, b, b, should appear shadowed, or dark; why some, as d,
d, d, d, d, d, should appear partly light, and partly dark: the varieties
of which reflections and shadows are the only cause of the appearance of
watering in Silks, or any other kind of Stuffs.

From the variety of reflection, may also be deduc'd the cause why a small
breez or gale of wind ruffling the surface of a smooth water, makes it
appear black; as also, on the other side, why the smoothing or burnishing
the surface of whitened Silver makes it look black; and multitudes of other
phaenomena might hereby be solv'd, which are too many to be here insisted
on.

* * * * *

Observ. VI. _Of Small Glass Canes._

That I might be satisfied, whether it were not possible to make an
_Artificial_ pore as _small_ as any _Natural_ I had yet found, I made
several attemps with small _glass pipes_, melted in the flame of a Lamp,
and then very _suddenly_ drawn out into a great length. And, by _that
means_, without much difficulty, I was able to draw some almost as small as
a _Cobweb_, which yet, with the _Microscope_, I could plainly perceive[7]
to be _perforated_, both by looking on the _ends_ of it, and by looking on
it _against the light_ which was much the _easier way_ to determine whether
it were solid or perforated; for, taking a small pipe of glass, and closing
one end of it, then filling it _half full_ of water, and holding it
_against the light_, I cou