of the
Reflections of light, which is caus’d
by the various
shape of the Particles, or little
protuberant parts of the thread that compose the surface;
and that those parts of the waves that appear the brighter,
throw towards the eye a multitude of small reflections
of light, whereas the darker scarce afford any.
The reason of which reflection, the
Microscope
plainly discovers, as appears by the Figure. In
which you may perceive, that the brighter parts of
the surface consist of an abundance of large and strong
reflections, denoted by a, a, a, a, a, &c. for the
surfaces of those threads that run the
long way,
are by the Mechanical process of watering,
creas’d
or
angled in another kind of posture then they
were by the weaving: for by the weaving they
are onely
bent round the warping threads; but
by the watering, they are
bent with an angle, or
elbow, that is in stead of lying, or being bent
round the threads, as in the third Figure,
a, a, a, a, a, are about b, b, b (b, b, b representing
the ends, as ’twere, of the cross threads, they
are bent about) they are creas’d on the top
of those threads, with an
angle, as in the fourth
Figure, and that with all imaginable variety; so that,
whereas before they reflected the light onely from
one point of the round surface, as about c, c, c, they
now when water’d, reflect the beams from more
then half the whole surface, as de, de, de, and in
other postures they return no reflections at all from
those surfaces. Hence in one posture they compose
the brighter parts of the waves, in another the darker.
And these reflections are also varied, according as
the particular parts are variously bent. The reason
of which creasing we shall next examine; and here
we must fetch our information from the Mechanism or
manner of proceeding in this operation; which, as I
have been inform’d, is no other then this.
They double all the Stuff that is to be water’d,
that is, they crease it just through the middle of
it, the whole length of the piece, leaving the right
side of the Stuff inward, and placing the two edges,
or silvages just upon one another, and, as near as
they can, place the wale so in the doubling of it,
that the wale of the one side may lie very near parallel,
or even with the wale of the other; for the nearer
that posture they lie, the greater will the watering
appear; and the more obliquely, or across to each
other they lie, the smaller are the waves. Their
way for folding it for a great wale is thus:
they take a Pin, and begin at one side of the piece
in any wale, and so moving it towards the other side,
thereby direct their hands to the opposite ends of
the wale, and then, as near as they can, place the
two opposite ends of the same wale together, and so
double, or fold the whole piece, repeating this enquiry
with a Pin at every yard or two’s distance through
the whole length; then they sprinkle it with water,
and fold it the longways, placing between every fold