come most copiously to the Eye from the Drops in the Line OH, and strike
the Senses with the deepest violet in that Region. And by the same
Argument, the Drops in the Regions between G and H shall strike the
Sense with the intermediate Colours in the Order which their Degrees of
Refrangibility require, that is, in the Progress from G to H, or from
the inside of the Bow to the outside in this order, red, orange, yellow,
green, blue, indigo, violet. And since these four Lines OE, OF, OG, OH,
may be situated any where in the above-mention'd conical Superficies;
what is said of the Drops and Colours in these Lines is to be understood
of the Drops and Colours every where in those Superficies.
Thus shall there be made two Bows of Colours, an interior and stronger,
by one Reflexion in the Drops, and an exterior and fainter by two; for
the Light becomes fainter by every Reflexion. And their Colours shall
lie in a contrary Order to one another, the red of both Bows bordering
upon the Space GF, which is between the Bows. The Breadth of the
interior Bow EOF measured cross the Colours shall be 1 Degr. 45 Min. and
the Breadth of the exterior GOH shall be 3 Degr. 10 Min. and the
distance between them GOF shall be 8 Gr. 15 Min. the greatest
Semi-diameter of the innermost, that is, the Angle POF being 42 Gr. 2
Min. and the least Semi-diameter of the outermost POG, being 50 Gr. 57
Min. These are the Measures of the Bows, as they would be were the Sun
but a Point; for by the Breadth of his Body, the Breadth of the Bows
will be increased, and their Distance decreased by half a Degree, and so
the breadth of the interior Iris will be 2 Degr. 15 Min. that of the
exterior 3 Degr. 40 Min. their distance 8 Degr. 25 Min. the greatest
Semi-diameter of the interior Bow 42 Degr. 17 Min. and the least of the
exterior 50 Degr. 42 Min. And such are the Dimensions of the Bows in the
Heavens found to be very nearly, when their Colours appear strong and
perfect. For once, by such means as I then had, I measured the greatest
Semi-diameter of the interior Iris about 42 Degrees, and the breadth of
the red, yellow and green in that Iris 63 or 64 Minutes, besides the
outmost faint red obscured by the brightness of the Clouds, for which we
may allow 3 or 4 Minutes more. The breadth of the blue was about 40
Minutes more besides the violet, which was so much obscured by the
brightness of the Clouds, that I could not measure its breadth. But
supposing the breadth of the blue and violet together to equal that of
the red, yellow and green together, the whole breadth of this Iris will
be about 2-1/4 Degrees, as above. The least distance between this Iris
and the exterior Iris was about 8 Degrees and 30 Minutes. The exterior
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