f 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
Iris was broader than the interior, but so faint, especially on the blue
side, that I could not measure its breadth distinctly. At another time
when both Bows appeared more distinct, I measured the breadth of the
interior Iris 2 Gr. 10', and the breadth of the red, yellow and green in
the exterior Iris, was to the breadth of the same Colours in the
interior as 3 to 2.

This Explication of the Rain-bow is yet farther confirmed by the known
Experiment (made by _Antonius de Dominis_ and _Des-Cartes_) of hanging
up any where in the Sun-shine a Glass Globe filled with Water, and
viewing it in such a posture, that the Rays which come from the Globe to
the Eye may contain with the Sun's Rays an Angle of either 42 or 50
Degrees. For if the Angle be about 42 or 43 Degrees, the Spectator
(suppose at O) shall see a full red Colour in that side of the Globe
opposed to