rther and farther from the direct Light; because when the
Knives approach one another till they touch, those parts of the streams
vanish last which are farthest from the direct Light.

_Obs._ 7. In the fifth Observation the Fringes did not appear, but by
reason of the breadth of the hole in the Window became so broad as to
run into one another, and by joining, to make one continued Light in the
beginning of the streams. But in the sixth, as the Knives approached one
another, a little before the Shadow appeared between the two streams,
the Fringes began to appear on the inner ends of the Streams on either
side of the direct Light; three on one side made by the edge of one
Knife, and three on the other side made by the edge of the other Knife.
They were distinctest when the Knives were placed at the greatest
distance from the hole in the Window, and still became more distinct by
making the hole less, insomuch that I could sometimes see a faint
lineament of a fourth Fringe beyond the three above mention'd. And as
the Knives continually approach'd one another, the Fringes grew
distincter and larger, until they vanish'd. The outmost Fringe vanish'd
first, and the middlemost next, and the innermost last. And after they
were all vanish'd, and the line of Light which was in the middle between
them was grown very broad, enlarging it self on both sides into the
streams of Light described in the fifth Observation, the above-mention'd
Shadow began to appear in the middle of this line, and divide it along
the middle into two lines of Light, and increased until the whole Light
vanish'd. This enlargement of the Fringes was so great that the Rays
which go to the innermost Fringe seem'd to be bent above twenty times
more when this Fringe was ready to vanish, than when one of the Knives
was taken away.

And from this and the former Observation compared, I gather, that the
Light of the first Fringe passed by the edge of the Knife at a distance
greater than the 800th part of an Inch, and the Light of the second
Fringe passed by the edge of the Knife at a greater distance than the
Light of the first Fringe did, and that of the third at a greater
distance than that of the second, and that of the streams of Light
described in the fifth and sixth Observations passed by the edges of the
Knives at less distances than that of any of the Fringes.

_Obs._ 8. I caused the edges of two Knives to be ground truly strait,
and pricking their points int