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Micrographia - Some Physiological Descriptions of Minute Bodies Made by Magnifying Glasses with Observations and Inquiries Thereupon by Robert Hooke
page 49 of 465 (10%)

Now for the drawing this second Figure[3] (which represents a part of the
Edge about half a quarter of an inch long of a Razor well set) I so plac'd
it between the Object-glass & the light, that there appear'd a reflection
from the very Edge, represented by the white line abcdef. In which you may
perceive it to be somewhat sharper then elsewhere about d, to be indented
or pitted about b, to be broader and thicker about c, and unequal and
rugged about e, and pretty even between ab and ef. Nor was that part of the
Edge ghik so smooth as one would imagine so smooth bodies as a Hone and Oyl
should leave it; for besides those multitudes of scratches, which appear to
have raz'd the surface ghik, and to cross each other every way which are
not half of them exprest in the Figure, there were several great and deep
scratches, or furrows, such as gh and ik, which made the surface yet more
rugged, caus'd perhaps by some small Dust casually falling on the Hone, or
some harder or more flinty part of the Hone it self. The other part of the
Razor ll, which is polish'd on a grinding-stone, appear'd much rougher then
the other, looking almost like a plow'd field, with many parallels, ridges,
and furrows, and a cloddy, as 'twere, or an uneven surface: nor shall we
wonder at the roughnesses of those surfaces, since even in the most curious
wrought Glasses for _Microscopes_, and other Optical uses, I have, when the
Sun has shone well on them, discover'd their surface to be variously raz'd
or scratched, and to consist of an infinite of small broken surfaces, which
reflect the light of very various and differing colours. And indeed it
seems impossible by Art to cut the surface of any hard and brittle body
smooth, since _Putte_, or even the most curious _Powder_ that can be made
use of, to polish such a body, must consist of little hard rough particles,
and each of them must cut its way, and consequently leave some kind of
gutter or furrow behind it. And though Nature does seem to do it very
readily in all kinds of fluid bodies, yet perhaps future observators may
discover even these also rugged; it being very probable, as I elsewhere
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