of the Type_ or _Ingraving_, and a third is the _rough Daubing_ of the
_Printing-Ink_ that lies upon the instrument that makes the impression, to
all which, add the _variation_ made by the Different _lights_ and
_shadows_, and you may have sufficient reason to guess that a _point_ may
appear much more _ugly_ then _this_, which I have here presented, which
though it appear'd through the _Microscope_ _gray_, like a great splatch of
_London_ dirt, about three inches over; yet to the _naked eye_ it was
_black_ and no bigger then that in the midst of the Circle A. And could I
have found Room in this Plate to have inserted an O you should have seen
that the _letters_ were not more distinct then the _points_ of Distinction,
nor a _drawn circle_ more exactly _so_, then we have now shown a _point_ to
be a _point_.

* * * * *


Observ. II. _Of the Edge of a Razor._

The sharpest _Edge_ hath the same kind of affinity to the sharpest _Point_
in Physicks, as a _line_ hath to a _point_ in Mathematicks; and therefore
the Treaty concerning this, may very properly be annexed to the former. A
Razor doth appear to be a Body of a very neat and curious aspect, till more
closely viewed by the _Microscope_, and there we may observe its very Edge
to be of all kind of shapes, except what it should be. For examining that
of a very sharp one, I could not find that any part of it had any thing of
sharpness in it; but it appeared a rough surface of a very considerable
bredth from side to side, the narrowest part not seeming thinner then the
back of a pretty thick Knife. Nor is't likely that it should appear any
otherwise, since as we just now shew'd that a _point_ appear'd a _circle_,
'tis rational a _line_ should be a _parallelogram_.