scovery_ or _mistrusting_. But to come again to the point. The
_Irregularities_ of it are caused by three or four _coadjutors_, one of
which is, the _uneven surface_ of the _paper_, which at best appears no
smother then a very course piece of _shag'd cloth_, next the _irregularity
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_.

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