discovered, every considerable improvement of _Telescopes_ or _Microscopes_
producing new Worlds and _Terra-Incognita's_ to our view.

The Glasses I used were of our English make, but though very good of the
kind, yet far short of what might be expected, could we once find a way of
making Glasses Elliptical, or of some more true shape; for though both
_Microscopes_, and _Telescopes_, as they now are, will magnifie an Object
about a thousand thousand times bigger then it appears to the naked eye;
yet the Apertures of the Object-glasses are so very small, that very few
Rays are admitted, and even of those few there are so many false, that the
Object appears _dark_ and _indistinct_: And indeed these inconveniences are
such, as seem inseparable from Spherical Glasses, even when most exactly
made; but the way we have hitherto made use of for that purpose is so
imperfect, that there may be perhaps ten wrought before one be made
tolerably good, and most of those ten perhaps every one differing in
goodness one from another, which is an Argument, that the way hitherto used
is, at least, very uncertain. So that these Glasses have a double defect;
the one, that very few of them are exactly true wrought; the other, that
even of those that are best among them, none will admit a sufficient number
of Rayes to magnifie the Object beyond a determinate bigness. Against which
Inconveniences the only Remedies I have hitherto met with are these.

First, for _Microscopes_ (where the Object we view is near and within
our power) the best way of making it appear bright in the Glass, is to
cast a great quantity of light on it by means of _convex glasses_, for
thereby, though the aperture be very small, yet there will throng in
through it such multitudes, that an Object will by this means indure to
be magnifi'd as much again as it would be without it. The way for doing
which is this. I make choice of some Room that has only one window open
to the South, and at about three or four foot distance from this