gold. I see the ice-mountains of Saturn, hoar
through the twilight. I behold the earth rolling upon itself, from
darkness to light, and from light to darkness. I see the clouds of
winter settling over one part of it, with the nether mantle of snow
shining through them; I see in another a brown, dusky waste of sand
lighted up by the glow of summer. One ocean appears smooth as a
mirror--another is black with tempest. I see the pyramid of shade
which each of the planets casts from its darkened side into the
space behind; and I perceive the stars twinkling through each
opening, as through the angular doors of a pavilion.

"Such is the scene seen at right angles with the plane in which the
planets move; but what would be its aspect if I saw it in the line
of the plane? What would be its appearance if I saw it edgewise?
There arises in my mind one of those uncertainties which so
frequently convince me that I am ignorant. I cannot complete my
picture, for I do not know whether all the planets move in one
plane. How determine the point? A ray of light breaks in. Huzza! I
have found it. If the courses of the planets as seen in the heavens
form parallel lines, then must they all move in one plane; and
_vice versa_. But hold! That would be as seen from the sun--if the
planets _could_ be seen from the sun. The earth is but one of their
own number, and from it the point of view must be disadvantageous.
The diurnal motion must perplex. But no. The apparent motion of
the heavens need not disturb the observation. Let the course of the
planets through the fixed stars, be marked, and though, from the
peculiarity of the point of observation, their motion may at one
time seem more rapid, and at another more slow, yet, if their plane
be, as a workman would say, _out of twist_, their lines will seem
parallel. Still in some doubt, however: I long for a glance at an
Orrery, to determine the point; and then I remember that Ferguson,
an untaught man like myself, had made more Orreries than any one
else, and that mechanical contrivances of the kind were the natural
recourse of a man unskilled in the higher geometry. But it would be
better to be a mathematician than skilful in contriving Orreries. A
man of the Newtonian cast of mind, and accomplished in the
Newtonian learning