nus_, not taken into
account because unknown. My first idea was to ascertain some
approximate place of this supposed body empirically, and then with
my large reflector set to work to examine all the minute stars
thereabouts: but I found myself totally inadequate to the former part
of the task. If I could have done it formerly, it was beyond me now,
even supposing I had the time, which was not the case. I therefore
relinquished the matter altogether; but subsequently, in conversation
with Bouvard, I inquired if the above might not be the case: his
answer was, that, as might have been expected, it had occurred to
him, and some correspondence had taken place between Hansen and
himself respecting it. Hansen's opinion was, that one disturbing body
would not satisfy the phenomena; but that he conjectured there were
two planets beyond _Uranus_. Upon my speaking of obtaining the places
empirically, and then sweeping closely for the bodies, he fully
acquiesced in the propriety of it, intimating that the previous
calculations would be more laborious than difficult; that if he had
leisure he would undertake them and transmit the results to me, as
the basis of a very close and accurate sweep. I have not heard from
him since on the subject, and have been too ill to write. What is
your opinion on the subject? If you consider the idea as possible,
can you give me the limits, roughly, between which this body or those
bodies may probably be found during the ensuing winter? As we might
expect an eccentricity [inclination?] approaching rather to that of
the old planets than of the new, the breadth of the zone to be
examined will be comparatively inconsiderable. I may be wrong, but I
am disposed to think that, such is the perfection of my equatoreal's
object-glass, I could distinguish, almost at once, the difference of
light of a small planet and a star. My plan of proceeding, however,
would be very different: I should accurately map the whole space
within the required limits, down to the minutest star I could
discern; the interval of a single week would then enable me to
ascertain any change. If the whole of this matter do not appear to
you a chimaera, which, until my conversation with Bouvard, I was
afraid it might, I shall be very glad of any sort of hint respecting