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Royal Observatory, Greenwich
1859 November 29

My dear Sir
You will perceive, from the statement
below, the nature of the difficulties which I have
felt in observing the small planets, and the
way in which I am endeavoring to escape from them,
by the assistance of observers who use large Equatorials.
Can you assist me in this?

The construction of the Meridional Instrument, and the general arrangements in
this Observatory, offer great advantages for the meridional observations of the small Planets;
and it has been my wish to maintain these observations with the utmost practicable regularity.
This, however, can be done only with the aid of a very approximate ephemeris.
In general, ephemerides of the small planets are not wanting; but their errors are
frequently so large as to make it nearly impossible for observers to assure themselves that the
object which they see in the meridional telescope is the planet which they are seeking. A
great amount of labour is thus wasted. And finally, I have been compelled to lay down as a
general rule, that small planets are not to be sought on the meridian, unless we have a pretty
accurate knowledge of the error of the ephemeris.
It is much to be wished that information on the magnitude of the error could be
furnished to me before the meridional observations commence. As good extrameridional
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