Though the position of the Lunar Terminator is given for mean midnight
throughout the year in that very useful publication the Companion to the
Observatory, it is frequently important in examining or comparing former
drawings and observations to ascertain its position at the times when
they were made. For this purpose the subjoined tables (which first
appeared in the Selenographical Journal) will be found useful, as they
give for any day between A.D. 1780 and A.D. 1900 the selenographical
longitude of the point where the terminator crosses the moon's equator,
which it does very nearly at right angles.
[Tables and examples]