ally as far as the Arc. As my observations during
these walks have no scientific value, I shall postpone an account
of what I saw to another chapter.

One curious result of this work is that the longitude of the moon may
now be said to be known with greater accuracy through the last quarter
of the seventeenth century than during the ninety years from 1750 to
1840. The reason is that, for this more modern period, no effective
comparison has been made between observations and Hansen's tables.

Just as this work was approaching completion I was called upon to
decide a question which would materially influence all my future
activity. The lamented death of Professor Winlock in 1875 left vacant
the directorship of the Harvard Observatory. A month or two later I
was quite taken by surprise to receive a letter from President Eliot
tendering me this position. I thus had to choose between two courses.
One led immediately to a professorship in Harvard University,
with all the distinction and worldly advantages associated with it,
including complete freedom of action, an independent position, and
the opportunity of doing such work as I deemed best with the limited
resources at the disposal of the observatory. On the other hand
was a position to which the official world attached no importance,
and which brought with it no worldly advantages whatever.

I first consulted Mr. Secretary Robeson on the matter. The force with
which he expressed himself took me quite by surprise. "By all means
accept the place; don't remain in the government service a day longer
than you have to. A scientific man here has no future before him, and
the quicker he can get away the better." Then he began to descant on
our miserable "politics" which brought about such a state of things.

Such words, coming from a sagacious head of a department who, one
might suppose, would have been sorry to part with a coadjutor of
sufficient importance to be needed by Harvard University, seemed to
me very suggestive. And yet I finally declined the place, perhaps
unwisely for myself, though no one who knows what the Cambridge
Observatory has become under Professor Pickering can feel that
Harvard has any cause to regret my decision. An apology for it on
my own behalf will seem more appropriate.

On the Cambridge side it must be remembered that the Harvard
Observatory was then almost nothing compared with what it is now.
It was poor in means, meagre in instru