calculated in the next week sixty-seven orbits on the
supposition of so many different distances from our
surface. I laid out on a paper, which we stuck up on the
wall opposite, the formula, and then one woman and one
man attacked each set of elements, each having the
Logarithmic Tables, and so in a week's working-time the
sixty-seven orbits were completed. Seventy-seven
possible places for Io-Phoebe to be in on the
forthcoming Friday evening. Of these sixty-seven, forty-
one were observable above our horizon that night.

She was not in one of the forty-one, nor near it.

But Despair, if Giotto be correct, is the chief of
sins. So has he depicted her in the fresco of the Arena
in Padua. No sin, that, of ours! After searching all
that Friday night, we slept all Saturday (sleeping after
sweeping). We all came to the Chapel, Sunday, kept awake
there, and taught our Sunday classes special lessons on
Perseverance. On Monday we began again, and that week we
calculated sixty-seven more orbits. I am sure I do not
know why we stopped at sixty-seven. All of these were on
the supposition that the revolution of the Brick Moon, or
Io-Phoebe, was so fast that it would require either
fifteen days to complete its orbit, or sixteen days, or
seventeen days, and so on up to eighty-one days. And,
with these orbits, on the next Friday we waited for the
darkness. As we sat at tea, I asked if I should begin
observing at the smallest or at the largest orbit. And
there was a great clamor of diverse opinions. But little