Haliburton, not strong in spherical
trigonometry, looked out logarithms for me till
breakfast, and, as soon as it would do, went over to Mrs.
Bowdoin, to borrow her telescope, ours being left at No.
9.
Mrs. Bowdoin was kind, as she always was, and at noon
Haliburton appeared in triumph with the boxes on P.
Nolan's job-wagon. We always employ P., in memory of
dear old Phil. We got the telescope rigged, and waited
for night, only, alas! to be disappointed again. Io had
wandered somewhere else, and, with all our sweeping back
and forth on the tentative curve I had laid out, Io would
not appear. We spent that night in vain.
But we were not going to give it up so. Phoebe might
have gone round the world twice before she became Io;
might have gone three times, four, five, six,--nay, six
hundred,--who knew? Nay, who knew how far off Phoebe-
Io was or Io-Phoebe? We sent over for Annie, and
she and Polly and George and I went to work again. We
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.
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