Yet more warmed by such encouragement in his ardour upon this ethereal
subject, the Doctor thus gaily speaks of it in his next letter:
“_10th December, 1798, Chelsea College._
* * * * *
“Well, but Herschel has been in town, for short spirts
and back again, two or three times, and I have had him
here two whole days. * * * I read to him the first
five books without any one objection, except a little
hesitation, at my saying, upon Bayly’s authority, that
if the sun were to move round the earth, according to
Ptolemy, instead of the earth round the sun, as in the
Copernican system, the nearest fixed star in every second
must constantly run at the rate of near 100,000 miles.
‘Stop a little!’ cries he; ‘I fancy you have greatly
under-rated the velocity required; but I will calculate
it at home.’ And, on his second visit, he brought me a
slip of paper, written by his sister, as he, I suppose,
had dictated. ‘Here we see that Sirius, if it revolved
round the earth, would move at the rate of 1426 millions
of miles per second. Hence the required velocity of
Sirius in its orbit would be above 7305 times greater
than that of light.’ This is all that I had to correct of
doctrine in the first five books! And he was so humble as
to protest that I knew more of the _history_ of astronomy
than he did himself; and that I had surprised him by the
mass of information that I had gotten together.
“In arranging another lecture, he flattered me much in a
note, by saying that, if I should be disengaged on a day
that he mentioned, it would give him pleasure to devote
it to the continuation of ‘our’ poetical history. This is
adoption!
“He came, and his good wife accompanied him; and I read
four books and a half. * * * And on parting, still more
humble than before, or still more amiable, he thanked me
for the instruction and entertainment I had given him!
“What say you to that? ‘Can anything be grander?’ And
all without knowing a word of what I have written of
himself; all his discoveries, as you may remember, being
kept back for the twelfth and last book. Adod! I begin to
be a little conceited! * * * So God bless you, the dear
Gardener, and the Alexandretto.
“But hold! on the first evening Herschel spent at
Chelsea, when I called for my Argand lamp, Herschel, who
had not seen one of those lamps, was surprised at the
great effusion of light; and immediately calculated the
difference between that and a single candle, and found it
as sixteen to one.”