## 3-15-35. George Howard Darwin to H. Poincaré

Oct. 12.01

Newnham Grange–Cambridge

Dear Monsieur Poincaré

I have no doubt you are substantially right,^{1}^{1}
1
Poincaré
had recently charged Darwin with error (§ 3-15-34).
and I cannot now recall
the argument which made me think as I did. Is not it at least
partially true? At any rate I have made the first calculation of my
coeff^{ts} (other than ${\U0001d50e}_{3}$) for $y={75}^{\circ}$,
$\kappa =\mathrm{sin}{81}^{\circ}{5}^{\prime}$ and find

I shall go on and compute for $\kappa =\mathrm{sin}{81}^{\circ}{4}^{\prime}$ – for the Jacobian is $\kappa =\mathrm{sin}{81}^{\circ}{4.4}^{\prime}$. In this way I have an independent calculation & verification.

I have found an error in my calculation of ${\mathbf{K}}_{3}^{1}$ for
$y={69}^{\circ}50$, $\kappa =\mathrm{sin}{73}^{\circ}{56}^{\prime}$. It sh^{d} be $.299$
& not $.236$. This does not disturb the order in which the $K$’s
are arranged.

If it would be of any help to you I will send you my comp^{n} of
the critical Jacobian.

Having struggled so much with arithmetic and realised its extreme
difficulty, it is a comfort to me to hear you confess yourself a bad
calculator.^{2}^{2}
2
See Poincaré to Darwin (§ 3-15-34).

Yours sincerely,

G. H. Darwin

ALS 2p. Collection particulière, Paris 75017.

Time-stamp: "18.09.2016 01:36"