## 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}endnote:
^{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 $\mathfrak{K}_{3}$) for $y=75^{\circ}$,
$\kappa=\sin 81^{\circ}5^{\prime}$ and find

$\displaystyle\mathfrak{K}^{1}_{3}$ | $\displaystyle=.130$ | ||

$\displaystyle\mathbf{K}^{1}_{3}$ | $\displaystyle=.224$ | ||

$\displaystyle\mathfrak{K}^{2}_{3}$ | $\displaystyle=.460$ | ||

$\displaystyle\mathbf{K}^{2}_{3}$ | $\displaystyle=.465$ | ||

$\displaystyle\mathfrak{K}^{3}_{3}$ | $\displaystyle=.604$ | ||

$\displaystyle\mathbf{K}^{3}_{3}$ | $\displaystyle=.614$ |

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

I have found an error in my calculation of $\mathbf{K}^{1}_{3}$ for
$y=69^{\circ}50$, $\kappa=\sin 73^{\circ}56^{\prime}$. 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}endnote:
^{2}
See Poincaré to Darwin (§ 3-15-34).

Yours sincerely,

G. H. Darwin

ALS 2p. Collection particulière, Paris 75017.

Time-stamp: " 4.05.2019 00:12"