36 SEVENTH REPORT—1837. 
Uranie in 1817-1821. Having heard that I was engaged in 
drawing up this report for the British Association, Capt. de 
Freycinet, unsolicited, did me the honour to propose to place 
his observations, hitherto unpublished, in my hands, to be 
communicated to the public through this channel. I should 
certainly fail if I attempted to express my sense of this act 
of great liberality ; happily it needs no comment; and I will 
only observe, that it adds another instance, but a very strong 
one, to those already noticed, of the good feeling that has pre- 
vailed amongst the persons by whom these inquiries have 
been carried forward. The world hears more than enough 
of the jealousies and enmities which too often disfigure the 
history and embitter the pursuits of science; it is right that 
the instances to the contrary should not always be passed in 
silence. 
The manuscript of the observations was accompanied by the 
following remarks from Capt. de Freycinet. 
‘* J’ai mis une grande attention a ce qu'il ne se glissa pas de 
faute dans la copie; et telle qu’elle est je crois que vous pou- 
vez compter sur son exactitude. L’experience a prouvé que 
les aiguilles Nos. 7 et 8, dont je me suis servi, ont perdu un 
peu de leur magnétisme pendant le voyage ; il sera facile d’en 
tenir compte, comme aussi des légéres altérations qui auront eu 
pour cause les variations de température ; mais je ne me suis 
pas livré 4 ces considérations, pensant qu'il valait mieux que 
vous vous en occupassiez selon vos vues particuliéres.” 
The table in pages 38 and 89 contains the observations, 
printed from this manuscript without alteration of any kind. 
In compliance with the wish expressed by Capt. de Frey- 
cinet, I proceeded to calculate the results of these observations 
in the following manner. The consideration of No. 9 was put 
aside in the first instance for the reason assigned in the mar- 
ginal note to the observations at the Isle of France. The 
times of vibration at Paris before and after the voyage, con- 
firmed by the observations at Rio de Janeiro in 1817 and 1820, 
show that Nos. 7 and 8 both slightly lost magnetism, and No. 8 
rather more than No. 7. It further appears that the extra 
loss of No. 8 over No. 7 was all sustained in the first fourteen 
months ; as at the Isle of France in June, 1818, they had arrived 
nearly at an equality in their time of vibration, which they pre- 
served for the whole remainder of the voyage, and exhibited 
on the return to Paris. In whatever way, therefore, we may 
proportion the equal loss sustained by both needles, the extra 
loss of No. 8 must be placed before the arrival at the Isle of 
France. When there are no circumstances in the observations 
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