There is great difficulty in correcting the
residual fault, not only because an inconceivably small movement of
the weights on the balance-curve is required, but also because it
endangers the equilibrium of the balance. The mechanism adopted to
remedy the defect is described in a Paper in the Horological Journal
of July 1875 by Mr W. Ellis, and has received the approval of some
able chronometer-makers.--With respect to the Transit of Venus
Expeditions: The parties from Egypt and Rodriguez are returned. I am
in continual expectation of the arrival of the other parties. I
believe the eye-observations and the ordinary photographs to be quite
successful; I doubt the advantage of the Janssen; one of the
double-image-micrometers seems to have failed; and the
Zenith-telescope gives some trouble. At three stations at Rodriguez,
and three at Kerguelen, the observations appear to have been most
successful. At the Sandwich Islands, two of the stations appear to
have been perfectly successful (except that I fear that the Janssen
has failed), and a rich series of lunar observations for longitude is
obtained. At New Zealand, I grieve to say, the observations were
totally lost, entirely in consequence of bad weather.
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