93 
position of Mars, as also from either conjunction of Venus, 
no tolerably probable result could be deduced, by reason of 
the almost total lack of observations; and that whatever 
result was deducible must be from the first Mars-opposition 
alone. The materials here too were entirely inadequate, 
though in comparison with those for the three other series 
they seemed large; but on closer scrutiny a great portion of 
them proved not to have been made with the needful care, » 
The only result to be deduced was altogether at variance 
with that which subsequent investigations have rendered 
probable. 
Fortunately for science, and happily for Gilliss’s own 
consciousness, his observations were not limited to those 
which it was his special duty to make. Even these on 
Mars and Venus, which failed of yielding their deserved 
fruit in affording those data which they were instituted to 
obtain, are yet of priceless value in the means which they 
afford, and which will doubtless soon be made useful for im- 
proving our knowledge of the orbits of our two neighboring 
planets. 
Among other astronomical fruits of the expedition to Chile, 
I may mention the following: 7,000 meridian observations 
of 2,000 stars, chiefly the standard stars used for determining 
the errors of instrumental adjustment, and the LaCaille stars 
already mentioned. These, with their instrumental and 
tabular reductions, and a resultant catalogue of their mean 
places’ for the’ equinox of 1850.0, form a part of Vol. IV. of 
the series of the results of the expedition. The remainder 
consists of observations of Mars and Venus not included in 
the Parallax volume, and observations of the moon and 
moon-culininating stars. This volume was left ready for 
_ the press at Gilliss’s death ; and his distinguished successor, 
_ Admiral Davis, gives me the gratifying informatio ormation that he 
