ANNALS OF THE ACADEMY 247) 
undertaken because the vessel was heavily armored and the 
voyage extended far into both hemispheres, thus affording a 
favorable opportunity of submitting Poisson’s theory of the 
deviations of compasses on iron ships to the test of rigorous 
observations, which had never been done before.” ‘The obser- 
vations were published in the Smithsonian Contributions to 
Knowledge,* with the following prefatory note by Joseph 
Henry: 
“This paper was originally an official report presented to the Navy Department 
by Professor Harkness; but, as that department made no use of it, the National 
Academy of Sciences, in August, 1867, passed a resolution asking for the manu- 
script. This request was complied with; and, an abstract of the paper having 
been read to the Academy in April, 1869, it was referred to a commission 
consisting of the President of the Academy, Professors J. H. C. Coffin, and 
F. Rogers, in accordance with whose recommendation it is now published by the 
Smithsonian Institution.” 14 
About 40 papers were read at the two sessions of 1869 and 
an equal number the preceding year. They covered a very wide 
range of topics, but the majority related to the physical sciences. 
Although in 1868 the Academy rejected the proposition to 
have the restriction on the number of members removed, the 
subject was revived in 1870 and met with favorable considera- 
tion. A resolution was unanimously passed providing that 
‘““a memorial be addressed by the President of the Academy to 
the Congress of the United States, asking for the amendment of 
its charter in such manner as to remove the restrictions to the 
number of its members.” The matter was presented to Congress 
on May 4, 1870, by Senator Henry Wilson, and the amend- 
ment asked for was granted in an act approved on July 15, 
“Vol. 18, 1873. The paper was accepted for publication on September 18, 1871. The 
signatures are dated from December, 1871, to January, 1873. 
“The resolution asking for the manuscript will be found in the Report of the National 
Academy of Sciences for 1867, page 9 (goth Congress, 2d Session. Sen. Misc. Doc. no. 106). 
The preface above quoted is not in accord with the Proceedings, which, on page 73, state 
that the committee was appointed in April, 1869, also (page 75) that Professor Harkness 
read a paper on magnetic deviations in iron ships, in April, 1870, and not in April, 1869. 
In both the Proceedings and the Report, the vessel is incorrectly referred to as the 
Miantonomah. 
