r motion, produced {349} much the same
result as Herschel. Mr. E. Dunkin,[656] one of Mr. Airy's staff at
Greenwich, applied Mr. Airy's method to a very large number of stars, and
produced, again, nearly the same result as before. This paper was read to
the Astronomical Society in _March_, 1863, was printed in abstract in the
_Notice_ of that month, was printed in full in the volume then current, and
was referred to in the Annual Report of the Council in _February_, 1864,
under the name of "the Astronomer Royal's elaborate investigation, as
exhibited by Mr. Dunkin." Both Mr. Airy and Mr. Dunkin express grave doubts
as to the sufficiency of the data: and, regarding the coincidence of all
the results as highly curious, feel it necessary to wait for calculations
made on better data. The report of the Council states these doubts. Mr.
Reddie, who only published in _September_, 1863, happened to see the Report
of February, 1864, assumes that the doubts were then first expressed, and
declares that his book of September had the triumph of forcing the
Astronomer Royal to abandon the _fact_ of motion of the solar system by the
February following. Had Mr. Reddie, when he saw that the Council were
avowedly describing a memoir presented some time before, taken the
precaution to find out _when_ that memoir was presented, he would perhaps
have seen that doubts of the results obtained, expressed by one astronomer
in March, 1863, and by another in 1859, could not have been due to his
publication of September, 1863. And any one else would have learnt that
neither astronomer doubts the _solar motion_, though both doubt the
sufficiency of present means to determine its _amount_ and _direction_.
This is implied in the omitted words, which Mr. Reddie--whose omission
would have been dishonest if he had seen their meaning--no doubt took for
pleonasm, superfluity, overmuchness. The rashness which pushed him headlong
{350} into the quillet that _his_ thunderbolt had stopped the chariot of
the Sun and knocked the Greenwich Phaeton off the box, is the same which
betrayed him into yet grander error--which deserves the full word,
_quidlibet_--about the _Principia_ of Newton. There has been no change of
opinion at all. When a person undertakes a long investigation, his opinion
is that, at a certain date, there is _prima facie_ ground for thinking a
sound result may be obtained. Should it happen that the investigation ends
in doubt upon the sufficiency o