, forty-one thousand
years, for the time, (the space being our own distance from the sun
repeated six hundred and seventy thousand times,) what would be the
time required for reaching, in the _body_, that distance to which
Lord Rosse's six feet mirror has so recently extended our
_vision_. The time would be, as Dr. Nichol computes, about two
hundred and fifty millions of years, supposing that our rate of
travelling was about three times that of our earth in its orbit. Now,
as the velocity is assumed to be the same in both cases, the ratio
between the distance (already so tremendous) of Bessel's 61
_Cygni_, and that of Lord Rosse's farthest frontier, is as forty-
one thousand to two hundred and fifty millions. This is a simple rule-
of-three problem for a child. And the answer to it will, perhaps,
convey the simplest expression of the superhuman power lodged in the
new telescope:--as is the ratio of forty-one thousand to two hundred
and fifty million, so is the ratio of our own distance from the sun
multiplied by six hundred and seventy thousand, to the outermost limit
of Lord Rosse's sidereal vision.]
Another class, and a frequent one, of equivocal phenomena, phenomena
that are reconcilable indifferently with either of two assumptions,
though less plausibly reconciled with the one than with the other,
concerns the position of stars that seem connected with each other by
systematic relations, and which yet _may_ lie in very different
depths of space, being brought into seeming connection only by the
human eye.
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