s difficult to measure it; it has
a phantom-like intangibility--we seem not to be able to bring it under
the laws of science.

"We call the stars garnet and sapphire; but these are, at best, vague
terms. Our language has not terms enough to signify the different
delicate shades; our factories have not the stuff whose hues might make
a chromatic scale for them.

"In this dilemma, we might make a scale of colors from the stars
themselves. We might put at the head of the scale of crimson stars the
one known as Hind's, which is four degrees west of Rigel; we might make
a scale of orange stars, beginning with Betel as orange red; then we
should have

Betelgeuze,
Aldebaran,
ss Ursae Minoris,
Altair and _a_ Canis,
_a_ Lyrae,

the list gradually growing paler and paler, until we come to a Lyrae,
which might be the leader of a host of pale yellow stars, gradually
fading off into white.

"Most of the stars seen with the naked eye are varieties of red, orange,
and yellow. The reds, when seen with a glass, reach to violet or dark
purple. With a glass, there come out other colors: very decided greens,
very delicate blues, browns, grays, and white. If these colors are
almost intangible at best, they are rendered more so by the variations
of the atmosphere, of the eye, and of the glass. But after these are all
accounted for, there is still a real difference. Two stars of the class
known as double stars, that is, so little separated that considerable
optical power is necessary to divide them, show these different tints
very nicely in the same field of the telescope.

"Then there comes in the chance that the colors are complementary; that
the eye, fatigued by a brilliant red in the principal star, gives to the
companion the color which would make up white light. This happens
sometimes; but beyond this the reare innumerable cases of finely
contrasted colors which are not complementary, but which show a real
difference of light in the stars; resulting, perhaps, from
distance,--for some colors travel farther than others, and all colors
differ in their order of march,--perhaps from chemical differences.

"Single blue or green stars are never seen; they are always given as the
smaller companion of a pair.

"Out of several hundred observed by Mr. Bishop, forty-five have small
companions of a bluish, or greenish, or purplish color. Almost all of
these are stars of the eighth to tenth magnitude; only once are both
seen b