The morning call. [volume] (San Francisco [Calif.]) 1878-1895, 1891-12-20

star on the finest observing nights with the
great 36-nch Lick telescope, the most pow
erful in the world; but now it can be seen
that the star is slightly elongated instead of
being perfectly round. 1t is quite impossi-
bic even with that great telescope to see the
separate stars. With a large telescope the
powers used in measuring such close doubles
are very high indeed, the limit being about
100 diameters to the inch of aperture. Mr..
Burnham, who does all the double-star work
at the Lick Observatory, and who is the
ablest double-Star observer that has ever
lived. says, in relation to the magnifying
powers used with the 36-inch telescope:
The mlerOmeter eyepieces give powers
approximately OF 450, go. 1000. 1850, 1000,
POO and $500 diameters. For very close
pairs the last three are generally used when
the air is sufficiently steady In measuring
very unequal pairs with distances of IL
seconds Of arc and upward, the two lower
powers have been usually employed" At
the University of Virginia the highest
power used with the 26-inch telescope is
$500 diameters
We were favored with a view of the
pleiadeS, and then the telescope was direct
ed successfully to two star clusters in
the Il. com, constellation Of Aurlga: The first
especial beauty, but the second well
merits the enthusiastic description by
Admiral Smyth (who used a telescope
OF only inches aperture). lie descr bes it
as "a magnificent object; the whole field of
view being as it were strewn with spark
ling gold dust, and the group is receivable
into about 800 rather faint stars. besides
the outlers." The Rev. T. w. Webb, au-
thor of Celestial Objects for Common
telescopes. the amateur astronomers
bible, says it is, even in smaller iEstru-
ments. extremely beautiful, and one of the
finest of its class" AS star cluster ap-
pears nearly twice as bright in the Chabot
telescope as in a 6-inch telescope, one can
imagine how glorious was the view we had
of it In fact some of the party considered
1t the finest thing seen during the evening.
The next object viewed was the great
nebula in Orion. As this is something that
almost any one who has ever looked through
telescope at all has SEEM and which peu-
pie invariably consider either about the
finest thing they ever saw or else not worth
looking at, description OF it would hardly
be worth the while.
The last object viewed was the star cluster
in Gemini, or the Twins, and which stands
pre-eminent as the finest among the star
clusters. The whole telescope field of view,
subtending an angle of As degrees to the
eye, appeared filed with hundreds of fash
ing suns, presenting scene of Incompatible
splendor and sublimity. The Rev. T. w.
Webb, who used telescope of little less
than 4 inches aperture, calls it "a beauti-
full and striking region of small stars,
nebula to the naked eye" How differently
LasselPs 24-inch reflector showed it his
own words will best tell. "a marvellously
striking object-no one can see it for the
first time without an exclamaton-the field
of view 49, in diameter and subtending an
angle of 1919 to the eye, is perfectly full of
brilliant stars, unusually equal in magn-
tude and distribution over the entire
area. Nothing but sight of the OBJ.
Ject itself can convey an adequate
idea of its exquisite beauty" From the
small stars being inclined to form curves of
three OIL four. and often with large one at
the root of the curve, it somewhat reminds
one OF the bursting of a sky-rocket.
In conclusion. will advise any one who
visits an observatory, aud who is disap-
pointed in what he sees, who thinks the
star clusters and nebul8 very small and in
significant things after all, to look with both
eyes open and to endeavor to compare the
size of the field of view with that of the sky
itself He will see that the field that look ed
so small to him would really. if placed in
the sky, extend half way from horizon to
zenith, and that the stars composing a
cluster, which looked so insignificant to
him, are really brighter than Sirius.