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as "Plus, small" I have given velocities of plus 100 km / sec; and N. G. C. 5195, whose velocity he gives as "Small," I have given a velocity of zero. I do not know whether his velocities are corrected for solar motion or not, but the corrections would be comparatively insignificant, so that makes no difference in the results.

The list may now be solved out by least squares in the usual way, such as is described, for instance, in Campbell's "Stellar Motions," p. 170, and one obtains as the components of velocity of the center of position of the group:

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where, of course, x is in R. A. 0h 0m, Dec. 0°, y in R. A. 6h Dec. 0°, and z is at the north pole.

It appears that the ratios of the quantities determined to their probable errors are 2.3, 1.7, and 1.2, respectively, which is quite encouraging, and, I think, points quite strongly to the reality of the results.

The direction determined by the above quantities is the apex of the nebulas' motion, and the antapex of our motion. It turns out, according to this, that our nebula is moving with a velocity of 670 km/sec in the direction of R. A. 20 hrs. Dec. -20°. This is a point between Sagittarius and Capricorn, about 60 degrees from Pickering's pole of the Galaxy, and while that does not come as near being in the plane of the Galaxy as might be desired, yet it comes as close as could reasonably be expected from a first trial. One wonders whether there is not something in Slipher's conjecture that the spiral nebulae move edgewise.

I think the determination of radial velocities of spiral nebulae should be vigorously pursued, in order to quickly find out whether the above results are indeed real.

University of Iowa.
Dec. 30, 1915.

THE STARRY SICKLE.

Where Leo waits King Sol in dog-days' reign
And Regulus shines diamond-like and bright,
When springtime wakes and summer smiles again
Till harvest moon beams mellow in the night;
Six suns, with four stars sparkling in its train,
Like question-mark which faces to the right.
Or secret symbol written clear and plain,
A starry sickle glttters in men's sight.

CHARLES NEVERS HOLMES.

Hotel Nottingham, Boston.

PLANET NOTES FOR MARCH, 1916.

The sun will move from 7° 36′ south of the equator to 4° 8' north of the equator during the month of March. It will cross the equator on March 20. At the time of crossing the equator the right ascension of the sun will be 0h 0m 0, as this is the point from which right ascension is measured. This is the date of the vernal equinox, the date of the beginning of spring.

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The moon will be at its farthest point from the earth for the month on March 12, and nearest on March 26.

Mercury will be at a point of greatest elongation west of the sun on the first day of the month. It will then be visible in the morning sky. It will be visible during the greater part of the month but will gradually be approaching the sun.

Venus will continue to be the brilliant and conspicuous object in the evening sky throughout the month. It will be a few degrees north and two and a half hours east of the sun. It will be approaching the earth throughout the month. Its average distance from the earth for the month will be about the mean distance from the earth to the sun.

Mars, having just passed a point of opposition, will be favorably situated during this month. It will cross the meridian about nine o'clock in the evening. It will however again be receding from the earth.

Jupiter will scarcely be within reach of observation at all during March. It will be found low in the twilight at sunset at the beginning of the month, and about the middle of the month will be lost in the rays of the sun.

Saturn will be moving westward at the beginning of the month but will turn and move eastward on March 12. It will be in quadrature with the sun, 90° east, on March 30. It will therefore be on the meridian about sunset.

Uranus will be visible in the early morning. It will rise a few hours before the sun.

Neptune will be a short distance northeast of Saturn. It will also therefore be favorably situated for observation. It will have retrograde motion during this month.

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Saturn's Satellites for March, 1916—Continued.

II. Enceladus. Period 1d 8h.9.

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Apparent Orbits of the Seven Inner Satellites of Saturn, at date of
Opposition, January 4, 1916, as seen in an Inverting Telescope.

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VARIABLE STARS.

Approximate Magnitudes of Variable Stars of Long Period on Jan. 1, 1916.

[Communicated by the Director of Harvard College Observatory, Cambridge, Mass.]

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