after three seconds lull, a renewed swaying motion lasted four to five seconds. A second quake occurred at 4 a.m., less violent, and lasted 30 seconds.

Van Anda, Texada Island, Wm. Kirkness (125 miles E.)-Felt by those awake, caused a rocking movement and rattling of furniture and windows. Not felt by observer, who was travelling on a road near Van Anda at the time; duration about 40 seconds.

LOWER MAINLAND

Vancouver, T. S. H. Shearmen (185 miles E.)-Four or five shocks were reported; possibly 1 minute and 15 seconds covered duration of these, direction from the westward. The noise resembled the rumbling of a distant automobile or sudden gust of wind. Clocks were stopped in some cases. The master clock of the Vancouver Block (the tallest building in the city) stopped at 00:41, while a iarge clock on the main floor of the Post Office stopped 00:45:46 sec. Possibly the great height of the Vancouver Block clock would cause it to stop during one of the faint preliminary shocks. The regulator clock at Messrs. Henry Birks stopped at 00:43:10 sec., and was not one second in error. This clock is thirty feet above the ground level, and near the Vancouver Block. Loose articles were thrown from shelves, etc.

Chilliwack, J. H. Chapman (240 miles E.)-Very light quake felt by a few; no damage.

Kelowna, George R. Binger (355 miles E.)-Heard a curious noise as he was writing at 00:40 a.m. on the 6th; this continued, and aroused his wife, who also heard it, but no tremor was felt. Other people heard this noise and several clocks were stopped. At the C.P.R. wharf the express agent felt the building sway and the files on the walls oscillated. He also heard the noise. The wharf is built on piles.

From the above information this quake appears to have been felt within a radius of about 300 miles, very slight along the Lower Fraser Valley, and if the Kelowna time is incorrect the seismic waves appear to have become accentuated in the Okanagan Lake District. It is possible, however, that a slight local quake may have occurred there a few minutes before the Vancouver Island seismic waves could reach that district. It is interesting to note that this quake was not felt to any marked degree in parts of the Southern and eastern sections of Vancouver Island, while at the City of Vancouver on the mainland the effect

appears to have been more pronounced, as is shown by the number of clocks stopped there, and at New Westminster and other adjacent parts of the Fraser River Valley the quake was scarcely noticed. It is also curious that the clock in the high Vancouver Block should have stopped only three seconds after the quake occurred on the west coast, the time at point of origin being 8.40.57 G.M.T. Though assured the time of this clock was correct, measurements show that the first tremors would reach the Vancouver Block only a few seconds before they were recorded on the Victoria seismograph at 8.41.44, and the first surface waves at 8.42.00, the earliest time one might expect this high tower clock to stop.

METEOROLOGICAL OBSERVATORY, GONZALES HEIGHTS OBSERVATORY,

Victoria, B.C.

F. NAPIER DENISON.

ASTRONOMICAL NOTES

[The paper by Dr. Shapley from which this extract is taken supports the view that our galactic system includes all the visible Universe; in other words, he opposes the island universe" hypothesis.--C. A. C.]

THE ARRANGEMENT OF THE SIDEREAL UNIVERSE. -A fairly definite conception of the arrangement of the sidereal system evolves naturally from the observational work discussed in the preceding Contributions. We find, in short, that globular clusters, though extensive and massive structures, are but subordinate items in the immensely greater organization which is dimly outlined by their positions. From the new point of view our galactic universe appears as a single, enormous, all-comprehending unit, the extent and form of which seems to be indicated through the dimensions of the widely extended assemblage of globular clusters. The fundamental nature of the galactic plane, in the dynamical structure of all that we now recognize as the sidereal universe, is manifested by the distribution of clusters in space. Near this plane lie the celestial objects that we customarily study. The open clusters, the diffused and planetary nebulæ, the naked eye stars, most variables, the objects that define and compose the star streams-all of these appear to be far within a relatively narrow equatorial region of the greater galactic system, a region in which such forces are at play that compact clusters of great mass apparently cannot form or exist. The Orion nebula and even the Magellanic clouds are miniature organizations in this general scheme, and undoubtedly are dependents of the galaxy.

The adoption of such an arrangement of sidereal objects leaves us with no evidence of a plurality of stellar "universes." Even the remotest of recorded globular clusters do not seem to be independent organizations. The hypothesis that spiral nebulæ are separate galactic systems now meets with further difficulties. So long as the high velocities of nebula were unapproached by the

motions of other objects and the maximum luminosity attainable by stars was beyond estimate, and so long as the diameter of the galactic system was thought to be only a thousand light-years or so, we had a fairly plausible case for the "island universe" hypothesis. But now we must consider radial velocities of several hundred kilometers a second as quite possible for objects in our own system; we must assume a moderate upper limit of luminosity, perhaps even for the most massive of novæ; and any external "universe”, must now be compared with a galactic system probably more than three hundred thousand light-years in diameter. As seen from the centre of the galactic system, globular clusters would be distributed in the sky much as the spirals are when observed from the earth.

It is probable that the further accumulation of observations will modify to some extent the views outlined above and discussed more fully in the following pages. The present data may in some cases be susceptible of alternative interpretation, or possibly the conclusions may be questioned in the belief that the material is insufficient. But the greater part of the hypothesis proposed is merely the most direct and simple reading of recent observations.

The suggested plan of the galactic system may be concretely formulated through the following series of propositions; some of them are later amplified in so far as seems necessary; for others the discussion of preceding contributions will suffice. A few of the statements are obvious corollaries, while those designated B and F, in some of their details, may be less easy to maintain. Taken altogether they attempt to establish a general idea of the arrangement, extent, and constituency of the system of stars and nebulæ. A. The globular clusters are a part of the galactic system and knowledge of their distances seems at present to afford the best way to fathom the system.

B. The system of globular clusters, which is coincident in general, if not in detail, with the sidereal arrangement as a whole, appears to be somewhat ellipsoidal. The longest axis of the ellipsoid lies in the galactic plane and passes the sun at a distance of approximately three thousand parsecs. Its nearest point is in galactic longitude 240°, nearly coincident with the direction of

the centre assigned to the local system of stars.

C. The centre of the sidereal system is distant from the earth some twenty thousand parsecs in the direction of the constellation Sagittarius; it lies in the galactic plane, which dynamically and statistically appears to be the symmetrical plane of the entire sidereal universe as now known. As seen from the sun the thinnest part of the Milky Way lies in Gemini, Taurus, and Auriga-a region rich in bright open clusters close to the galactic plane.

D. The axes of the system in the galactic plane and perpendicular to it may not differ greatly; but the gravitationally important equatorial segment, which apparently contains most of the stars, is at least thirty times as extended in the plane as at right angles thereto.

E. The equatorial region appears to be uninhabitable by compact systems, such as globular clusters, notwithstanding the greater abundance there are of stellar material.

F. The stars in the neighborhood of the sun (practically all that go into our catalogues of spectrum, position and motion) appear to compose (1) a large, open, moving subordinate group, and (2) a part of the surrounding and interpenetrating star fields of the equatorial segment of the greater galactic system. The centre of the local system is in the direction of the constellation Carina, nearly at right angles to the direction of the centre of the general galactic system, but less than one two-hundredths as far away. The plane of symmetry and condensation of the local cluster is inclined to the galactic plane about 12°; the centre of the cluster is north of the galactic plane, and the sun is north of both planes.

G. The volume of space occupied by stars brighter than the sixth apparent magnitude, some of which, being absolutely very bright, are extremely distant as compared with the majority of naked-eye stars, is at most only a hundred-thousandth of the volume occupied by the other parts of the galactic system.

In order to show where the earlier working hypotheses stand with respect to the interpretation now offered, it may be of interest to note the development, during the course of this work on