Here, however, we are met with the positive assertion that there is a very small star (of about the sixth magnitude) in the south, called
Sigma Octantis, round which all the constellations of the south revolve, and which is therefore the southern polar star. It is scarcely polite to contradict the statements made, but it is certain that persons who have been educated to believe that the earth is a globe, going to the southern parts of the earth do not examine such matters critically. They see the stars move from towards the east towards the west, and they are satisfied. But they have not instituted special experiments, regardless of results, to ascertain the real and absolute movements of the southern constellations. Another thing is certain, that from and within the equator the north pole star, and the constellations
Ursa Major,
Ursa Minor, and many others, can be seen from every meridian simultaneously; whereas in the south, from the equator, neither the so-called south pole star, nor the remarkable constellation of the
Southern Cross, can be seen simultaneously from every meridian, showing that all the constellations of the south--pole star included--sweep over a great southern arc and across the meridian, from their rise in the evening to their setting in the morning. But if the earth is a globe,
Sigma Octantis a south pole star, and the
Southern Cross a southern circumpolar constellation, they would all be visible at the same time from every longitude on the same latitude, as is the case with the northern pole star and the northern circumpolar constellations. Such, however, is strangely not the case;
Sir James Clarke Ross did not see it until he was 8° south of the equator, and in longitude 30° W.
MM. Von Spix and Karl Von Martius, in their account of -their scientific travels in Brazil, in 1817-1820, relate that "on the 15th of June, in latitude 14° S, we beheld, for the first time, that glorious constellation of the southern heavens, the Cross, which is to navigators a token of peace, and, according to its position, indicates the hours of the night. We had long wished for this constellation as a guide to the other hemisphere; we therefore felt inexpressible pleasure when we perceived it in the resplendent firmament."The great traveller
Humboldt says:--
"We saw distinctly, for the first time, the cross of the south, on the nights of the 4th and 5th of July, in the 16th degree of latitude. It was strongly inclined, and appeared from time to time between the clouds. . . . The pleasure felt on discovering the Southern Cross was warmly shared in by such of the crew as had lived in the colonies."
If the Southern Cross is a circumpolar cluster of stars, it is a matter of absolute certainty that it could never be in-visible to navigators upon or south of the equator. It would always be seen far above the horizon, just as the "Great Bear" is at all times visible upon and north of the equator. More especially ought it to be at all times visible when the nearest star belonging to it is considerably nearer to the so-called "pole star of the south" than is the nearest of the stars in the "Great Bear" to the pole star of the north.
Humboldt did not see the
Southern Cross until he was in the 16th latitude south, and then it was "strongly inclined," showing that it was rising in the east, and sharing in the general sweep of the stars from east to west, in common with the whole firmament of stars moving round the pole star of the northern region.
We have seen that wherever the motions of the stars are carefully examined, it is found that all are connected, and move in relation to the northern centre of the earth.
There is nowhere to be found a "break" in the general connection. Except, indeed, what is called the "proper motion" of certain stars and groups of stars all move in the same general direction, concentric with the north pole, and with velocities increasing with radial distance from it.
The
Southern Cross is not at all times visible from every point of the southern hemisphere, as the
"Great Bear" is from every point in the northern, and as both must necessarily and equally be visible if the earth is globular. In reference to the several cases adduced of the
Southern Cross not being visible until the observers had arrived in latitudes 8°, 14°, and 16° south, it cannot be said that they might not have cared to look for it, because we are assured that they "had long wished for it," and therefore must have been strictly on the look out as they advanced southwards. And when the traveller
Humboldt saw it
"the first time" it was
"strongly inclined," and therefore low down on the eastern horizon, and therefore previously invisible, simply because it had not yet risen.
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