Midway between the Southern Cross and the False Cross there is a nebula visible to the naked eye, and in it once shone a bright star. When Halley was observing in the southern hemisphere towards the end of the seventeenth century, he catalogued it as of fourth magnitude, but Lacaille and later astronomers marked it as second. Sir John Herschel first saw it in 1834, when he was at the Cape, and he says that it remained steady for three years, from 1834 to 1837. On the 16th of December 1837 he began his observations as usual by noting the brightest stars in the heavens and arranging them in order on a list, when to his astonishment he saw “a new candidate for distinction among the very brightest stars of first magnitude” in a part of the sky where he was quite sure no such brilliant object had been seen before. He consulted a map and satisfied himself that it was his “old friend Eta Argūs,” but nearly three times as bright as usual. He made careful comparisons with other bright stars then visible, and says that “Fomalhaut and Alpha Gruis were at the time not quite so high, and Alpha Crucis much lower, but all were fine and clear, and Eta Argūs would not bear to be lowered to their standard.” It was a little brighter than Rigel, and the only stars which outshone it were Sirius and Canopus. Still it grew brighter, for twelve days later it greatly surpassed Rigel and could only be compared with α Centauri. After this the light began to fade, and by April 1838 it was not much brighter than Aldebaran. Herschel now returned to England, and therefore he did not see the still more startling changes of this wonderful star, but he has recorded what he heard from others. In March 1843 it became much brighter than Rigel or α Centauri, but its light wavered, and he says: “We have here an epoch of great interest, a temporary minimum, with a kind of trepidation or fluttering of light, followed, however, by another step in advance even yet more extraordinary.” This was in the following month, April 1843, when Eta became almost equal to Sirius, the brightest of all stars. It was the highest point reached by this extraordinary star, and two years later Maclear at the Cape wrote to the Astronomer-Royal in England: “When you see Sir John Herschel again, tell him that Eta Argūs has been for some time rather larger than Canopus, and seems again on the decline.” Sir John’s concluding remarks seem to indicate something of pained surprise that a star could behave in so erratic and unaccountable a fashion: “A strange field of speculation is opened by this phenomenon. Here we have a star fitfully variable to an astonishing extent, and whose fluctuations extend over centuries.... What origin are we to ascribe to these sudden flashes and relapses? What conclusions are we to draw as to the comfort or habitability of a system depending for its supply of light and heat on so uncertain a source?”