Mr. Newall has found evidence of the element titanium in the spectrum of Betelgeuse (α Orionis); Mr. Goatcher and Mr. Lunt (of the Cape Observatory) find tin in Antares (and Scorpii). If the latter observation is confirmed it will be the first time this metal has been found in a star's atmosphere.[334] It is a curious fact that Al-Sufi (tenth century) does not mention the star ε Aquilæ, which lies closely north-west of ζ Aquilæ, as it is now quite conspicuous to the naked eye. It was suspected of variation by Sir William Herschel. It was first recorded by Tycho Brahé about 1590, and he called it 3rd magnitude. Bayer also rated it 3, and since his time it has been variously estimated from 3½ to 4. If it was anything like its present brightness (4·21 Harvard) in the tenth century it seems difficult to explain how it could have escaped Al-Sufi's careful scrutiny of the heavens, unless it is variable. Its colour seems reddish to me. Mr. W. T. Lynn has shown--and I think conclusively--that the so-called "new star" of A.D. 389 (which is said to have appeared near Altair in the Eagle) was really a comet.[335] Near the place of Tycho Brahé's great new star of 1572 (the "Pilgrim Star"), Hind and W. E. Plummer observed a small star (No. 129 of d'Arrest's catalogue of the region) which seemed to show small fluctuations of light, which "scarcely include a whole magnitude." This may possibly be identical with Tycho Brahé's wonderful star, and should be watched by observers. The place of this small star is (for 1865) R.A. 0{h} 17{m} 18{s}, N.P.D. 26° 37'·1. The region was examined by Prof. Burnham in 1890 with the 36-inch telescope of the Lick Observatory. "None of the faint stars near the place presented any peculiarity worthy of remark, but three double stars were found."[336] With reference to the famous Nova (T) Coronæ--the "Blaze Star" of 1866--Prof. Barnard finds from careful comparisons with small stars in its vicinity that "the Nova is now essentially of the same brightness it was before the outburst of 1866 ... there seems to be no indication of motion in the _Nova_." With reference to the cause of "temporary" stars, or _novæ_, as they are now called by astronomers--the late Prof. H. C. Vogel said--