The values of (αδ), _m_, _Sp_ are taken from H. 50. The values of _l_, _b_ are computed from (αδ) with the help of tables in preparation at the Lund Observatory, or from the original to plate I at the end, allowing the conversion of the equatorial coordinates into galactic ones. The values of π are generally taken from the table of KAPTEYN and WEERSMA mentioned in the previous chapter. The values of μ are obtained from B. P. C., those of the radial velocity (_W_) from the card catalogue in Lund already described. There are in all, in the sky, 20 stars having an apparent magnitude brighter than 1m.5. The brightest of them is _Sirius_, which, owing to its brilliancy and position, is visible to the whole civilized world. It has a spectrum of the type A0 and hence a colour-index nearly equal to 0.0 (observations in Harvard give _c_ = +0.06). Its apparent magnitude is -1m.6, nearly the same as that of Mars in his opposition. Its absolute magnitude is -0m.3, _i.e._, fainter than the apparent magnitude, from which we may conclude that it has a distance from us smaller than one siriometer. We find, indeed, from the eighth column that _r_ = 0.5 sir. The proper motion of Sirius is 1″.32 per year, which is rather large but still not among the largest proper motions as will be seen below. From the 11th column we find that Sirius is moving towards us with a velocity of 1.6 sir./st. (= 7.6 km./sec.), a rather small velocity. The third column shows that its right ascension is 6h 40m and its declination -16°. It lies in the square GD_7 and its galactic coordinates are seen in the 5th and 6th columns.