Page:Popular Science Monthly Volume 5.djvu/274

260 on the whole, we shall find that the number and faintness of the small stars, seen by any astronomer in any one limited region, are a very fair test of his own assiduity, and of the excellence of his telescope.

It will be seen that Le Gentil has made of the star θ Orionis four stars, adding one to the number seen by Huyghens. These four are the celebrated trapezium of Orion, and they constitute one of the most remarkable multiple stars of the whole heavens.



Messier, who examined the nebula carefully, in 1771, gives these four stars, and a very good drawing of the nebula, in "Histoire de l'Académie," 1771. This work was extremely creditable, considering his instrumental means, and the comparatively short time spent upon it.

This trapezium was destined to become famous, for, in 1826, the elder Struve found, close to one of the large stars of the trapezium, a small companion—the "fifth star." This was for a long time considered as a delicate test for an instrument; but, in December, 1832, Herschel found yet another small star—the "sixth star." The trapezium now was seen (with suitable means) as in Fig. 3.

Let us follow the history of the whole nebula for a time, and we shall see what additions have been made to our knowledge of the space near this remarkable group.

It may be here remarked that the grouping of these six stars is in all probability not accidental, but that they are physically connected: Struve has shown that the chances are 9,000 to one against any two