Page:The Music of the Spheres.djvu/125

 ous constellations, it is well to keep them connected in some such manner.

In modern days the constellation of Hercules has gained in interest through observations made by the telescope. Unfortunately the ancients were not privileged to see its gayly colored double stars and its marvelously beautiful star cluster. Among the double stars, Young mentions an orange and blue, and a white and emerald green; the Rev. T. W. Webb points out one almost appetizingly attractive in its light apple green and cherry red while Serviss notes some charming combinations—orange and green, pale green and purple, light yellow and pale red—which may be seen with such meager assistance as an opera-glass. Serviss, by the way, has written a whole book on what may be seen in the sky with no greater aid than an opera-glass.

The star cluster in Hercules lies on the west side of the constellation, about one-third of the distance from the north end and not far from the figure of the Northern Crown. To the unaided eye, this cluster looks no more than a glimmering speck of light, but if a powerful telescope is trained upon it, it is resolved into a great cluster of stars. These stars, numbering into the thousands, are so packed together toward the center that they have been described as resembling "ice crystals in a snowball." From such a lovely blaze within the center another observer adds that "sprays of stars reach out in all directions like tendrils of a vine."

The stars counted on a photograph of the Hercules cluster which was taken by the great 60-inch reflector on Mount Wilson, number over 50,000! This telescope resolves even the solid glow of light at the center of the cluster into individual stars.

Sir Robert Ball in "Star-land" gives a good illustration of the appearance of a globular cluster of stars as seen in a large telescope. "I take a pepper-castor and on a sheet of white paper I begin