Page:Sir William Herschel, his life and works (1881).djvu/181

Rh = 19h 41m, N. P. D. = 74° 33′, number of stars per field = 588; and R. A. = 6h 10m, N. P. D. = 113° 4′, number of stars = 1.1.

The number of stars in certain portions is very great. For example, in the Milky Way, near Orion, six fields of view promiscuously taken gave 110, 60, 70, 90, 70, and 74 stars each, or a mean of 79 stars per field. The most vacant space in this neighborhood gave 60 stars. So that as sweeps were two degrees wide in declination, in one hour (15°) there would pass through the field of his telescope 40,000 or more stars. In some of the sweeps this number was as great as 116,000 stars in a quarter of an hour.

When first applied his telescope to the Milky Way, he believed that it completely resolved the whole whitish appearance into small stars. This conclusion he subsequently modified. He says:

"It is very probable that the great stratum called the Milky Way is that in which the sun is placed, though perhaps not in the very centre of its thickness.

"We gather this from the appearance of the Galaxy, which seems to encompass the whole heavens, as it