The star finder shown in the picture was invented by Dr. C. J. Kullmer, of Syracuse, N. Y., and has been highly praised by many great astronomers.
Fig. 186.—Kullmer Star Finder.
You should own one if possible, for you do not need to know anything about the stars to operate it. It is mounted on the principle of a big telescope, but it is a naked eye instrument, an arrow taking the place of the telescope.
The finder is placed on a table, or other level surface, with the dial facing north. Then the pointer and dial are set for the day and hour when you want to find the position in the sky of a certain constellation. The indicator is turned to the name of the constellation on the dial, and this also tells the direction to set the arrow.
This is all there is to it and the arrow points right at the group of stars you want, whether they are above the horizon or not.
The finder can be used for many purposes, and it is a wonderful aid in making out in the sky the path of the stars, Sun, Moon and planets, and when they rise and set. In fact, it is a complete observatory on a small scale. Its cost is only $5.00.
APPENDIX N
THE ELLIS SEASONAL TWILIGHT CHART
A useful chart, designed by Miss E. Rebecca Ellis, of Wellesley College, Wellesley, Mass. It makes clear the changes in the lengths of the day, the phenomena of the seasons, etc. Its price is $1.00.