*** The 'Half-Hours' are filled with clear and agreeable descriptions, whilst eight plates, executed with the most beautiful minuteness and sharpness, exhibit no less than 250 objects with the utmost attainable distinctness."-- _Critic_.
HALF-HOURS WITH THE TELESCOPE: Being a popular Guide to the Use of the Telescope as a means of Amusement and Instruction.

Adapted to inexpensive instruments.

By R.
A.PROCTOR, B.A., F.R.A.S.

12mo, cloth, with illustrations on stone and wood.

Price, $1.25.
"It is crammed with starry plates on wood and stone, and among the celestial phenomena described or figured, by far the larger number may be profitably examined with small telescopes."-- _Illustrated Times._ HALF-HOURS WITH THE STARS: A Plain and Easy Guide to the Knowledge of the Constellations, showing in 12 Maps, the Position of the Principal Star-Groups Night after Night throughout the Year, with introduction and a separate explanation of each Map.