29. Q. What are some of the amazing discoveries made by the
spectroscope within a few years? A. In chemistry it reveals substances
never known before. It tells the chemical constitution of the sun, the
movements taking place, the nature of comets, and nebulæ.
30. Q. By the spectroscope what do we know of the atmospheres of some
of the other planets? A. We know that the atmospheres of Venus and Mars
are like our own, and that those of Jupiter and Saturn are very unlike.