So far astronomers are pretty generally agreed, unless it be in the value of the earth's radius used above. In his excellent work, entitled "The Sun," we notice that Professor Young gives 3,962.72 English miles as the "latest and most reliable determination" (page 22), while he seems to use Bessel's value of 3,962.80 in obtaining 92,885,000. This may be because the last named value is still in most general use, though less accurate undoubtedly than that of Clarke. Since the transit of Venus, of 1874, the determination of the solar parallax has not been very much improved. The transit of 1882, so far as known, has given surprisingly discordant results, and probably they will be of very little service in improving our knowledge of the distance of the sun. In the midst of all this uncertainty of late work, in ordinary methods two ways of studying the problem show results almost exactly alike. They are obtained from late improved measures of the velocity of light, and from measures by the heliometer. The parallax from these sources is 8.794". The Brazilian results of transit of Venus for 1882, by Wolf and Andre, recently published, make the parallax 8.808". The American reductions for the last transit are not yet completed. From the above brief statement of results, it seems that the value of the solar parallax is likely to be a trifle under 8.80", rather than above it, making the distance of the sun probably very near 93,000,000 miles. The next most important problem pertaining to the sun is its constitution, which is usually considered under four heads: 1. The central portion, thought to be made up chiefly of intensely heated gases. 2. That part which is seen by the aid of the telescope, called the photosphere, consisting of a "shell of luminous clouds formed by the cooling and condensation of the condensible vapors at the surface where exposed to the cold of outer space." (Young.) 3. Outside of the photosphere is a shallow stratum, called the chromosphere, "composed mainly of uncondensible gases (conspicuously hydrogen) left behind by the formation of the photospheric clouds, and bearing something the same relation to them that the oxygen and nitrogen of our own atmosphere do to our own clouds." (Young.) And--