That may serve as an illustration of the lesson that a man had better say as little as possible concerning anything of which he knows only a little; and that is a lesson which many people need to learn. For instance, there are probably more works on the Book of Revelation than upon any other part of the Scriptures, and, with the exception of just a few, they are not worth the paper on which they are printed. Then, next to the Book of Revelation, in this respect, is the Book of Daniel; and because it is so difficult to explain, many men have written upon it, but as a rule the result of their writing has been that they have only confuted and contradicted one another. Let us, brethren, preach what we know, and say nothing of that of which we are ignorant. * * * * * We have gone a long way, in imagination, in traveling to the planet Uranus; but we have not yet completed our afternoon's journey. It was observed by certain astronomers that the orbit of Uranus sometimes deviated from the course they had marked in their chart of the heavens; and this convinced them that there was another planetary body, not then discovered, which was exerting an unseen but powerful influence upon Uranus. This fact, that these huge worlds, with so many millions of miles of space between them, do retard or accelerate one another's movements, is to me a beautiful illustration of the influence that you and I have upon our fellowmen. Whether consciously or unconsciously, we either impede a man's progress in the path that leads to God, or else we quicken his march along the heavenward way. "None of us liveth to himself." The astronomers came to the conclusion that there must be another planet, previously unknown to them, that was disturbing the motion of Uranus. Unknown to each other, an Englishman, Mr. Adams, of Cambridge, and a Frenchman, M. Leverrier, set to work to find out the position in which they expected the heavenly body to be discovered, and their calculations brought them to almost identical results. When the telescopes were pointed to that part of the heavens where the mathematical astronomers believed the planet would be found, it was at once discovered, shining with a pale and yellow light, and we now know it by the name of NEPTUNE.