How could Jacob have known, except by revelation, that the vast continent which the Nephites inhabited was entirely surrounded by the waters of the great oceans? He and his companions had, but a few short years before, first landed on its shores, and had now explored but a very small portion of its wide extent, and there were no others in communication with them who could supply the information that North and South America were one immense island. Evidently the Lord had revealed this fact to them. And, by the way, this simple statement is strong testimony of the divine authenticity of the Book of Mormon. At the time that this portion of the sacred plates was translated (A. D. 1827-8), or even when the whole book was published and the Church of Jesus Christ was organized (A. D. 1830), it was not known to modern science that the American continent was indeed an island. Joseph Smith could not have received knowledge of this fact, so unhesitatingly affirmed, from any learned geographer or practical navigator. The hope of centuries, in Europe, had been to discover a north-west passage to India, but to that date all attempts had met with disastrous failure, so far as the chief object was concerned. Little or nothing was then known of the North American coast, west of Hudson's Bay. It was not until, after repeated expeditions, that in May, 1847, the truth of the statement of Jacob could be affirmed from actual knowledge of the geographical features of the country, as at that date the explorations and surveys by land and sea, from east and west, were brought sufficiently near to leave the matter without a doubt. It was not until 1854 that the first ship's crew (that of Captain McClure), which ever sailed across the Arctic Ocean from the Pacific to the Atlantic, along the northern coast of America, returned from their perilous voyage. We thus find that human geographical knowledge could not have aided the prophet Joseph Smith in making this statement, had it originated with him and not with the son of Lehi.
While ancient Greek and other philosophers were groping among the fallacies of the absurd system of astronomy given to the world by Ptolemy, and teaching that the sun with all the stars revolved around the earth, the Nephites were in possession of the true knowledge with regard to the heavenly bodies, etc. Possibly they were the only people of their age blessed with a comprehension of these sublime truths. It is altogether probable that among their scriptures were copies of the Book of Abraham, from which they could acquaint themselves with the beauties and harmonies of celestial mechanism. They undoubtedly had the writings of Joseph, the son of Jacob, as these are quoted in the Book of Mormon; and, as the prophet Joseph Smith found the writings of Abraham and Joseph together in the Egyptian mummies, it is far from improbable that the Nephites, as well as the early Egyptians, possessed both. To show the astronomical knowledge possessed by the Nephites, we will draw attention to the words of two of their prophets. The first extract is from the reply of Alma to Korihor, the Anti-Christ (B. C. 75), when the latter asked for a sign to prove the existence of a God. His words are: Thou hast had signs enough; will ye tempt your God? Will ye say, Show unto me a sign, when ye have the testimony of all these thy brethren, and also all the holy prophets? The scriptures are laid before thee, yea, and all things denote there is a God; yea, even the earth, and all things that are upon the face of it, yea, and its motion; yea, and also all the planets which move in their regular form, doth witness that there is a Supreme Creator. The next quotation is from the reflections of one of the servants of God (probably Mormon) inserted into the Nephite history of about seventy years later. The writer is speaking of the greatness and goodness of God, and among other things declares: Yea, by the power of his voice doth the whole earth shake; yea, by the power of his voice doth the foundations rock, even to the very center; yea, and if he say unto the earth, move it, it is moved; yea, if he say unto the earth, thou shalt go back, that it lengthen out the day for many hours, it is done; and thus according to his word, the earth goeth back; and it appeareth unto man that the sun standeth still; yea, and behold, this is so; for sure it is the earth that moveth, and not the sun. Thus we find that in these points, the astronomical knowledge of the Nephites was, at least equal to that of the moderns.