Perhaps some of those curious persons whose successors now devote so much labour to double acrostics may have pondered on this renowned cryptograph, and even attempted to decipher it. But even if such attempts were made, we do not learn that they were successful. A few years of further study were thus secured to Huyghens. He tested his theory in every way that he could devise, and he found it verified in every detail. He therefore thought that it was needless for him any longer to conceal from the world his great discovery, and accordingly in the year 1659--about three years after the appearance of his cryptograph--he announced the interpretation of it. By restoring the letters to their original arrangement the discovery was enunciated in the following words:--"_Annulo cingitur_, _tenui_, _plano_, _nusquam cohaerente_, _ad eclipticam inclinato_," which may be translated into the statement:--"The planet is surrounded by a slender flat ring everywhere distinct from its surface, and inclined to the elliptic." Huyghens was not content with merely demonstrating how fully this assumption explained all the observed phenomena. He submitted it to the further and most delicate test which can be applied to any astronomical theory. He attempted by its aid to make a prediction the fulfilment of which would necessarily give his theory the seal of certainty. From his calculations he saw that the planet would appear circular about July or August in 1671. This anticipation was practically verified, for the ring was seen to vanish in May of that year. No doubt, with our modern calculations founded on long-continued and accurate observation, we are now enabled to make forecasts as to the appearance or the disappearance of Saturn's ring with far greater accuracy; but, remembering the early stage in the history of the planet at which the prediction of Huyghens was made, we must regard its fulfilment as quite sufficient, and as confirming in a satisfactory manner the theory of Saturn and his ring. The ring of Saturn having thus been thoroughly established as a fact in celestial architecture, each generation of astronomers has laboured to find out more and more of its marvellous features. In the frontispiece (Plate I.) we have a view of the planet as seen at the Harvard College Observatory, U.S.A., between July 28th and October 20th, 1872. It has been drawn by the skilful astronomer and artist--Mr. L. Trouvelot--and gives a faithful and beautiful representation of this unique object. Fig. 64 is a drawing of the same object taken on July 2nd, 1894, by Prof. E.E. Barnard, at the Lick Observatory.