and often much poetry in his Wisdom of the Ancients.  Towards the end of his life he began to embody his thoughts and plans in a philosophical tale, which he did not finish—­the New Atlantis—­a charming example of his graceful fancy and of his power of easy and natural story-telling.  Between the Advancement and the Novum Organum (1605-20) much underground work had been done.  “He had finally (about 1607) settled the plan of the Great Instauration, and began to call it by that name.”  The plan, first in three or four divisions, had been finally digested into six.  Vague outlines had become definite and clear.  Distinct portions had been worked out.  Various modes of treatment had been tried, abandoned, modified.  Prefaces were written to give the sketch and purpose of chapters not yet composed.  The Novum Organum had been written and rewritten twelve times over.  Bacon kept his papers, and we can trace in the unused portion of those left behind him much of the progress of his work, and the shapes which much of it went through.  The Advancement itself is the filling-out and perfecting of what is found in germ, meagre and rudimentary, in a Discourse in Praise of Knowledge, written in the days of Elizabeth, and in some Latin chapters of an early date, the Cogitationes de Scientia Humana, on the limits and use of knowledge, and on the relation of natural history to natural philosophy.  These early essays, with much of the same characteristic illustration, and many of the favourite images and maxims and texts and phrases, which continue to appear in his writings to the end, contain the thoughts of a man long accustomed to meditate and to see his way on the new aspects of knowledge opening upon him.  And before the Advancement he had already tried his hand on a work intended to be in two books, which Mr. Ellis describes as a “great work on the Interpretation of Nature,” the “earliest type of the Instauratio,” and which Bacon called by the enigmatical name of Valerius Terminus.  In it, as in a second draft, which in its turn was superseded by the Advancement, the line of thought of the Latin Cogitationes reappears, expanded and more carefully ordered; it contains also the first sketch of his certain and infallible method for what he calls the “freeing of the direction” in the search after Truth, and the first indications of the four classes of “Idols” which were to be so memorable a portion of Bacon’s teaching.  And between the Advancement and the Novum Organum at least one unpublished treatise of great interest intervened, the Visa et Cogitata, on which he was long employed, and which he brought to a finished shape, fit to be submitted to his friends and critics, Sir Thomas Bodley and Bishop Andrewes.  It is spoken of as a book to be “imparted sicut videbitur,” in the review which he made of his life and objects soon after he was made Solicitor