PREFACE TO PART I. 



THE Manuscripts left by Professor John Couch Adams were a mass of 

 notes, studies, and rough work, the accumulation of his lifetime. What they 

 contained was not known, but anyone familiar with his published work could 

 recall more than one occasion when chance drew from him an unexpected 

 description of results or researches of which it seemed we might otherwise 

 never have heard. Hence it seemed right to examine the stove from which 

 these were drawn so that fresh matter of interest should not needlessly 

 be lost. 



The result of this search is contained in the following pages, of 

 which lecture courses and elucidations of his published work form the 

 greater part. 



It is clear that he had not kept unpublished any completed work of 

 great importance ; yet these extracts may be read with interest for many 

 reasons : some he had himself promised to publish at a convenient time ; 

 others contain the methods of investigations of which he has merely stated 

 the results ; and others, again, though fragmentary, are significant, because 

 they indicate the plan he approved for attacking certain large problems. 



The papers, as they reached me, and indeed as Adams left them, 

 were almost devoid of arrangement, except that they were folded in parcels 

 of a few pages each, the product of a day's or a few days' sitting ; each 

 parcel was generally very clear in itself, but carried no indication of its 

 purpose or relations to others. It would have been a hopeless task to 

 discover whether such a mass contained matter of value had not almost 

 every page been dated. This permitted reference to a diary, which was 

 sometimes very useful, though it was often silent at his most active 

 seasons. 



As a guide in the lecture courses I had notes taken by Mr A. Graham 

 of Cambridge Observatory, by the late Rev. A. Freeman, by myself, and 

 by others, which were of considerable value. But in most cases the purpose 



