These two engagements are fortuitous, and depending upon others; the one is troublesome by its rarity, the other withers with age, so that they could never have been sufficient for the business of my life.  That of books, which is the third, is much more certain, and much more our own.  It yields all other advantages to the two first, but has the constancy and facility of its service for its own share.  It goes side by side with me in my whole course, and everywhere is assisting me:  it comforts me in old age and solitude; it eases me of a troublesome weight of idleness, and delivers me at all hours from company that I dislike:  it blunts the point of griefs, if they are not extreme, and have not got an entire possession of my soul.  To divert myself from a troublesome fancy, ’tis but to run to my books; they presently fix me to them and drive the other out of my thoughts, and do not mutiny at seeing that I have only recourse to them for want of other more real, natural, and lively commodities; they always receive me with the same kindness.  He may well go a foot, they say, who leads his horse in his hand; and our James, King of Naples and Sicily, who, handsome, young and healthful, caused himself to be carried about on a barrow, extended upon a pitiful mattress in a poor robe of grey cloth, and a cap of the same, yet attended withal by a royal train, litters, led horses of all sorts, gentlemen and officers, did yet herein represent a tender and unsteady authority:  “The sick man has not to complain who has his cure in his sleeve.”  In the experience and practice of this maxim, which is a very true one, consists all the benefit I reap from books.  As a matter of fact, I make no more use of them, as it were, than those who know them not.  I enjoy them as misers do their money, in knowing that I may enjoy them when I please:  my mind is satisfied with this right of possession.  I never travel without books, either in peace or war; and yet sometimes I pass over several days, and sometimes months, without looking on them.  I will read by-and-by, say I to myself, or to-morrow, or when I please; and in the interim, time steals away without any inconvenience.  For it is not to be imagined to what degree I please myself and rest content in this consideration, that I have them by me to divert myself with them when I am so disposed, and to call to mind what a refreshment they are to my life.  ’Tis the best viaticum I have yet found out for this human journey, and I very much pity those men of understanding who are unprovided of it.  I the rather accept of any other sort of diversion, how light soever, because this can never fail me.