The sins of which I purpose to speak are Duplication and Omission. They are peculiar to no one class of persons, to no one business, profession or institution. They are ubiquitous and omnipresent. Those who use the Book of Common Prayer acknowledge them when they confess that they have done those things that they ought not to have done and have left undone those things that they ought to have done. This statement covers other sins, both of commission and omission, than those that I have specified above, but it includes both of them. The peculiarity of Duplication and Omission is that they are complementary so far as the labor and expense involved in them is concerned. Their existence is like that of a surplus and a debt in the same purse. To bewail them is like complaining because you have a thousand dollars that you know not how to invest and at the same time because you owe a thousand that you can not pay. The whole world is out of joint because it is doing twice things that need to be done only once, and at the same time is not doing at all things that ought to be done. The man with the thousand-dollar surplus and the debt of the same amount may obtain quick relief by paying his indebtedness with his balance. The world will be relieved when it takes the energy and the money now expended in wasteful duplication and puts it into the doing of those things that are now left undone because the energy and money necessary to do them are expended wastefully. It is very easy, is it not? As easy as adding plus 10 to minus 10 and getting zero. The surplus and the debt, the duplications and the omissions, extinguish each other and neither of them bothers us any more. Unfortunately there are practical obstacles that do not present themselves in the case of the algebraic sum. These difficulties might occur in the case of the man with the surplus who owed money, if he could be supposed ignorant both of his balance and of his debt, while suffering the inconveniences due to both. This ignorance is the rule, rather than the exception, in the case of ordinary duplications and omissions. Either the duplication is not noticed, because at first sight it does not appear to be a duplication, or when recognized as such, its existence does not seem to be of any consequence. Besides this, both duplications and omissions seem to some to be part of the natural order of things ordained for us and not to be disturbed by the hand of impiety. One hardly knows when to begin with illustrations where there is such a wealth of material, whether we seek it in civics, or history, or science, or business or in domestic economy. As you have doubtless surmised I intend to take the Public Library as my chief field of research, but I must maintain or at least justify my thesis of universality by a preliminary trip through a much broader field.