Sometimes the substitution of a mechanical appliance for brain-work is what we want. What, for instance, is the use of tiring one’s brain and impairing its usefulness for other needed work by forcing it to perform such a mechanical operation as adding a column of figures? Every library that can afford to own an adding machine ought to have one. The ones that can not afford it usually do not need it. While we are discussing the mal-employment that does its harm by tiring out the worker, physically or mentally, and making him unfit for other work, we must not neglect to say a word about unnecessary talk. Nothing is so tiring to the brain as talk. I sometimes think that if we were all forced to do our work in silence we would get along more rapidly even if we had to communicate with each other in writing. If a man were in charge of a piece of complicated machinery, and if he feared that something had got into it to clog it, while his knowledge of its elementary parts was still so slight that he could not tell which particular bit in all the moving mass was helping it on and which was hindering it, what would he do? He could remove the pieces, one by one, and watch the effect. If the machine refused to run without a certain piece, he would conclude that it was an absolutely necessary part; if it still ran, though with difficulty, he would conclude that the part, though not necessary, still promoted efficient operation; if removal resulted in no change at all, the piece was evidently either an unnecessary part, or an alien piece not so placed as to interfere with action. If the machine worked decidedly better after removal, the removed element must have been a clog--was, in fact, mal-employed. How many of us feel like submitting to this test? If you should stop your work, would the library machine run along quite as usual? Or would it limp? Or would it refuse to run at all? Or would it--O distasteful thought!--would it jump ahead and function with greater speed and smoothness? I believe in vacations; and yet I rather like to feel that the absence of an assistant on vacation makes a difference. And if every one in her department looks forward with fond expectation to her return and greets her with looks of satisfaction and sighs of relief, I cannot help feeling that she is a more integral part of the library machinery than if her return were generally regarded with indifference or were dreaded as a sort of calamity. When every one feels that she can work much better when Miss Blank is away, I am forced to inquire whether in truth Miss Blank is not a clog in the wheels instead of a cog, and whether a permanent vacation would not be the proper thing for her.