the level of an ordinary one as soon as it is interrupted and disturbed, its attention distracted and drawn off from the matter in hand; for its superiority depends upon its power of concentration—of bringing all its strength to bear upon one theme, in the same way as a concave mirror collects into one point all the rays of light that strike upon it. Noisy interruption is a hindrance to this concentration. That is why distinguished minds have always shown such an extreme dislike to disturbance in any form, as something that breaks in upon and distracts their thoughts. Above all have they been averse to that violent interruption that comes from noise. Ordinary people are not much put out by anything of the sort. The most sensible and intelligent of all the nations in Europe lays down the rule, Never Interrupt! as the eleventh commandment. Noise is the most impertinent of all forms of interruption. It is not only an interruption, but also a disruption of thought. Of course, where there is nothing to interrupt, noise will not be so particularly painful. Occasionally it happens that some slight but constant noise continues to bother and distract me for a time before I become distinctly conscious of it. All I feel is a steady increase in the labor of thinking—just as though I were trying to walk with a weight on my foot. At last I find out what it is.
Let me now, however, pass from genus to species. The most inexcusable and disgraceful of all noises is the cracking of whips—a truly infernal thing when it is done in the narrow resounding streets of a town. I denounce it as making a peaceful life impossible;
