an exertion, I lost much of my sleep; a privation that, under the circumstances explained, deterred me from trying the experiment too often. For one or two years, I accomplished more than I have here claimed, viz., from six to seven thousand miles in the twelve months. Let me add to this slight abstract of my own experience, in a point where it is really difficult to offer any useful advice, (the tastes and habits of men varying so much in this chapter of exercise,) that one caution seems applicable to the case of all persons suffering from nervous irritability, viz., that a secluded space should be measured off accurately, in some private grounds not liable to the interruption or notice of chance intruders; for these annoyances are unendurable to the restless invalid; to be questioned upon trivial things is death to him; and the perpetual anticipation of such annoyances is little less distressing. Some plan must also be adopted for registering the number of rounds performed. I once walked for eighteen months in a circuit so confined that forty revolutions were needed to complete a mile. These I counted, at one time, by a rosary of beads; every tenth round being marked by drawing a blue bead, the other nine by drawing white beads. But this plan, I found in practice, more troublesome and inaccurate than that of using ten detached counters, stones, or anything else that was large enough and solid. These were applied to the separate bars of a garden chair; the first bar indicating of itself the first decade, the second bar the second decade, and so on. In fact, I used the chair in some measure as a Roman abacus, but on a still simpler plan; and as the chair offered sixteen bars, it followed, that on covering the last bar of the series with the ten markers, I perceived without any trouble of calculation the accomplishment of my fourth mile.