286), "this time is about that in which in rapid walking, according to the Webers, our legs perform their swing.It seems thus not unlikely that both psychical constants, that of the average speed of reproduction and that of the surest estimation of time, have formed themselves under the influence of those most habitual movements of the body which we also use when we try to subdivide rhythmically longer tracts of time."

Finally, Prof.Mach makes a suggestion more specific still.After saying very rightly that we have a real sensation of time -- how otherwise should we identify two entirely different airs as being played in the same 'time'? how distinguish in memory the first stroke of the clock from the second, unless to each there clove its special time-sensation, which revived with it? -- he says "it is probable that this feeling is connected with that organic consumption which is necessarily linked with the production of consciousness, and that the time which we feel is probably due to the work of attention.When attention is strained, time seems long; during easy occupation, short, etc....

The fatigue of the organ of consciousness, as long as we wake, continually increases, and the work of attention augments as continually.Those impressions which are conjoined with a greater amount of work of attention appear to us as the later." The apparent relative displacement of certain simultaneous events and certain anachronisms of dreams are held by Mach to be easily explicable as effects of a splitting of the attention between two objects, one of which consumes most of it (Beiträge zur Analyse der Empfindungen, p.103 foll.).Mach's theory seems worthy of being better worked out.It is hard to say now whether he, Ward, and Wundt mean at bottom the same thing or not.The theory advanced in my own text, it will be remarked, does not pretend to be an explanation , but only an elementary statement of the 'law' which makes us aware of time.The Herbartian mythology purports to explain.

It would be rash to say definitely just how many seconds long this specious present must needs be, for processes fade 'asymptotically,'

and the distinctly intuited present merges into a penumbra of mere dim recency before it turns into the past which is simply reproduced and conceived.Many a thing which we do not distinctly date by intercalating it in a place between two other things will, nevertheless, come to us with this feeling of belonging to a near past.This sense of recency is a feeling sui generis , and may affect things that happened hours ago.It would seem to show that their brain-processes are still in a state modified by the foregoing excitement, still in a 'fading' phase, in a spite of the long interval.

Physiol.Psych., II.263.

I leave my text as it was printed before Münsterberg's essay appeared (see above page 620, note).He denies that we measure any but minimal durations by the amount of fading in the ideational processes, and talks almost exclusively of our feelings of muscular tension in his account, whereas I have made no mention of such things in mine.I cannot, however, see that there is any conflict between what he and I suggest.

I am mainly concerned with the consciousness of duration regarded as a specific sort of object, he is concerned with this object's measurement exclusively.Feelings of tension might be the means of the measurement, whilst overlapping processes of any and every kind gave the object to be measured.The accommodative and respiratory movements from which the feelings of tension come form regularly recurring sensations divided by their 'phases'

into intervals as definite as those by which a yardstick is divided by the marks upon its length.