# Page:Popular Science Monthly Volume 6.djvu/66

56

THE POPULAR SCIENCE MONTHLY.

the commencement of the ascending part of one step-curve belonging to the right foot we will let fall upon the staff a perpendicular (a); this line will determine the commencement of the pressure of the right foot. A perpendicular (b) let fall from the end of the curve will determine where the pressure of this foot ends. Between these two points let us trace a broad white line; it will express, by its length, the duration of the pressure of the right foot. A similar construction

Fig. 10.

made on line 1, from the succeeding step-curve, will give the notation of the pressure of the left foot. The notations of the left foot have been shaded with oblique lines, to avoid confusion.

Between the pressure of the two feet there is found to be silence in the rhythm; that is to say, the expression of that instant of the course when the body is suspended above the ground.

If we note in this manner the rhythms of all the paces used by man, we shall obtain a synoptical table which will much facilitate the comparison of these varied rhythms. Fig. 11 represents the synoptical,

Fig. 11.—Synoptical Notation op the Four Kinds op Progression used by Man.

of the four kinds of progression, or paces, which are regularly rhythmical, and in which the two feet act alternately. Line 1 represents the notation of the rhythm of the walking-pace. The pressure of the right foot upon the ground is represented by a thick white stroke, a sort of rectangle, the length of which corresponds with the