A frame, A A, is provided with means to attach it to the pedal of any machine. A table, B, supported by springs, E, E, has a vertical movement through the frame A A, and carries a marker, C. The frame carries a drum, D, containing within it mechanism which causes it to revolve regularly upon its axis. The cylindrical surface of this drum, D, is wrapped with a slip of registering paper removable at will. When we wish to take the total foot-pressure, the cyclograph is placed upon the pedal and the foot upon the table. The drum having been wound and supplied with the registering slip, and the marker C with a pencil bearing against the slip, we are ready to throw the trigger and start the drum, by means of a string attached to the trigger, which is held by the rider so that he can start the apparatus at just such time as he desires a record of the pressure.
The following are a few sample sections cut from registering slips illustrating some of the points discovered in these experiments. Only a few strokes of the crank or lever can be shown; it is evident that great space and expense of reproduction would be required to give the entire record for even a small part of a mile. It will be understood, I think, without further explanation, that these curves show the extent and variation of pressure of the foot upon the pedal in order to drive the respective machines under circumstances named and described by the figures and thereafter.
52-inch Ordinary; race-track; getting up steam.
52-inch Ordinary; race-track; speed, eighteen miles per hour.
52-inch Ordinary; race-track; speed, ten miles per hour.
52-inch Ordinary; race-track; speed, ten miles per hour.