Other formats

    TEI XML file   ePub eBook file  

Connect

    mail icontwitter iconBlogspot iconrss icon

The New Zealand Railways Magazine, Volume 5, Issue 2 (June 2, 1930)

The Cyclegraph

The Cyclegraph.

To overcome these drawbacks use was made of the “cyclegraph.” This apparatus consists of a small electric light attached to the hands, or any other member involved in the process. A photographic plate or film is exposed throughout the time the motion is being studied, with the result that a path of light resembling a white wire is seen upon the plate. This white line represents the motions used during the observed process. Later it was used with a stereoscopic camera to show the path in three dimensions. This record, however, lacks the time element. It is quite impossible to know from this record the time occupied in the motion. There came the difficulty of correlating time and motion, which earlier investigations had combined. This defect was then overcome by using a tuning fork, which, vibrating at a known speed, was connected with a “make and break” contact. This device gave the motion in dashes, and as each dash represented a definite space of time, any portion, or even the complete motion could be determined in a time name. (See illustration No. 2 B.) It further indicated the relative speed of different parts of the motion. It will at once appear that dashes in close proximity indicate quicker movement than those with a greater distance between.