INGENIOUS DEVICE

Hokitika Guardian, 31 October 1930, Page 3

INGENIOUS DEVICE

CHECK ON LORRY DRIVERS. DUNEDIN, October 28. "An ingenious checking device by means of which the exact time worked by lorry-drivers and their colleagues can be gauged to the minute has been invented by Mr James M. Stevenson of this city. Although the design of this “telltale” clock is comparatively simple the task of fashioning the original idea into something concrete and practical has been by no means easy, and in rendering the invention infallible. Ml Stevenson lias used up a great deal of his spare time for the last three / years. Tilt fundamental parts of each checking device are an ordinary clock (an alarm dock will do), a delicatelybalanced vibrating pencil, and a narrow roll of paper which winds from one spool on to another under the poised point of the inexorable pencil. The larger spool is made to revolve by the minute axle of the clock and it in turn draws the paper across from the other spool. When the vehicle is in motion the pencil keeps up a rapid and regular tapping on the slowlymoving paper, the least travelling vibration being sufficient to set it going. If necessary the device will act for ten hours a day an dwhen at the end of the day the scroll is removed one can tell by placing it along a ruler marked to scale precisely how long driver so-and-so had 'or lunch, how long it took him to load up at “x,” and how long it took him to travel from here to theie or vice versa. So accurate is the system that even a stop to allow a tram to pass is recorded.