INGENIOUS DEVICE.

Waikato Times, Volume 108, Issue 18166, 3 November 1930, Page 3

INGENIOUS DEVICE.

CHECK ON LORRY DRIVERS. "TELL-TALE” CLOCK. • 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 Dunedin. 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 Mr Stevenson has used up a great deal" of his spare time for the last three years. That,-fundamental parts of each checking device are an ordinary clock (an alarm clock will do), a delicately-ftilanced 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 slowly-moving paper, the least travelling vibration being sufficient to set it going. -- If necessary the device will act for ten hours a day, and when at the end of the day the scroll in removed one can tell by placing it along a ruler marked to scale precisely how long driver so-and-so had for lunch, how long it took him to load up at “x," and how long it took him to travel from here to there, or vice versa. So accurate is the system that even a stop to allow a tram to pass is recorded.