A Tell-Tale Clock

Waipukurau Press, Volume XXIV, Issue 126, 29 October 1930, Page 8

A Tell-Tale Clock

TO CHECK LOBBY DRIVERS.

A DUNEDIN INVENTION.

An ingenious checking device by means o! which the. exact tinfe worked by lorry-drivers and their colleagues can be guaged to the minute has been invented by Mr James M. Stevenson of Dunedin, states the “Dominion’s correspondent. 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.

The fundamental parts of each checking device arc an ordinary clock (an alarm clock will do), a delicately-

balanced 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 4he scroll is 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.