TOWN CLOCK

Timaru Herald, Volume CXXXIX, Issue 20108, 15 May 1935, Page 8

TOWN CLOCK

THE NEW WINDING SYSTEM

ELECTRICITY’S PART Few of the many Timaruvians who have come to regard Timaru's town clock—which since 1912 has ticked away the hours accompanied by its familiar chimes —as a public necessity, realise the extent of the mechanism behind its daily duty, or appreciate the fact that its maximum of error is now less than one second a week. Few realise also that it Is the only turret clock in New Zealand automatically wound on the Huyghen principle. This improvement, which was brought about when the clock was housed in its new tower above the Municipal Chambers, was explained to a representative of “The Timaru Herald” yesterday by Mr A. E. Watkins, borough electrical engineer.

When the clock was removed from the Post Office tower it was decided to wind it electrically to save the weights dropping a distance of 80ft. and thus encroach on valuable space in the Council buildings. The new winding system has been successfully brought into being by the use of Huyghen’s endless chain harnessed to an electric motor. Huyghen’s system, which was invented in 1700, can readily be adapted to modern methods, and has proved a great success so far as the Timaru clock is concerned. The weights now drop a maximum of 12ft. for a 24 hour run. The electric motors wind the clock when the weights have drooped only 4ft. In other words, the clock is automatically wound six times a day. The new system has now been in operation for three months without a hitch. The biggest problem was to arrange the winding gear so that if the electricity was cut off the clock would not stop. The problem was successfully surmounted, however, and the current can be cut off for 12 hours before there will be any stoppage of the clock. Under the modern conditions of electrical supply in New Zealand, it can be realised that any stoppage of the clock will practically be an impossibility. The clock which was built in Wellington in 1912, is an exact replica—on a smaller scale—of the clock in Westminster tower that houses the famous "Big Ben” bell. In its old home the clock was erected on wooden foundations in a very unstable tower which often rocked with the wind and affected the timekeeping. It is now erected on concrete foundations which are an integral part of the tower, and it has been found from experience that any movement—if any—of the tower has no effect on the clock’s timekeeping. The clock is checked daily at 10.30 a.m., in summer and 11 a.m., in winter with the wireless signals from the Dominion Observatory, and so accurate is this 23 year-old timepiece that its error is less than one second a week. The bell chamber houses five bells and is thoroughly sound proof. Strange to say it has been found that the chimes are noticed less now in the Municipal offices than they were when located over the road in the Post Office. The First Clocks It is interesting to compare the latest improvement to Timaru’s clock with the timepiece of ancient times. A clock is said to have been constructed by Pope Sylvester VII. in A.D. 966, with weights as motive power. Many of the early church clocks were simply striking instruments, with no dial to show the time. In 1288 a clock supplied with bells was put up in Westminster Abbey, and many cathedrals possesed clocks as early as the 14th Century. The famous clock at Strasburg Cathedral was constructed in its original form between 1352 and 1370. Another famous clock of the 14th century was that constructed by Henry de Vick for Charles V. in 1379. The regulating mechanism of these clocks consisted of a verge escapement with a balance. The escapement was applied to a crown wheel, that is, a wheel with serrations cut parallel to its axis. Two pallets engaged with the crown wheel in such a way that*when one was pushed past a tooth, the other was applied to a tooth on the other side. The resistance of the pallets to the motion of the wheel was adjusted by weights fixed on two arms pivoted with the pallets. As the first pallet was pushed clear, the motion was communicated to the arms of the balance which swung round, thus increasing the resistance of the other pallet, which could only be overcome by bringing the balance to rest and reversing its motion. The weights of the balance could be moved along the arm, thus making it possible to regulate the resistance of the escapement and so determine the period of revolution of the crown wheel. The pendulum was adapted to clock mechanism in the 17th century and corrections for temperature were introduced by John Harrison (1693-1776) and Matteo CampaniAlimenis; the latter also invented the illuminated dial plate. Many modifications of the general structure of clocks have been introduced from time to time.