THE TIME BALLS OF MAURITIUS

Abstract

The time ball service at Port Louis, Mauritius started in April 1833, six months before the Greenwich service. It was established by John Augustus Lloyd who had been appointed Surveyor-General and Civil Engineer in 1831. He was a man of energy and initiative who soon developed a well-equipped observatory and a time service. His chosen arrangement, described in a presentation by Sir John Herschel in London during 1836, was unlike the design for Greenwich. It used a stationary black ball on a white background behind a shutter whose complete closure, not the moment of release, signalled the exact time. Lloyd departed Mauritius in 1849, leaving a legacy of engineering and astronomical achievements. There is some evidence that a conventional time ball had been erected on the roof of the old observatory, possibly for experimental purposes. The time service appears to have deteriorated through the 1850s and 1860s, with only an intermittent flag signal for an extended period, although a new time ball had been erected high on Signal Mountain in 1866. It was rejuvenated when the Royal Alfred Observatory became operational in 1874. Lists of time signals from 1880 onwards include a large black ball on Signal Mountain. A smaller white ball with a larger drop height was introduced as the new principal signal near the Port Office in March 1907. Both time balls appeared in some international lists up to 1945, but publications in Mauritius have indicated much earlier withdrawal of the time ball on Signal Mountain.