TIME SIGNALS

Otago Daily Times, Issue 17503, 20 December 1918, Page 5

TIME SIGNALS

SENT OUT BY RADIO. NKW ZEALAND STANDARD TIME.

On November 2 it ..was 50 vears since New Zealand's standard time—exactly llj hours in advance of Greenwich time—was adopted as tho mean time for the colony_ The report of tho WeJEngton Philosophical Society on New Zealand standard time, published! in the New Zealand Journal of Science and Technology, give 3 reasons for urging the adoption of a standard time exactly 12 hours in advance of Greenwich mean time. It may bo mentioned that all tho mean-timo clocks at tho Observatory aro already kept exactly 12 hours in of tho Greemijich mean time, and that timo signals are' given in accordance therewith.

rho dairy timo signal is sent from the Wellington Observatory standard clock to some 2400 telegraphic stations by the Telegraph Department every day (except Sundays) at 9 a.m. The operation is an interesting one. A clock in tho telegraph operating; room at Wellington is kept to correct time by comparison with the time signal from the Observatory standard clock. >- A few minutes before 9 a.m. all the telegraph offices are called to attention by tho Morse signal " LS," which is repeated until '. the supervistors call "Time." By this means all tho railway and telegraph offices - receive correct time signals. Tho more accurate , signals required for rating chronometers, are sent entirely auto-. - matically from tho Observatory clock over ' tho telegraph lines. Further experiments have been made* in '' sending out time signals from the Observatory by radio-telegraphy. A series of five signals during tho first five minntea of tho hour is sent from fho Awanni radio station. The Telegraph Department has provided a direct connection between the Observatory clock and a relay at Awanui over a. land' lino about 600 miles long. - The relay operates a sounder which serves . as a key to work , tho high-power transmitting apparatus. : The receiving apparatus ' at tho Observatory is capable of receiving the radio timo signals sent out by Awanui, and they have been checked frequently. ; It is possible to hear tho click of the Ob- ■ servatory signal clock with one and\ with the radio receiver on the other ear ~ the radio signal from Awanui is clearly heard. It is not possible to detect any difference, between the two sounds, so that for all practical purposes the .signals may be '•■ considered to be simultaneous. No doubt' there is some slight difference between the ■ two sounds, and steps will be taken to measure the lag by means of the chronograph as soon as some reliable method of, automatically recording tie radio time. •- signals is devised. ,'.V

The radio time signals sent from the Ob-vT ssrvatory, have been received at Tahiti, •'. Karotonga, and other Pacific islands, -while .-. captains of steamers report that the time signals have- been heard at Honolulu.- As radio stations are now constructed afc- : ' Chatham Islands, Rarotonga, Samoa, and other Pacific islands it will be possible to ■ determine the difference of longitude be- • tween those places and the Observatory. In this way the charts can. bo corrected; ■ Similarly, the differences of longitude between the Observatory and the other islands near New Zealand can be determined as ; ' soon as a vessel fitted with radio tele-'-'-' graphio apparatus is available'for tbia 6ep- ; vice. . ,