ECLIPSE OF SUN.

Press, Volume LXIII, Issue 18889, 3 January 1927, Page 8

ECLIPSE OF SUN.

WHAT EARLY RISERS MAY SEE TO-MORROW. (BPECIALLT WBITTES TOS THB P8159.) . (By E. G Hogg, M.A.. F.R-A-S ' There will be an annular eclipse^ of the sun to-morrow which will c * s in Christchurch as a partial echps . Tlie first- contact of the moon »» sun will occur-for an Christchurch--at, 0..» a.m.. « est phase will bo seen at M 4 a.m.. ivhen about four-fifths of the suns will I*, obscured, and ihe eclipse ™lt end at 7.'JO a.ni. , The line of anuulanty begms u tho Tas.iL Sc., about 200 tho"Lt a reme passes Russell, crosses the Bay of Plentj , course in the Atlantic Ocean. Hie narrow strip ot' the earth s sui faca along which the complete annu us may te observed is about thirty miles wide in the part which crosses New Zealand. The central stage of the eclipse will be reached at Russell at G.'2o a.m., and for some thirty seconds tho sun will be seen there as an extremely narrow bright ring surrounding the lunar disc, which will be of an almost inky blackness. Though an annular eclipse does not compare in beauty with a total eclipse wnen for an all-too-brief period the corona —the glory _of the sun as the ancients called it —flashes into view, still it is an impressive sight and worth travelling a long way to see. As tho intensity of the sun's light during the concluding stages of tho j eclipse will be considerable, observers should provide themselves with some means of protecting tho oye. If th© time-honoured "smoked glass" is used, care should be taken to see that tho deposit of soot is of uniform thickness and of sufficient density to make the sun-lit landscape appear quite sombre; screens of coloured glass—preferably green —may be used, but best of all is ft badly-fogged photographic plat 4 if free from patchiness. The only scientific importance which attaches to an annular eclipse arises from the fact that it affords an opportunity for determining with great precision the relative positions of the sun and moon at a given instant. A small discrepancy exists between the observed place of the moon in tho heavens and that predicted by theory for which no satisfactory explanation has as yet been found, though there is a growing opinion that it arises from some minute fluctuations in the rate at which the earth is rotating on its axis or, in other words, that the earth is not. the perfect timekeeper it was supposed to be. It is therefore desirable that the exact position of the moon relative to the sun should be measured on every possible occasion so that we may learn as fully as we can the amount by which theory and observation differ. An annular eclipse affords such an opportunity, as a photograph of the eclipsed sun taken at a known instant of time can, when carefully measured, give the required information with a high degree of accuracy. A scientific party under the, charge of tho Government Astronomer, Dr. Adams', is visiting Russell for the purpose of taking the requisite photographs, and it is to be hoped that suitable weather conditions will prevail during the time of the eclinse. •

In this connexion it is perhaps permissible to draw attention to a curious notice framed and hung up in the vestry of a church at Ramsgate:— Notice.

In consequence of the eclipse of tho sun occurring during tho hours of Divine Worship on Sunday next,_ May ,15th, St. George's Church will be closed on the afternoon of that day.

(Signed) JOSEPH LOW, Churchwarden

May 14th, 1836.' A reference to the Nautical Almanac for that year tells us that the eclipse was annular, though not central at Ramsgate.