LESSONS OF ECLIPSE.

New Zealand Herald, Volume LIX, Issue 18235, 31 October 1922, Page 5

LESSONS OF ECLIPSE.

THE WALLAL OBSERVATIONS.. ■ . >t DETERMINING THE EESTJLTB j WORK OF SEVERAL MONTHS.- ' j A review of the solar eclipse ohsarv- * 1 atiens carried out at WaEtd,. West Aas- - tralia, by the expedition from the Lick > Observatory,- University of California, waa grvea yesterday by Dr. W. W. ' Campbell, director of tiia obsexvatory, - • who hi a thuoagh passenger by the • Niagara, i | The conditions at Wallal irere expected •} to be good» otherwise the astronomers ■ | would not have travelled so far, Dr. ■ j Campbell sai.d, but ths conditions were •' found to be even better than, waa ex- ■ j pected. Pram the time ci the landing | on August 30 up to three days after the '■eclipse, 26 days in ail, "the sky -as ■ { beautifully', clear by day, and eclipse day, ! September 22, was the most beautiful el 1 ! the whole period. The preparations, ! i therefore, were made under good con- '! ditious, and the expedition from the '! Lick Observatory were ready for the • | critical five minutes in every way, th* '! programme going through in all estentiain 1 ; exactly as planned. The great drawback 1 ; was the dust, -which gave an immense j amount of trouble and finally stopped the i development cf the photographic plates. '! The exposed plates were taken to Broome, ' I where the temperature in the dsrk-rocm ■ I was controlled with ice, and clast was j avoided. . | Observations all Photographic The observations were all photographic, . ■ and the determination of results de- ' | manded expensive and accurate measure' ; | mentß of the plates with powerful , j microscopes, and calculations based upon i the data obtained in this manner. "We ; \ were hoping to be able to complete the j measurements cf some of the photographs,, j secured to test the Einstein theory," said J Dr. Campbell, "but in the four available j days s.t Broome, keeping the mierosccpe [ | busily engaged for 13 hours each day, ' j Dr. Bobert Troanplar and I were able to j j carry through only half the measurej ments demanded by one set ef plates, ; j when it was necessary to pack up for j Perth. The photographic' plates seSKreS I with the four powerful Enstein cameraß | and _ other- instruments , -wtdgh, with j packings, 6901fe., and they ars -en | route te California with the eclipse equipment. Tha study of the platen will be resumed at the lick Observatory' immediately they arrive. Thera are ten pairs of plates secured by the "Sfoftem instruments and it will be seen that the deduction of results will demand work extending through several raonlhs.HJavmrnta is ths Corona, "The solar oorona was photographed with both large and anal! ceiaeras with a view chiefly te studying the motions I within the coronal structure. •It is well known that thiß structure is entirely different at different eclipses, and, therefsn\ motions within the straifture must occur. There is very litiSe evidence m far to i j indicate_ the nature of these motions. The j Australian ; ellipse offered acivantaffes in j this connection. The Link Observavsry . party used a great \aaaera, 40ft. in" foca , i length, and also lent to ilie Adelaide J eclipse. expedition ah exact cupiicate of j the caaKEra. Thesis instrument* recorded thci J i corona on a very large scale, the diameter • i'of the moon's image being about 4|in. j The two. parses, working according' to a ' peearranged' programme, •ecusttd an excel- - lent series of negatives. Copies of the • . Adelaide jfartyV plates wjll be despatehiwi Bto the Lick_ Obserratory. The moon's s shadow ■ neeuired So minutes! in- ~.passing • . from,: 1 the Adelaide-, party's '- staiabtt-' vn the nortfr-eastern cetaer- of 8 South .Australia, and: it 'Is hoped a. ccone pansoa of fhe pfaotogJapha will "gjjfSf «»2ti--6 abla evidence as to the motions "vhich j trans|3ied- in the cwfnal strnctoT^ ''dvaixis d this interval of time J> .-* • Dr. Campbell added that «£ SE •' : Moore was in charge of the five speetron j graphs and all of these instmiueints gave j i him beautiful photographs which,, upon i reaching home, he will etndy in order tos ! hnprove the kuowledge. o£ " the oopana's ■ cHemical ctmsfumiiasi and the physical r conditions trximing vn'thin the corona. j Bilicgiating ihttjm&k of tha Oattsdiaa '• party of astrosiomere. who aiso Bad tbdr headquarters at WsIZsJ, Praltmat <t; A. Chant laid cteaa upon' the amount at (work ret Ux-.be done. It woaHi.' Ee asicJ. be several montla; before the scientific results were drtcrmined.