POWERFUL TELESCOPES

Evening Post, Volume CII, Issue 41, 17 August 1921, Page 15

POWERFUL TELESCOPES

, With tlie completion of tlie great 72in reflecting.telescope for'the Dorhinion Astronomical Observatory at Victoria, Canada, and ajso of ■ th.e\ lOOm mirror for the 'Carnegie Solar Observatory at Mount Wilson, California, both of)which ..will probably be in use, by/the time these lines ap)>ea!', a new era (says the Theosophical PathJ. will begin in research into tho uttermost depths of spate. Those two instruments are the largest and most powerful telescopes ever made, and they represent extraordinary triumphs over optical and engineering- difficulties. The mirror at Mount Wilson, Bft 4in "in din-meter, is 13in thick and woighs H tons. The problem of transporting this enormous mass of glass to the summit of ■ the mountain, 06S6l't above soa-lovel| without accident, was a -most difficult one; speiSial roads had to bo built, and unexpected obstacles .surmounted. Efforts were made by ill-xlisposed persons to or destroy the priceless mirror, but it is now safely housed in its final resting-place. It took. five years for the cjpetfc glass. makers afc the St, Gobain factory, Paris, to cast a perfect mirror. Fortunately for science it wa-s a'eady to be sent to America- a tew weeks before the outbreak of the war.

It is doubtful whether these enormous telescopes will bo greatly used for the Btudy of tho planets; up to the present rather smaller ones have proved more suitable for that' purpose. It may bo ftha't some now and startling planetary discoveries will bo made by means of the lOOm, and they would certainly be welcome, for it is absolutely true that astronomy knows very little indeed about the physical cpndition of tho planets.