Modern Astronomy: Being Some Account of the Revolution of the Last Quarter of a Century

able accurate actual advantage already astronomical better bodies brightness called carried cause century changes circle compared complete considerable course described determine difficult direction discovery distance double doubt drawing Earth eclipse effect examination existence fact fixed follow give given Greenwich hand Hence hope idea illustration images important instance instrument interest kind knowledge known largest lens light limitation lines look Mars matter means measure ment method mirror months Moon motion move nearly nebula object observations Observatory obtained orbit ordinary pair pass perhaps period photographic Pickering picture planet plate position possible practically present Professor reason recently reference regarded remain remarked rotation round Royal satellites scale seen separate shown spectroscope spectrum stars success Sun's taken telescope tion transit-circle turn University whole