| Show great telescopes it la Is frankly to bo be admitted that for ordinary work enormous inspru moats tire not those of moderate dimensions will do for far more easily and rapidly tho work of which they are calab capable a it would wool ho be poor economy to shoot abbot squirrels with fifteen inch cannon observe ers with fraller justou in onto it if they have sharp eydi and uso thena them faithfully can always flod enough to do I 1 0 and can do it well but bat the great erent telescope telee cope has two advantages which are decisive in the first place it collects more liht light and so on makes it po possible ibis to use higher ir powers powen I 1 and thai virtually to draw nearer than can he be W with ith a smaller one on and lid in thu tho nex next place in consequence or of what iq 4 known as diffraction the image firing of ota a luminous point made by a largo lens ions li 14 l i smaller ani and sharper than that hat made hy by fl i small squall CHIP gnp tito smaller aid tier it ahn tolese ope the larger lamer tire are 11 the 10 so 80 called disks or of tile the stairs so that in the ilia chao list of it close double star starter for Ills hince where our nine inch aple hows only tin an oval disk the three inch shows two title tine distl distinctly lie OY separated points it Is bluit the phere disturbance tur bance which prevail to t H greater or les lesi lem i extent very serious ly IY street affect tho with large in ili c tho power of the prince of tho ilar which Is to BH ail a crono mer iner tile lie very type of the total 10 depravity of nr things on nine cleair night i out nut of ten deprives it i great telescope of much of its ju qt tin superiority perlo rity so that in an ordinary night a good observer with an a 11 forture 11 of a f twelve twe iva or fifteen inches ami inako out aill that flint call tie ile feltey seen been with ith twenty four or thirty inches inched ut tile the same time and yet the ilia writer has continually verl r iv tied 11 nl lu in his experience the observation of mr clark who bald you can call always ways bee be with it largo telescope everything shown hy by a smaller srun ller one it a little better batter it if thu tho seeing abelo IS id bad Immen gly betler if it Is rood good but when A really good night cornea comes as an once IQ in it while it 16 does then to a great telescope heaven opens 13 new ew appear now new forms forma and fra fee lures are old illusions illusion are dissipated und vatic and to babore beyond beyond t chiq b q gremli possible easy still and accurate in ill fact tile tha of wanting bautin wa utin still larger telescopes la Is identically the ilia sams as that of wanting a telescope telo iacopa at all of course it la Is I 1 w possible jo predict what discoveries will be made with the great lick licit telescope tele when it is erected on its mountain of privilege very likely anne it la Is not now nov to go out outfit at night to think find and pick up discoveries as one would rather gather lowers flowers in ili ol a forest but we way may be sure auro of this that it will collect data with I 1 micro I 1 meter meer I 1 camera and spectroscope w which aich will remove many old dim bullies cul lies will clear up doubts will wll actually advance our I 1 and what Is id still more important will prepare the way and hew the steps for still higher climbing toward tho the a tars stars Prof professor emor young in thaI the forum brum lop for september |
