THE FUNCTION OF LARGE TELESCOPES. 



By George E. Hale. 



The annual exhibitions of the New York Academy of Sciences aftbrd 

 excellent opportunities for studying the progress of science. The pho- 

 tographs and specimens gathered here tonight are substantial evi- 

 dence that in no department of research have investigators been idle 

 during the last twelvemonth. So true is this, that to sketch the year's 

 advances in even a single field would consume more time than is 

 allotted to the annual lecture. It therefore seemed to me wise, in 

 responding to the courteous invitation with which I was honored by 

 the council, to select a subject involving certain details of astronomical 

 progress, without attempting to undertake the inviting task of portray- 

 ing the rapid advances which make up the recent history of the science. 

 I accordingly invite your attention to some considerations regarding 

 the function of great telescopes. 



On the 21st of last October, in the presence of a large company of 

 guests, the Yerkes Observatory was dedicated to scientific investiga- 

 tion. The exercises were held under the great dome of the observa- 

 tory, beneath the 40-inch telescope. Is there reason to suppose that 

 some in the audience, particularly those having no great familiarity 

 with astronomical instruments, were inclined, in the course of the reflec- 

 tions to which the occasion may have given rise, to attribute to the 

 great mass of steel and optical glass rising far above their heads some 

 extraordinary and perhaps almost supernatural power of penetrating 

 the mysteries of the universe ? It is not at all unlikely that this was 

 the case. For there apparently exists in the public mind a tendency 

 to regard astronomical research with a feeling of awe which is not 

 accorded to other branches of science. In its power of searching out 

 mysterious phenomena in the infinite regions of space, a great telescope 

 seems to stand alone among the appliances of the investigator. Partly 

 because of this special veneration for its principal instrument, and per- 

 haps still more on account of the boundless opportunity for speculation 

 regarding the origin and nature of the universe, astronomy appears to 

 command the interest of a great portion of the human race. No doubt 

 there are also historical reasons for the special attraction which the 



1 An address given at the fifth annual reception of the New York Academy of 

 Sciences. Printed in Science, Vol. VIT, No. 176, May 13, 1898. 



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