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SCIENCE 



[N. S. Vol. XXXVI. No. 927 



this prediction came true, and more 

 strangely still, in spite of this prediction, 

 it was proved conclusively that he had 

 nothing to do with the theft. The object 

 glass was carried off and held for ransom 

 by persons who greatly overestimated its 

 value. Langley gave a most interesting 

 account of his experiences with the thieves. 

 He was supported by the trustees of the 

 observatory in maintaining that not a cent 

 should be paid unless the thief could be 

 punished, otherwise no large lens in the 

 country would be safe. Finally he met the 

 thief by appointment, one evening, and as 

 they walked up and down a wooded path, 

 the thief remarked, "You are a gentle- 

 man, and I am a gentleman ; we must trust 

 one another." Finally, the lens was re- 

 turned uninjured, without ransom. 



Langley 's invention of the bolometer 

 opened a line of research which has con- 

 tinued to the present time. He displayed 

 consummate skill and ingenuity in its de- 

 velopment, and extraordinary patience in 

 overcoming the numerous difBculties which 

 presented themselves. Even in those early 

 days he was deeply interested in the prob- 

 lems of artificial flight. We were often 

 together in the woods or mountains and 

 whenever he saw a hawk, or other 

 large bird soaring, he would stop and 

 watch it, saying, "Some day we shall do 

 that. ' ' His discovery of the internal work 

 of the wind was one whose importance does 

 not seem yet to be appreciated. It still 

 seems possible that practical results may be 

 obtained from it. The credit for the in- 

 vention of the aeroplane is due, in a large 

 measure, to him, and he was bitterly hurt 

 at his treatment by the public press after 

 the destruction of his first aeroplane. 

 Later experience shows that another trial 

 might have proved an entire success. 



My acquaintance with his successor, 

 Keeler, was much less intimate, but close 



enough to recognize his charming disposi- 

 tion and rare talents. Astronomy suffered 

 a heavy loss in his early death. In his 

 work here, and on Mount Hamilton, he has 

 left among others two researches with the 

 spectroscope which have become classical. 

 First, the brilliant proof that the rings of 

 Saturn are composed of minute portions 

 revolving independently around the planet. 

 Secondly, a determination of the motion in 

 the line of sight of gaseous nebute. This 

 appears to be the best solution yet found 

 of this problem. It is remarkable that no 

 one has repeated and continued it. Keeler 

 measured only ten of the two hundred 

 nebula now known to be gaseous. 



The work of Wadsworth was more in 

 preparation than in obtaining results, 

 while that of Acting-Director Brashear has 

 been overshadowed by an enthusiasm which 

 has not only rendered this new observatory 

 possible, but will be of the greatest value 

 to it in the future, and inspires us all to 

 renewed efforts by his unflagging zeal. 



The present director. Professor Schles- 

 inger, can give you a better description of 

 his work than I can. But as I fear that 

 he may not do justice to its quality, a brief 

 account of it may not be out of place here. 

 Half a century ago, the character of the 

 work done by astronomers was very different 

 from that undertaken at the present time. 

 It then consisted almost entirely in a study 

 of the positions and motions of the 

 heavenly bodies. In fact, if an astron- 

 omer had a large equatorial telescope, he 

 generally devoted himself to measuring 

 the relative positions of the components of 

 double stars, and if he had a meridian 

 circle, he measured the positions of large 

 numbers of stars, and determined day by 

 day the exact time. At the larger observa- 

 tories the position of the moon and other 

 objects in the solar system were deter- 

 mined. A few far-seeing men of genius 



