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SCIENCE 



[N. S. Vol. XLII. No. 1082 



to provide the necessary funds by persuad- 

 ing tliem, and incidentally ourselves, that 

 we do so because important scientific re- 

 sults may be expected from the expedition. 

 This may actually be the case, but we are 

 mainly affected by the same motives as the 

 rest of the community : if the truth be told, 

 we are as curious as they to know what 

 every corner of the earth looks like, and 

 we join them in wishing to encourage an 

 enterprise requiring perseverance and in- 

 volving danger. 



I fully realize that the wish to justify 

 one's own work in the eyes of the world 

 will always lead to fresh attempts to find 

 a formula expressing the objects which we 

 desire to attain. Enough, however, has 

 been said to show that the definition must 

 take account of sentiment, without insist- 

 ing too much upon it. Nor can we hope, in 

 view of the variety of intellectual and emo- 

 tional pleasures which combine to create 

 the charm of science, to include all points 

 of view, but if I were forced to make a 

 choice I should say that the object of sci- 

 ence is to predict the future. The wish to 

 know what lies before us is one of the old- 

 est and most enduring desires of human 

 nature ; often, no doubt, it has degenerated 

 and given rise to perverted and ignoble 

 longings, but its accomplishment, when it 

 can be achieved by legitimate inquiry, is a 

 source of the purest and most satisfying 

 enjoyment that science can give. "We feel 

 that enjoyment each time we repeat an old 

 and perhaps hackneyed experiment. The 

 result is known beforehand, but be it only 

 that we expect the color of a chemical pre- 

 cipitate to be green or yellow, be it only 

 that we expect a spot of light to move to 

 the right or left, there is always a little 

 tremor of excitement at the critical moment 

 and a satisfying feeling of pleasure when 

 our expectation has been realized. That 

 pleasure is, I think, enhanced when the 



experiment is not of our own making but 

 takes place uncontrolled by human power. 

 In one of Heine's little verses he makes 

 light of the tears of a young lady who is 

 moved by the setting sun. "Be of good 

 cheer," the poet consoles her, "this is only 

 the ordinary succession of events: the sun 

 sets in the evening and rises in the morn- 

 ing. ' ' If Heine had been a man of science, 

 he would have known that the lady's tears 

 found a higher justification in the thought 

 of the immutable and inexorable regularity 

 of the sun's rising and setting than in the 

 fugitive color impression of his descent be- 

 low the horizon, and that her emotions 

 ought to be intensified rather than allayed 

 by the thought of his resurrection in the 

 morning — everybody's life contains a few 

 imforgettable moments which at quite un- 

 expected times, will vividly rise in his mind, 

 and there are probably some in this hall 

 who have experienced such moments at the 

 beginning of a total eclipse of the sun. 

 They have probably traveled far, and gone 

 through months of preparation, for an 

 event which only lasts a few minutes. The 

 time of first contact is approaching, in a 

 few seconds the moon is about to make its 

 first incision in the solar disc, and now the 

 observer's thoughts come crowding to- 

 gether. "What if there were a mistake in 

 our calculations? "What if we had chosen 

 a spot a few miles too far north or too far 

 south? "What if the laws of gravitation 

 were ever so little at fault ? — But now at the 

 predicted time, at the calculated spot on 

 the sun's edge, the dark moon becomes 

 visible, and the feeling of relief experi- 

 enced concentrates into one tense instant 

 all the gratitude we owe those who have 

 given precision to the predictions of celes- 

 tial movements, leaving them expressible by 

 a simple law which can be written down in 

 two lines. It is this simplicity of the law 

 of gravitation, and its accuracy which 



