September 18, 1914] 



SCIENCE 



401 



dence of it in the moon's motion. Eeasons 

 may exist for this : but until the mechanism 

 of the action can be made more definite it is 

 hardly worth while to belabor the point. 



The hypothesis presents many difficulties- 

 Even if one is disposed to admit provision- 

 ally a correlation between the four curves 

 — and this is open to considerable doubt — 

 it is difficult to understand how, under the 

 electron theory of magnetic storms, the mo- 

 tions of moon and planets can be sensibly 

 affected. I am perhaps catching at straws 

 in attempting to relate two such different 

 phenomena with one another, but when we 

 are in the presence of anomalies which 

 show points of resemblance and which lack 

 the property of analysis into strict periodic 

 sequences some latitude may be permissible. 



In conclusion, what, it may well be asked, 

 is the future of the lunar theory now that 

 the gravitational effects appear to have 

 been considered in such detail that further 

 numerical work in the theory is not likely 

 t« advance our knowledge very materially ? 

 What good purpose is to be served by con- 

 tinuous observation of the moon and com- 

 parison with the theory 1 I believe that the 

 answer lies mainly in the investigation of 

 the fluctuations already mentioned. I have 

 not referred to other periodic terms which 

 have been found because the observational 

 evidence for their real existence rests on 

 foundations much less secure. These need 

 to be examined more carefully, and this ex- 

 amination must, I think, depend mainly on 

 future observations rather than on the rec- 

 ords of the past. Only by the greatest care 

 in making the observations and in elimi- 

 nating systematic and other errors from 

 them can these matters be fully eluci- 

 dated. If this can be achieved and if the 

 new theory and tables serve, as they should, 

 to eliminate all the known effects of gravita- 

 tion, we shall be in a position to investigate 

 with some confidence the other forces which 



seem to be at work in the solar system and 

 at which we can now only guess. Assist- 

 ance should be afforded by observations of 

 the sun and planets, but the moon is near- 

 est to us and is, chiefly on that account, the 

 best instrument for their detection. Doubt- 

 less other investigations will arise in the fu- 

 ture. But the solution of the known prob- 

 lems is still to be sought, and the laying of 

 the coping stone on the edifice reared 

 through the last two centuries can not be a 

 simple matter. Even our abler successors 

 will hardly exclaim, with Hotspur, 



By heaven, methinks, it were an easy leap 



To pluek bright honor from the pale-faeed moon. 



They, like us and our predecessors, must go 

 through long and careful investigations to 

 find out the new truths before they have 

 solved our difficulties, and in their turn 

 they will discover new problems to solve 

 for those who follow them: 



"For the forttme of us, that are the moon's men,, 

 doth ebb and flow like the sea, being governed, as 

 the sea is, by the moon." 



B. W. Beown 



BOTANY IN THE AGSICULTUBAL COLLEGE 

 Five years ago, there was, I believe, no col- 

 lege in the United States which required that 

 plant physiology be studied by any student of 

 agriculture. There were a very few col- 

 leges in which it was possible for students 

 of agriculture to take as much as one year's 

 work in this subject, but the number of such 

 places was exceedingly limited and remains, 

 so. The college of agriculture of the Univer- 

 sity of the Philippines was founded at that 

 time; and having a free hand in planning its 

 course of study, I provided that every student 

 not only could but must take one full year of 

 plant physiology, and that students taking the 

 course regularly must have this year of physic 

 ology before being admitted to the study of 

 agriculture itself. 



There were several reasons for taking this, 

 rather radical step. Decidedly the strongest 



