i9o6] MICHELSON— FORM ANALYSIS. 115 



the properties of the Hquid) determines the " period " of the rhythm. 

 The drops or loops once formed produce vortex motions in the 

 adjacent Hquid which tend to separate them, and the action of these 

 quasi repulsions is the stronger the closer the drops are to each 

 other. These will consequently separate until the '' repulsions " are 

 equal — that is, till they are equidistant. 



The same general explanation holds if the original drop is 

 transformed into a ring. 



The result is a beautifully regular (but inverted) dichotomous 

 (tri- or tetrachotomous) branching, closely resembling vegetation. 



The study of symmetry is doubtless of relatively subordinate 

 importance from the point of view of the specialist — though Haeckel 

 rightly insists on its significance in the evolution of the lower 

 organisms. 



In the study of crystallography considerations of symmetry are 

 of high value ; and a clear conception of relations of symmetry often 

 wonderfully simplify the most abstruse problems in mathematical 

 physics. 



In the construction of buildings and bridges and engineering 

 works in general as well as in machinery and scientific apparatus, 

 and even of common tools and utensils, — the very necessities of the 

 case have enforced a more or less complete symmetry of parts and 

 of the whole. 



Indeed, it is a common experience that the design of a piece of 

 machinery may be so altered as to make it symmetrical often with 

 a surprising increase in efficiency as well as beauty. 



In designing for the sake of decoration, symmetrical forms are 

 everywhere manifest, and the perception of their mutual relations 

 is indispensable to the student of art. Occasionally, however, there 

 is in decoration a deliberate departure from symmetry, and such a 

 variation may greatly enhance the beauty and effectiveness of the 

 design. We tire of too great uniformity even of agreeable kinds, 

 and the element of variety is as important in art as an occasional dis- 

 cord is in music — its purpose being to heighten the effect of the 

 succeeding harmony. 



One of the great disadvantages of the modern tendency to ex- 

 treme specialization in research is the loss of companionship of 



