334 THE POPULAR SCIENCE MONTHLY. 



concentrated force. Transmuted sunlight is in all its fibres, and who 

 shall estimate the dynamic work which has been expended in its 

 structure ? 



Dr. Draper observes that " the beat of a pendulum occupies a sec- 

 ond of time ; divide that period into a million of equal parts, then divide 

 each of these brief periods into a million of other equal parts, a wave 

 of yellow light daring one of the last small intervals has vibrated 535 

 times. Yet that yellow light has been the chief instrument in building 

 the tree." In the delicate texture of its leaves it has overcome molec- 

 ular force ; it has beaten asunder the elements of an invisible gas, and 

 inaugurated a new arrangement of atoms. The old dragon-tree rep- 

 resents forty centuries of this dynamic work a sublime monument 

 reared without toil by the silent forces of Nature ! 



In the outer air it has awakened every note of sound, from the 

 softest monotone to the rhythmic roar of the tempest ; but in its inner 

 chambers has been a murmur and music of life in the ceaseless move- 

 ment of fluids and marshalling of atoms, as one by one they take their 

 place in the molecular dance, which eludes the dull sense of hearing, 

 and becomes obvious only in results. The veil which hides these ulti- 

 mate processes of life has not yet been lifted, and Science pauses in 

 waiting before it, but only waits. 



EAKLT HINDOO MATHEMATICS. 



By Peof. EDWARD S. HOLDEN, 



OF THE NATIONAL OBSERVATORY, WASHINGTON. 



THERE is a certain fascination in our scanty knowledge of the 

 elder nations of the earth, which is due quite as much to their 

 chronological position as to the intrinsic interest of their doings and 

 sayings ; and it owes not a little of its keenness to the very scantiness 

 of that knowledge. 



We are continually told that this is a practical century ; that we 

 are utilitarians in the strictest sense ; that there is no romantic faculty 

 left to us ; that we are apt to scorn all knowledge which has not a 

 direct practical bearing on the daily life and interests of us all. How 

 can we believe this when we would so eagerly hear of the autono- 

 my of the Aztecs, and while we care so little for modern Chili, for 

 example ? 



We can speak with more interest of Karnac than of Bogota, and 

 a mummy is dearer to us than a Mongolian. We require our thoughts 

 to be suggested sometimes by an age of old and quaint habits, of 

 strange people with stranger gods. In our busy life, it is a relief to 

 turn to the Hindoo, who could spare the time " to sit beneath the tree 



