366 P. E. Chase— Velocity of Primitive Undulation. 
resonator. But this is such a small fraction of the entire heat 
in the flame, that it is far within the actual fluctuations in its 
temperature, and even if the flame were constant in tempera- 
ture, this small increase could not be detected by any known 
thermometric method. We cannot therefore determine the 
Art. XXXIII.— Velocity of Primitive Undulation ; by PLiny 
EARLE CuAse, Professor of Physics in Haverford College.* 
enry’s experiments have shown that there may be ponder- 
able resistance occasioned by imponderable agency ; Plateau’s, 
i ses; Anderssohn’s, that 
so-called attractions may be explained by thrusts as well as by 
ulls; my own, that purely Seotinbinat- ibrati 
forces may be 2 fae developments, has a constant, or a varia- 
ble velocity. The hypothesis of constancy seems to me more 
probable a priori, and the subordinate variability, spiel = 
Mi 
varies as the inverse square of the distance, and the inertia 
varies as the mass, Gali 
ton’s laws of motion with reference to centers of force, and the 
* Read before the American Association at Hartford, Aug. 13, 1874. 
+ Proc. Amer. Phil. Soc., xiv, 141-7, a 
