P. E, Chase on Mechanical Polarity. 93 
other hand, in water-spouts and tornadoes, the flashes seem to 
follow, instead of preceding, the equalizing action of aérial 
gravitation. We have never yet been able to measure the 
electrical and gravitating momenta in such instances of violent 
commotion; but we can hardly doubt their exact equivalence, 
in view of the well-established law, that “action and reaction 
are always equal and in opposite directions.” And in conside- 
ration of such probable equivalence, it does not seem unreason- 
able to quote them as standing evidences of that long-desiderated 
link in the chain of kinetic unity, for the recognition of which 
the way has been partially prepared by Henry’s discovery of 
the tendency to equality of electric momenta, and the cor- 
relation of intensity and quantity-currents (this Journal, [1], 
tween the thermal and magnetic curves (Hobarton Obs, I, xli; 
Toronto Obs., I, xxxviii; St. Helena Obs., I, 38, &c. &c.) have 
m 
129), barometric tides (Ibid., 
d P: 
120, sy 
Pp. 123-7), winds (Ibid., p. 121, and Proc. A. P. S, x, 104), 
thermal char fase: Sabina. Yoo Bb) and lunar attraction 
Prog, A, P.S.,, ix, 484-8; rans. A. P. S., xiii, 129; and Gen, : 
