the Contortioiis in PalcBozoic Strata. 59 



twenty-four hours. The respective velocities and diameters 

 of Venus and the Earth nearly correspond. 



Now gTanting, for the sake of argument, what is by no 

 means improbable, that all the planets had the same initial 

 rate of axial velocity, and granting also that currental in- 

 fluences were in each, continually tending to bring about a 

 stoppage, what was likely to happen would be nearly as 

 follows : 



Jupiter and Saturn being large bodies, would, notwith- 

 standing these retarding forces, maintain their respective 

 velocities for a lengthened period, just as a heavy fly-wheel 

 acts as a more efficient reservoir of power, and runs longer, 

 from the same impulse, than a light one. The motion of 

 the earth as a small sphere would be speedily slackened, 

 whilst the satellites (they being of diminutive size, and, 

 moreover, subject to an inordinate amount of attraction from 

 their respective planets) would soon come to a standstill, 

 their axial revolution ceasinor altoof ether. 



Venus and Mars would seem to present an anomaly, since, 

 having no satellites, they could have no lunar tides. The 

 apparent anomaly, however, diminishes as examination 

 proceeds. Venus would have a considerable solar tide, whilst 

 the currents running from her poles to her equator must, 

 from the intense heat to which the planet is subjected, be 

 greatly in excess of thos^H^ng upon the earth. Mars, from 

 its small size, might ai^^ave a considerable solar tide. 

 There is, however, a difficalty with respect to this planet 

 which I am utterly unable to explain away. 



What, however, would go far to show that the axial 

 velocities of the several planets are not constant, is the 

 discrepancies manifest in the respective spheroidities of the 

 bodies as compared mth the rate of then' diurnal revolutions. 

 Taking the spheroidity of Jupiter to be what it ought to be 

 from the tremendous velocity with which that orb revolves, 

 that of Mars would be greatly in excess of the amount 

 assignable to it by calculation. To my mind the cause of 

 this hes in the fact that Jupiter, as a large body, and retain- 

 ing its heat longer, is not yet completely solidified, or has 

 only a proportionately thin crust, and is, therefore, sufficiently 

 plastic to allow of gravitating forces acting at once, and as 

 soon as they in any way preponderate over the centrifugal 

 force, giving the planet spheroidity. Mars, however, being 

 of much smaller dimensions, would soon lose its heat, and 

 as soon grow rigid. From this cause the latter planet might 



