10 On the Cosmogony of Moses. 
which render it probable,” I found only a well-reasoned refuta- 
tion of the conjecture that, in the Mosaic history of the creation, 
the word day means an indefinite portior of time. Towards 
the close of the argument, the bishop says, “ By what descrip- 
tion could the word day be more expressly limited to its literal 
and common meaning, as denoting that portion of time which 
is measured and consumed by the earth’s revolution on her 
axis? That this revolution was performed in the same space of 
time in the beginning of the world as now, | would not over 
confidently affirm.” This last is the only sentence in the ser- 
mon, that connects Bishop Horsley’s name with the supposition 
of a slower revolution; which I shall now consider a little on 
the ground of its intrinsic value. The rotation of the planets 
on their axis seems exempt from the accelerations and retarda- 
tions to which all their other motions are subject. No inequa- 
lity has ever been detected in the rotary motion of the earth; and 
the relation betweenits polar and equatorial diameters shows, 
that when it assumed its present figure the centrifugal force of 
its particles, and consequently the rapidity of its diurnal revolu- 
tion, could not be much different from what they are at present. 
But it may be said, that when the rotary impulse was given, thé 
matter of the earth constituted the Shell or crust of a hollow 
sphere ; that afterwards this crust, being broken, fell in towards 
its centre, and formed a spheroid of diminished magnitude ; 
and that, in consequence, the rotary motion of the spheroid must 
(in a certain proportion to its diminution) be more rapid than 
the original diurnal revolution of the hollow sphere. That an 
acceleration of the earth’s rotation must have resulted from such 
a catastrophe is mathematically demonstrable ; but besides that 
the supposition is wholly gratuitous, it would give no effectual 
support to the hypothesis, unless a magnitude were given to 
the original hollow sphere, which the most visionary imagination 
would scarcely dare to assign. Admitting, however, for a mo- 
ment this hypothesis of a slower revolution, 1 would ask, Of what 
duration was the earth’s primitive diurnal rotation ? Was it one 
thousand, or one hundred, of our years? Although the greatest 
of these periods would, perhaps, be too short for the purpose 
assigned it, let us take only half of the least, and inquire what 
would be the state of the vegetable and animal world deprived 
of light and heat during five-and-twenty years? for such, it 
would appear, must have been their condition, at least after the 
fourth day, on the supposition of the diurnal revolution of the 
earth being equal to no more than fifty of our years. 
There remains to be noticed the conjecture often made, that 
in the Mosaic cosmogony the word day signifies an indefinite 
portion of time, This conjecture seems completely disproved 
by 
