CHAPTER II. 
Contents. — Theory of Central heat, causing upheavals, combatted— Kesults 
of a loss of equilibrium by the ICarth, as to change of position of sites 
of defined latitude and longitude— Theories of the Precession of the 
Equinoxes, and of the Tides, nud a new interpretation of these 
phenomena— Recession ot the sea from coasts, not a silting up of 
their harbours— Hypothesis as to age of the Pyramids, and intention 
of the coffer in the King's Chamber — New views as to age of the 
" cave-men " — Hypothesis as to drifts and deposits therefrom — 
Questions inrportaat to the mercantile marine and navy. 
The theory of igneous upheavals of portions of the earth's 
crust, of continental area, is still maintained by some geolo- 
gists, and palaeontologists, to account for the apparent 
elevation of lands above sea surfaces. This theory is based 
upon the mere assumption that the primary state of the 
globe was that of a mass of molten and incandescent matter, 
and that this seething mass, though cooled and hardened 
into a crust externally, still exists beneath this crust, not 
only ready for volcanic action, but actually and simul- 
taneously upheaving and depressing continuously segments 
of the earth's crust at the present day, so that lands are 
raised and depressed, as to the level of the seas upon their 
coasts, while the sea ever retains a " fixed hydrostatic surface 
level." There is, however, absolutely no proof of this 
igneous theory, nor any corroborating fact, but that in 
localities — possibly areas of exceptional volcanic OB chemical 
affinities — an increase of heat, registered by thermometers 
sunk within borings, has been noted at successive depths. 
But heat, so tested, might result from disengagement of 
latent caloric during the friction of the tools used in boring. 
The result of a boring more recently undertaken at St. Louis. 
U. S., to a dejjth exceeding 3,840 feet, contravenes the accu- 
racy of the data assumed from earlier experiments, of a 
relatively proportionate increase of temperature at successive 
depths from the surface, and points to similar conclusions to 
those deduced from deep sea soundings, that, most probably, 
a fixed low temperature is attained at great depths, and 
prevails even equatorially. That a gradual increase of heat 
at descending depths is not the experience of practical miners, 
may be inferred by the fact, that the assumed proportionate 
increase of heat, from the mean quantity deduced by earlier 
experiments, of 87° at the depth of 1740 feet, has not militated 
against the working of the deeper coal mines, by natives of a 
cool climate. The Rose coal mine at luce, near Wigan, pos- 
sesses the deepest known shaft in the world, yet is short of 
half a mile in depth. Poor puny finite man, what data hast 
thou for authoritative assumptions as to the internal struc- 
ture of a globe of which thou canst as yet but scratch the 
