OCTOBER 13, 1899.] 
tention. But the geologists have found no 
such confirmation. On the contrary, they 
have been unable to discover any indication 
that the rate of geological causation has 
ever, on the whole, greatly varied during 
the time which has elapsed since the deposi- 
tion of the oldest stratified rocks. They do 
not assert that there has been no variation, 
that there have been no periods of greater 
activity, both hypogene and epigene. But 
they maintain that the demonstration of the 
existence of such periods has yet to be 
made. They most confidently affirm that 
whatever may have happened in the earliest 
ages, in the whole vast succession of sedi- 
mentary strata nothing has yet been de- 
tected which necessarily demands that more 
violent and rapid action which the physi- 
cists suppose to have been the order of na- 
ture during the past. 
So far as the potent effects of prolonged de- 
nudation permit us to judge, the latest moun- 
tain-upheavals were at least as stupend- 
ous as any of older date whereof the basal 
relics can yet be detected. They seem, in- 
deed, to have been still more gigantic than 
those. It may be doubted, for example, 
whether among the vestiges that remain of 
Mesozoic or Paleozoic mountain-chains any 
instance can be found so colossal as those of 
Tertiary times, such as the Alps. No vol- 
canic eruptions of the older geological pe- 
riods can compare in extent or volume with 
those of Tertiary and recent date. The 
plication and dislocation of the terrestrial 
crust are proportionately as conspicuously 
displayed among the younger as among the 
older formations, though the latter, from 
their greater antiquity, have suffered dur- 
ing a longer time from the renewed disturb- 
ances of successive periods. 
As regards evidence of greater violence 
in the surrounding envelopes of atmosphere 
and ocean, we seek for it in vain among the 
stratified rocks. Among the very oldest 
formations of these islands, the Torridon 
SCIENCE. 
521 
sandstone of North-West Scotland presents 
us with a picture of long-continued sedi- 
mentation, such as may be seen in pro- 
gress now round the shores of many a 
mountain-girdled lake. In that venerable 
deposit, the enclosed pebbles are not mere 
angular blocks and chips, swept by a sud- 
den flood or destructive tide from off the 
surface of the land, and huddled together 
in confused heaps over the floor of the sea. 
They have been rounded and polished by 
the quiet operation of running water, as 
stones are rounded and polished now in the 
channels of brooks or on the shores of lake 
and sea. They have been laid gently down 
above each other, layer over layer, with fine 
sand sifted in between them, and this de- 
position has taken place along shores which, 
though the waters that washed them have 
long since disappeared, can still be followed 
for mile after mile across the mountains and 
glens of the North-West Highlands. So 
tranquil were these waters that their gentle 
currents and oscillations sufficed to ripple 
the sandy floor, to arrange the sediment in 
laminee of current-bedding, and to separate 
the grains of sand according to their rela- 
tive densities. We may even now trace the 
results of these operations in thin darker 
layers and streaks of magnetic iron, zircon, 
and other heavy minerals, which have been 
sorted out from the lighter quartz-grains, as 
layers of iron-sand may be seen sifted to- 
gether by the tide along the upper margins 
of many of our sandy beaches at the present 
day. 
In the same ancient formation there 
oceur also various intercalations of fine 
muddy sediment, so regular in their thin 
alternations, and so hke those of younger 
formations, that we cannot but hope and 
expect that they may eventually yield re- 
mains of organisms which, if found, would 
be the earliest traces of life in Europe. 
It is thus abundantly manifest that even 
in the most ancient of the sedimentary reg- 
