570 Reviews—H. Woods’ Elementary Paleontology. 
Barometric changes, for example, exert a very marked and 
nearly, if not quite, immediate influence on the level of water in 
wells, especially those changes which take place suddenly, for the 
effects of long period barometric oscillations may be masked by other 
movements. A rise in the barometer is associated with a fall in 
well-water, and also with a diminution in the rate of flow of water 
from tile-drains, springs, and artesian wells, even from a well 
979 feet deep. Semi-diurnal changes of level are also perceptible, 
a major minimum occurring from 7 to 10 a.m. and a minor one from 
9 to 11 p.m., coinciding therefore in time with the maxima of the 
semi-diurnal barometric period. There appear to be two very 
different causes to which these movements may be attributed— 
(1) The general level of the ground-water may be depressed bodily 
by a rise of barometric pressure, and vice versd, just as would be the 
case with the ocean surface with a change in the distribution of 
pressure. Or (2) when the barometer falls, the expansion of the 
air escaping from the water, and of that which exists in the inter- 
stitial soil-spaces above the ground-water, may force the capillary 
water out into the wells and drainage channels, the rarefaction of 
the soil-air allowing the return of the water into the passage-ways 
when the barometric conditions are reversed. 
Changes in the temperature of the soil also produce changes in 
the level of the water-surface, the surface rising with an increase 
of temperature, and vice versd; possibly in part from the expansion 
and contraction of the air which occupies the capillary spaces of the 
soil. 
Heavily-laden railway-trains passing at a distance of 140 feet 
from one of the wells produced a rapid but gradual rise of the 
water of about =; of an inch, followed by a slightly less rapid fall 
again to the normal level. It is doubtful whether this is due to the 
compression of the earth by the weight of the train and consequent 
lateral displacement of the ground-water, or to the water being 
forced out of the capillary spaces just above the ground-water 
surface. The phenomena may, in any case, have some bearing on 
the movements of water in wells during earthquakes. 
Lastly, these experiments have shown that the general impression 
that water cannot percolate through frozen soil is not quite correct. 
During three consecutive winters, at times of sudden thaws or 
winter rains, water has been observed to find its way through the 
frozen ground, probably by shrinkage cracks and worm burrows, 
into the drains and shallow wells of the experiment farm. 
C. Davison. 
VI.—Eementary Panmonronogy ror GronocicaL SrupENts, by 
Henry Woops, B.A., F.G.S. Small 8vo. pp. vi. and 222, 
with 56 figures in the text. Cambridge Natural Science 
Manuals. Cambridge University Press. (October, 1893.) 
| Riera is deathless; and an educational humorist once remarked 
that each new Text-book was a compilation of the mistakes of 
all its predecessors, with a few added on its own account. We 
