Kev. J. Brodie on Level Terraces. 
341 
deposit that may there be thrown up must be proportion- 
ably higher. We further find that, in creeks and estuaries, 
which gradually become narrower as they run up into the 
land, the tide, especially in storms, rises higher and higher 
as the channel becomes more and more confined. The Bay 
of Fundy, on the coast of America, where the tide rises and 
falls fully 40 feet, is an illustration of this remark. The 
Sol way Firth, with its peculiarly rapid tide, may be referred 
to as another. The ordinary height of the terrace on those 
parts of the coast which are not exposed to any great 
violence of tempest, seems to be from 5 to 15 feet above 
high-water mark, which is the height to which a full tide 
wave will be driven by a storm. At the head of estuaries, 
it appears formerly to liave been some 5 to 10 feet higher, 
while a still greater elevation may be expected in those 
creeks and inlets which are exposed to the billows of the 
Western Ocean. 
Inferences to be drawn from these Investigations. 
The inferences which we draw from these investigations 
into the action of the natural agencies by which level ter- 
races are produced, may be stated in three propositions : — 
1. While these terraces were in course of formation, the re- 
lative height of the land and water must have remained 
unchanged. So long as the high-water mark continues 
stationary, whatever addition may year by year be made to 
the shore, the height to which the mud or shingle is carried 
will remain the same ; but if, year by year, the land rises, 
and consequently the high- water mark descends, so, in like 
manner, will the comparative height to which the mud or 
shingle is carried be diminished. A continuous upheaval 
of any portion of the sea-shore must therefore produce, not 
a level terrace, but a uniformly sloping bank. 2. Similar 
arguments serve to show that if the land, after remaining 
stationary for a time, during which the level terrace has 
been formed, begins continuously to rise, the terrace will 
not terminate abruptly, but in a gentle, uniform descent. 
3. If any portion of the earth's surface has been raised 
above its former level, the manner in which the elevations 
