STEAM COMMUNICATION WITH INDIA. 
55 1 
had been the first who had observed the 
Sharp Fell boulders. These boulders 
Mr. Sedgwick had noticed on the shores 
of the Solway Frith, mixed with gravel 
from Dumfrieshire. He alluded to the 
action of water upon the crests of 
mountains, and to the occurrence of 
transported blocks at considerable ele- 
vations. It was well known that moun- 
tain lakes were gradually filling up ; 
and he had shown in a paper to the 
Geological Society the relation of a lake 
to the age of the valley containing it. 
With the diluvial gravel over the coun- 
try we find the associated organic re- 
mains, — a strong proof that the land 
must have been dry when the transpor- 
tation took place. — Mr. Murchison had 
observed these boulders associated with 
recent shells atvarious elevations, — con- 
sequently, the land must have been at 
one time under the sea, and have been 
subsequently elevated. There must 
have been a relative change of the level 
of land and sea; and Professor Esmark, 
in Norway, had been the originator of 
the idea of the icebergs transporting 
gravel. He referred to the valley of the 
Inn, in the Tyrolese Alps, as illustrat- 
ing this alteration of level : boulders of 
granite had been found on calcareous 
mountains composing one of its sides, 
elevated five or six thousand feet above 
the sea level ; and this valley could not 
have been scooped out. — Dr, Buckland 
was of opinion that the land must have 
been dry before the action of the water 
that had transported these blocks. There 
was a great number of organic remains 
mixed with the gravel, derived from ani- 
mals existing on dry land ; and this was 
not only true in England, but confirm- 
ed by observations in the continent of 
Europe. 
In the Statistical Section, Dr. Lard- 
ner delivered a lecture on Steam Com- 
munication with India — a subject on 
which we have dilated too recently, and 
at too great a length, to return to it in the 
present crowded state of our columns. 
In the Section of Mechanical Science, 
Mr. Whewell gave a short account of 
the present state of the science of the 
Tides. Though there can be no doubt, 
he observed, that the tides are to be 
reckoned among the results of the great 
law of universal gravitation, they differ 
from all the other results of that law in 
this respect, that the facts have not, in 
their details, been reduced to an accord-^ 
ance with the theory ; and the peculiar 
interest of the subject at the present 
moment arises from this, that the resear- 
ches now going on appear to be tending 
to an accordance of theory and observa- 
tion ; although much in the way of cal- 
culation and observation remains to ba 
still effected before this accordance 
reaches its ultimate state of complete- 
ness. With regard to observation, the 
portofBristolofifers peculiar advantages ; 
for, in consequence of the great magni- 
tude of the tides there, almost all the 
peculiarities of the phenomena are mag- 
nified, and may be studied as if under a 
microscope. With regard to the theory, 
one point mainly was dwelt upon. By 
the theory, the tides follow the moon^s 
southings at a certain interval of time, 
(the lunitidal interval,) and this mean 
interval will undergo changes, so as to 
leave less than the mean when the moon 
passes three hours after the sun, equal 
to the mean when the moon passes six 
hours after the sun, and greater than 
the mean when the moon passes nine 
hours after the sun ; and the quantity, 
by which the lunitidal interval is less 
than the mean when the moon is three 
hours after the sun, is exactly equal to 
the quantity by which the lunitidal is 
greater than the mean when the moon 
passes nine hours after the sun. And 
this equality of the defect and excess of 
the interval, at three hours, and at nine 
hours, of the moon’s transit, is still true 
where the moon’s force alters by the al- 
teration of her parallax or declination. 
Now we are to inquire whether this 
equality of excess and defect of the inter- 
val in all changes of declination, &c. is 
exhibited by observation. It appears at 
first sight, that the equality does not 
exist; that is, if we obtain the luniti- 
dal interval by comparing the tide with 
the nearest preceding transit. But, in 
truth, we ought not to refer the tide to 
such a transit, because we know that 
the tide of our shores must be produced 
in a great m.easure by the tide which re- 
volves in the Southern Ocean, and 
which every half day sends off tides 
along the Atlantic. The tide therefore, 
which reaches Bristol, is the result of a 
tide wave, which was produced by the 
action bf the sun and moon at some an- 
terior period. It is found, that if at Bris- 
