} 
Miscellaneous Notices. 111 
In a former number of the Journal of Science, Prof. Mitchell, has 
given some valuable observations on the Pliocene region of North 
Carolina, in which he favors the theory of an upheave from the ocean, 
which Mr. Lyell has since so successfully applied to all other strata 
embracing fossils of marine origin. 
Arr. X.—Miscellancous Notices ; by Lt. W. W. Bappetey, of the 
Royal Engineers,—Quebec. 
1. On the conjectured buoyancy of boulders at great depths in 
the Ocean. 
To tHe Epiror.—Dear Sir,—Among the many phenomena 
which serve to interest and perplex geological students, none are 
more striking than the formation and position of boulders, and it is 
highly probable that no cause, in the first instance, tends more to 
draw votaries into the labyrinths of this delightful science, than the 
silent eloquence of these mysterious masses. We who reside on 
this new and interesting continent, are particularly liable to have our 
conjectures kept alive respecting them, and it appears to me impos- 
sible to pass one of these travelled rocks, without feelmg the momen- 
tary wish that it possessed the power of speech, and the inclination 
to gratify our natural curiosity concerning them. 
It is not, however, my intention to take up your time with so su- 
perfluous a labor, as the discussion of the well known facts bearing 
upon the inquiry into the cause or causes of the distribution of boul- 
ders would be ; but neglecting these, I wish to call your attention to 
the applicability of a fact to it, which, as far as I am ‘aware, has not 
been pointed out before, in any publication, although I doubt. not 
that it has occurred to many persons. 
As long as it was maintained that water was incompressible, an 
opinion originating in the well known Florentine experiment ; an 
augmentation in the specific gravity of sea water, as the result of pres- 
sure, could not be rendered applicable to the enquiry. But the ef- 
fect of experiments, in recent times, has been to overthrow the Flo- 
rentine doctrine in this respect, and to render it probable that the 
density of water, owing to pressure, increases in a ratio proportioned 
to its depth. 
Now, if this be true, what is the amount of this ratio? Is it suffi- 
cient to give to the waters of the ocean, in their greatest depths, a 
