Prof. J. Mil ne — On the Flotation of Icebergs. 
65 
VI. — CONSIDERATIONS ON THE FLOTATION OF ICEBERGS. 
By Professor John Miene, F.G.S., 
Of the Imperial College of Engineering, Jeddo, Japan. 
I N all our text-books of Geology, the action of floatiug Ice is 
referred to as an agent of great power in producing pliysical 
clianges. Its two cbief forras are tliose of Coast Ice and Icebergs. 
Much bas been vvritten about the latter of these, but about the 
fermer very little. In the Georogical Magazine, July, 1876, in an 
article on Ice and Ice-work in Newfoundland, I endeavoured to show 
that the greater agent of the two was Coast Ice, a view which has 
been subsequently r strengthened by observations on the Coast of 
Finland. In this paper I had occasion to refer to the laxity with 
which the conditions under which Icebergs float have been spoken 
about. Thus, in Jukes and Geikie’s Text-Book of Geology, p. 416, 
we are told that because “ about eight times more ice of an iceberg 
is below water than above,” therefore “ a mass which rises 300 feet 
above the waves has its bottom 2400 below them.” 
As no regard is paid to what the relative shape of ice above water 
is to that below, might it not be well to add, in order to render the 
liarmlessness of the doctrine more evident, that the rnere fact of 
planting a Union Jack upon the surnmit of the berg would cause an 
addition to its depth equal to eight times the height of the pole ? 
If this were only done, Icebergs might be talked about as grounding 
in very deep water, where they could “ tear up the softer deposits of 
the sea-bed,” and “ rub down and groove the harder rocks ” to an 
unlimited extent. This grounding in deep water I endeavoured to 
show to be, in the generality of cases, untenable, excepting, perhaps, 
in the case of bergs immediately in the vicinity of their origin, where 
they more or less approximate to parallelopipeds in their form. In 
doing this, I also showed that in consequence of the degrading action 
which takes place, more especially between wind and water, it would 
seem that bergs as they travel towards low latitudes must be looked 
upon as a form more like a peak which Stands upon a sunken 
pedestal or foot, rather than as descending perpendicularly into the 
water. In such a case it is evident that no great depth could be 
obtained. 
However, to take as favourable a view as possible of ice reaching 
down to abyssal depths, I will again assume a case which I took 
before (Geological Magazine, July, 1876, p. 307), where we must 
imagine the portion of the berg beneath the water to be a general 
continuation of that above. 
Such a figure I showed might be regarded as approximately equal 
to a cone or many-sided pyramid. In such a case I have shown 
mathematically that the depth of ice below water is approximately 
equal to the height which is exposed above, the slight difference which 
may exist depending on the ratio we take as existing between the 
specific gravity of ice and sea-water, — a conclusion from which I 
do not see the slightest reason to alter. 
This bcing the case, it consequently follows that if it is accepted 
DECADE II. — VOL. IV. — NO. II. 5 
