Notes from and reflections upon
ICE OR WATER
Another appeal to induction from the scholastic methods of modern geology
by Sir Henry Howorth, K.C.I.E, D.C.L, F.R.S., V.P.S.A., F.G.S., president of the
Royal Archaeological Institute, Author of "the mammoth and the flood", "the glacial nightmare
and the flood", "the history of the mongols", "chinghiz khan and his ancestors," etc,. etc.
Dedicated to the right honourable A. J. Balfour M.P., D.C.L., LL.D., F.R.S.
Some notes and caveats
I have not read all of Howorth by any means. I am not familiar with the terms of debate of his day.
I'm not at all sure that all he says can be taken at face value. Now read on...
The book is supposed to be in 3 volumes (it says so on the front cover of vols I and II). However,
the UL can't find any evidence of vol III ever existing. In the preface, reference is made to
specific chapters in vols I and II, but not to vol III. Vol II terminates with "...ought to throw
some light on the problem of finding a rational explanation of the so-called
glacial phenomena of the temperate zones... to which I hope to turn in the
next chapter". It would seem that he did not have time to do this.
Contents (vol I)
- Astronomical theory of Ball. This theory (astro-only causes of an ice age) is "demolished" on
the grounds that the changes in insolation calculated are too small to do very much. These
grounds are probably fair enough (neglecting all feedbacks, which this chapter does).
[Link here to further discussion of this].
Heavily reliant on arguments such as "no amount of disparity in the
length of the seasons can create an ice age so long as precisely the same heat... reaches the
earth in a year" (p24).
- Theory of Croll. Notes (p39) that Stefans law (recently discovered, and apparently
slowly replacing the earlier assumption of Newtonian (linear) cooling) would imply a
reduction in the effect of increased insolation. This is true by probably trivial over the
range of temperatures considered. (p59: notes that Croll in 1875 could not have known
of Stefan 1879).
Notes Tyndalls etc experiments showing importance of
water vapour to absorption of heat radiation. Appears that Croll knew he needed
feedbacks to get a significant temperature change.
On p58 there is an interesting discussion (to those who have read Fourier 1827) on the
temperature of space.
Quoting Howorth paraphrasing Croll: "Pouillet and Herschel had calculated by different methods
that the temperature of space is -239oF, or 222o higher than absolute zero. As the mean
absolute temperature of the earth is about 521o, he accordingly concludes that the
proportion of heat received from the stars is to that received
from the sun as 222 to 299 [why not 222 to 521?]... Croll ...[says]... that the temperature of
space is not far from absolute zero."
On p67 we seem to meet the ice-albedo feedback for the first time: of the
summits of the Alps, etc, Croll "very justly says,
the greater part of the heat received there is reflected back into space", but apparently this
will not do because "the air there is very dry and very transparent to heat". This seems to be
invalid because it fails to split the radiation into solar (to which the atmos is largely
transparent) and heat (largely absorbed, especially by moist air).
It looks like Croll was arguing for alternation glaciation in opposed hemispheres [??Apparent contradiction: see below??].
Howorth attacks this idea, probably correctly since it isn't true.
There are some attempts at analogies with Mars, which shows variable ice caps. Howorth (and Lowell)
believe these are ice (not CO2, as now known(?)).
- Various theories.
Wallace (Croll plus geographic changes, eg breach of Isthmus of Panama; p93).
Renoir etc (variations in solar output as deduced from changes in subspot number).
- The answer of geology to the astronomical theory of an ice age
Contents (vol II)
- Some a priori Arguments against the great ice age.
Starts off criticising the "epeirogenic" theory, which apparently suggested ice ages
occurred because the affected regions were uplifted, which is easy to defeat. However,
on p5 there is discussion of the evidence of fiords, which his opponents say shows former elevation
of the land, and he dismisses (the fiords are clearly "simply transverse rifts caused
by the elevation of the high lands where they occur"). Was it appreciated that
sea level should be lower in glacial times? Howorth gives no hint of this.
Then we have "transcendental glacial arguments". "When Croll and his followers
talk and write about ice many miles thick as the instrument with which
they would work, they never stop to inquire... the amount of ice which can be piled
up in a heap without causing it to crush". [How thick did Croll think the ice
should be? Ice *does* get 1-2 miles thick so Howorth is wrong here... and, as far
as I can see this is typical of his work, he presents no counter-evidence, just
says, effectively "well I can't imagine this so it must be wrong, guv".]
Follows on with criticism of the interpretation of shropshire permian beds. [When exactly was the
permian? Howorth takes it that the ice ages should have extended into the indefinite past;
was this actually the way the theory was suggested?]
- The biological evidence about the so-called ice age and the question of
interglacial periods. "When Croll formulated the theory by which he made his great
ice age extend over a whole cycle of years, from 240,000 BC to 80,000 BC, he urged that such
an age necessarily included several minor periods involving
alternations of climate, and hence he introduced the notion of interglacial periods.
The notion does not seem to have occurred to geologists before...". [Odd.
I thought that geologists believed in long interglacials with fairly short
"Dr Croll says the glacial epoch may be considered as contemporaneous in both hemispheres,
but the epoch consisted of a sucession of cold and warm periods, the cold periods of
one hemisphere coinciding with the warm periods of the other".
- The alleged southern frontier of the drift beds and the mistaken
inferences based upon it
- The arctic regions in so-called glacial times. Howorth believed that
Greenland and Antarctica were elevated rock covered in snow. He is definitely wrong
in the case of Antarctica (where large portions of the bedrock are below sea level)
and Greenland. Howorth doesn't believe that the polar regions are cold due to insolation:
he argues that the heat of summer compensates for the cold of winter (this is bizarre: in
volume I he has happily quoted tables of figures for insolations in various latitudes
and so ought to be aware that the poles, on average, get less insolation through the
year than the tropics). He quotes Peary saying "The term 'inland ice' suggests ... erroneous ideas.
The surface is not ice, but a compacted snow." He appears to use this to bolster his
claim that Greenland is rock overlaid with snow. Odd.
Theories of the Time
As noted in I&I's book, astronomical theories kept coming and going. In fact, IMHO, astronomical
theories kept coming, got shot to bits, and left again. Not till the accurate dating of deep-sea
cores and the seminal HIS (1976) did they come and stay.
Howorth says (xiv) "In my earlier work I devoted pp. 354-376 ... to ... the astronomical theory ...
which had then been discarded by every notable astronomer, physicist and geologist as
illegitimate. ... the theory was then dead and had not a single champion.
A very potent and uncompromising champion of it appeared ... the Royal Astronomer for Ireland" [Sir R. Ball; 1892].
[Side note: I recently acquired a copy of "In The High Heavens" by
the same Ball, a collection of popular-type articles, chiefly because of
the (now amusing, to those who like to use the vast power of modern science
to look down upon those who lacked it) discussion of the lifetime of the sun].
Howorth is a (self-described) cataclysmism (as opposed to a uniformitarian): he explicitly invokes
"the geological reasoning and hypothesis of an earlier date, in which a cataclysm on a widespread
scale, which caused very important dislocations
of the earths surface accompanied by gigantic tidal waves..." (xi).
Howorth uses colourful language. He prefers to use the term "glacial nightmare" rather than glacial theory.
On p33 he notes that he "ventured to write some strong and perhaps too personal
letters in Nature...". On p li he says "It is not easy to conduct a polemic against a dominant school
of scientific thought... without using some of the energetic adjectives and adverbs which
their attitude has inspired, and which my inherited gout has made rather prolific.
The nature of ice
There is a comment in I&I's book that geologists of the time (mid 19 C?) did not at first appreciate how
ice moves. This is discussed by Howorth (xxxiii-xl). Much of it makes little sense to me, but he
appears to be arguing against the idea that ice can flow (and hence scour/polish). P xxxviii says:
"ice... in a mound, its upper layer will roll over its lower ones until the slope of its surface is
reduced to that of equilibrium(1)...
the motion... is virtually confined to the upper layers...
the lower layers are almost, if not quite, quiescent".
Note (1) is: "Here, again, Sir R. Ball is most cryptic and enigmatic
in his language. What can he mean when he speaks of 'the glacial sheet becoming gradually thicker until
the pressure of the superincumbent masss forces the subjacent layers into tardy motion'?".
Glaciology nowadays would agree with Ball.
See also notes above re ice thickness.
V 1.0.1, 2003/05/02