From Duncan Steel <>

Dear Benny,

Having read some of the comments of others, I now have some further
comments with regard to Timo Niroma's ideas regarding events around
1867. In some ways my calendrical comments may appear off-topic, but I
note that they relate not only to some statements of others, but
also pertain to the general notion of identifying exceptional events.

There were two main subjects which Timo addressed: (A) The climate in
Helsinki around that time; (B) A flood of the Nepean river, near
Sydney, ditto. I will deal with those in turn although my comments
are related.

(A) In retorspect some of my initial statements about the effect of the
calendar followed in Finland could have been better-expressed, but the
gist of my intended meaning still applies. That is, in making any
comparison like this one has to be *very careful* about the calendar
and time-keeping systems followed. If Finland took records internally
and maintained them that way on a calendar which is consistent with
respect that widely used now then that provides some advantages, although
there are still many problems which I come to below. On the other hand,
one must be careful that the records have not been passed through some
filter, such as a conversion to another calendar (like that used in
Russia or elsewhere). One example of the problems which can crop up
in that way is that if weekly-averaged maximum temperatures were kept,
then in converting (at any stage before 1st March 2100) from the Julian
calendar to the Western calendar a hiccup will occur because the number of
days in the correction is not divisible by seven.  Let me refer the
reader, for example, to the paper by D.J. Thompson in Science, 7 April
1995.  I will come back to that paper later.

Having written that, in terms of increasing complexity I would mention
the following problems with the comparison between monthly temperatures
which Niroma describes:

(i) What temperatures do you use?  Do you employ a maximum and minimum
scheme? That will lose the temperature averaged over the day.  Do you
use a temperature at a certain time of day? If so, do you use local
solar time, local mean solar time, or standard time?  (Prior to the
International Meridian Conference in 1884, the records of that meeting
indicate that only four nations followed standard time systems: the UK,
the USA and Canada - but only just for those two, from the year before -
and Sweden; was Finland on standard time?  The Netherlands did not become
part of the international standard time system until 1954, for example).
Just how does one compare temperatures from 1867 with those measured
now, then?

(ii) The idea of "the coldest/hottest month on record" is fraught with
drawbacks and inadequacies.  Although it is the sort of phrase trotted
out by TV weather presenters all the time, it has little scientific
validity.  This is for a number of reasons, the first of which is
simply that calendar months are not the same length.  January has
more chances to get the 'coldest day' than February.

(iii) The second problem is that even if you compare same-length months
(compare all months labelled 'January') there is still a problem, because
those labels do not refer to a constant time of seasonal year (but see
below too).  With the leap year scheme used in the Western calendar the
time of the vernal equinox ranges over 53 hours within 19-21 March,
producing a corresponding variation in the solar longitudes at which
'January' occurs.

(iv) It has been assumed for a long time that the seasonal year follows
the spacing between the equinoxes and solstices, the *average* such time
being the familiar *tropical year* of 365.2422 days when again averaged over
some dozens of orbits.  This assumption seems to be wrong.  The
publication by Thompson referenced above shows that the cycle time of
the seasons over the past several centuries (since temperature records
began) is actually the anomalistic year, the time between perihelion
passages, which is near 365.2596 days again when suitably averaged.
Because perihelion passage shifts later by about one day every 58 years
on the Western calendar, this would imply that not only does 'January'
oscillate by 53 hours in the leap year cycle, but also the current
'January' is shifted, seasonally-speaking, by more than two days
compared to 'January' back in 1867.

There are other more-detailed comments I could make, but the above should
be sufficient to show some of the specific reasons why I have doubts
about the idea of using the concept of "the hottest/coldest January on
record" or somesuch as being a sure-fire indicator of some drastic
effect.  On the other hand, if there is a clear anomalous drop of
the max and min temperatures by many degrees persisting for some time
then one might suspect that *something* was going on, but the analysis
of past records must be done judiciously and with much double-checking
and consideration of the meaning of all the parameters, like the dates.

(B) Superlatives make the news, which is why TV weather people make
statements like that above.  But that does necessarily not make the
phenomena truly exceptional.  If you look at one of the year books
beloved of American High School classes, every student is given a
positive superlative in some respect (the dumbest kid in the class is
"The student most likely to improve").  Would one count a particular
class as being the 'tallest in the state' because it produces two
champion basketball players?  If you take several hundred
separated towns, spread around the globe, it is near certain that two
or more of them will have on any set day the hottest/coldest/windiest/
wettest day of the year (similarly week/month/season/year).  That does
not mean that the climate has gone haywire and an asteroid has hit us.

Exceptional weather is very common, then. Various Australian
correspondents have already commented upon the apparent Nepean River
flood in 1867, and their statements are wise and knowledgeable.  Even
back then this was a densely-populated region, a fertile well-watered
region with a navigable river and an excellent sea-harbour nearby.
Quite likely there have been Tunguska-type events in recent centuries in
unpopulated regions which have escaped notice in the 'civilized world',
but this was not one.

People living in one part of the world will have experiences of the
phenomena all called 'floods' which are quite different.  As a boy in
England, persistent heavy rain for some hours would occasionally flood
the small river passing through my home town, leaving the shops full
of smelly mud.  In southern Arizona, the dry desert is prone to flash
floods which thunder down through chasms cut through the parched land
and drown people, with not even a few minutes' warning.  If you drive
through Nyngan, in dead-flat outback NSW, you will notice in the arid
surrounds of the town large noticeboards thanking others for their help
in the aftermath of the great flood of 1990.  Outback NSW is almost
always dry, but it is one big flood plain.  Last year the town of
Katherine in the Northern Territory was submerged.  Exceptional events,
but they happen somewhere in Australia every year.  Note that, if you
are habituated to floods being sudden, this is not necessarily the
case in a large flat continent.  Heavy rain up in Queensland a couple
of years back produced a low wall of water hundreds of km wide which
eventually flooded the dry salt lakes of South Australia, for only the
fourth or fifth time since European colonization began, bringing in birds
from far away and making the desert burst into flower.  People flocked
from all over to see it: but they had six or eight weeks' warning, because
that's how long the wall of water took to reach the lakes.  You could
have walked ahead of it.  Not all floods are like one imagines based
on one's own peculiar experience.

It is easy to see that correlations between exceptional events occur from
time to time simply by chance. I write this on January 31st, Australian
time.  It is not yet the 31st in the USA.  On this date the Superbowl
will be contested in Miami. If Atlanta beat Denver, it will be an
exceptional event.  Is there a climate connection?  Well, the weather
in Atlanta at this time of year is MUCH more like Miami than is the
case of Denver, giving the former an advantage (although I tend to think
that if the Falcons triumph it will be for other reasons).  Somewhere in
North America this will quite possibly be the coldest/warmest/wettest...
January 31st on record.

But so what?  Apart from anything else, if one kept a calendar held steady
against the perihelion position (and hence the seasonal cycle *at
present* - I would anticipate that this cyclicity is only temporary for
some centuries until perihelion moves far enough away from the winter
solstice to lose the resonance) then the 24-hour period labelled 'January
31st (Eastern Standard Time)' would in the past have been in February.

This all comes back to the calendar one uses.  Above I have employed the
term 'Western calendar', as indeed has Arthur C. Clarke in an item cited
earlier in a CC Digest.  May I recommend its usage to everyone. It is
a fallacy that the calendar used as the world-wide standard (with local
or religious calendars also employed) is the 'Gregorian calendar.' That
is an ecclesiastical calendar adopted by-and-large only in various
Catholic states around 1582-1610, persisting since in e.g. Italy and
Spain.  Elsewhere solar calendars have been legally adopted (by other
countries) in which the same (inaccurate) leap year rule as the Gregorian
happens to be used.  The Western calendar derives basically through the
major powers: Britain's calendar reform of 1751, which was inherited by
the American colonies and thence by the initial founding states of the
USA (note that the USA does not have any legal calendar code of its own,
the familiar system is just used by common assent there and hence
elsewhere).  It is this which may be termed the 'Western calendar'.

But that does not make the Western calendar the same as the Gregorian.
There are several very significant differences.  The Gregorian is a
luni-solar calendar in that it provides for a lunar cycle as well as
a solar sycle.  Everyone knows about the leap-year corrections (three
in 400 are dropped: 1700, 1800, 1900, 2100...) but few know also of
the lunar jumps: the lunar phase (the phase of the ecclesiastical moon,
not the real moon) is assumed to follow the Metonic cycle of 19 years
which is close to 235 lunations, except that over a period of 2500 years
there are eight single-day jumps interposed.  This is done to 'regularize'
the date of Easter, the main aim of the Gregorian reform.  The
Gregorian is a luni-solar religious calendar, whereas the Western is a solar
civil calendar.  They are not the same thing.

That is not to say that Lord Chesterfield's Act of 1751 did not address
religious matters.  It had to, because Great Britain (as it was then)
is a religion-based nation.  The monarch is the 'Defender of the Faith.'
In this connection the Act contains several mistakes.  For anti-Catholic
and anti-Semitic reasons the phraseology employed (oft-quoted by people in
some form : "Easter is the first Sunday after the first full moon after the
equinox") is nonsensical in itself, and does not lead to the Easter dates
actually printed in the Book of Common Prayer, the tables there following
the Catholic rules.  The statement cited there would imply that Easter
cannot coincide with either an astronomical full moon or the Passover,
whereas such coincidences do occur.  I might note that the first person
to have spelled out this nonsense, in about 1850, seems to have been
Augustus De Morgan, one-time Secretary of the Royal Astronomical Society.

On top of that - and this is significant - the Act mentions the desire to
keep the solstices and equinox at the same seasonal dates.  Leaving aside
the recently-recognized fact that the seasons follow the anomalistic year,
the implied necessary year-length for the calendar (the Western) as defined
by that Act is the *tropical year* of 365.2422 days (on average, etc.).
The 'Explanatory Supplement to the Astronomical Almanac' (an official
publication of the US & UK governments) actually mis-defines the tropical
year as the time between vernal equinoxes, and it is NOT.  Because of the
eccentricity of our orbit four different-length years result from the
times between vernal and autumnal equinoxes, and winter and summer
solstices.  The Gregorian reform was based upon regularizing Easter and
thus keeping the date of the vernal equinox near-constant (which it fails to
do; note the 53-hour range mentioned earlier), meaning that the year
counted between those equinoxes is what is needed.  This is 365.2424 days
at present.

This provides another reason why the Gregorian and Western calendars
are not the same thing: their target year lengths are different.  That
difference in the fourth decimal place is significant.  The mean
Gregorian year of 365.2425 days is much closer to the Vernal Equinox
year of 365.2424 days than the tropical year of 365.2422 days, as used
in the Western calendar. Arguments over whether we need a 'correction'
every 3200 or 4000 years, begun by astronomer John Herschel in 1828,
are thus specious (and apart from anything else, tidal drag is
lengthening the day as defined astronomically as opposed to
atomically). The Catholic Church in the later sixteenth century would
have produced a 'better' calendar if it had instead used a 33-year
cycle containing eight leap years, as does the Persian calendar.  This
(i) Makes a year 365.242424... days long on average; (ii) Makes a cycle
short enough to keep the equinox within a 24-hour range; (iii) Leads to
a better solution of the lunar phase problem connected with Easter.

There is more.  The Eastern Orthodox Churches have suffered splits
since in 1923 it was suggested that they alter from the Julian calendar
to what has been called the 'Revised Julian'.  This would have seven
leap year days dropped from nine centuries, such that the year would
average to 365.242222... days.  This was to provide one-upmanship over
the Gregorian scheme, but it is based on the mistaken belief that the
*tropical year* rather than the *vernal equinox year* is the target.
There are still arguments within those Churches on this topic, mostly
based on a totally incorrect understanding of the astronomy.

But this brings me full circle.  So far as I am aware the only one of
the Orthodox Churches to have adopted the Gregorian calendar is that of
Finland. Thus it is true that the Gregorian calendar is used in
Finland: within the Orthodox Church, and the Catholic Church.  As for
the rest of the country, that is a different matter.  One would need to
look at the Swedish legislation to see whether they adopted the
Gregorian calendar, in a legal act dated (I would imagine) 1752, the
year before the actual reform took place, although I am not sure
whether Sweden was using the March 25th New Year as was Britain until
31st December 1751.  I would imagine that the Lutherans of Sweden, like
the Anglicans of Britain, would have written an Act which did not
mention the Catholic Church/Pope etc., but rather defined a parallel
solar calendar with some definition for when Easter is to be
celebrated.  Perhaps they made the same silly (and
religiously-motivated) mistakes as did the British.

It is very easy to make glib statements like "We use the Gregorian
calendar" without realizing what is actually involved.  For example,
making January 1st the New Year's Day is often ascribed to the Gregorian
reform, but that is a false belief.  It was already in use before that.
Off and on it has been used since at least 153 BC.  Similarly we use
calendar months which have been unaltered since 45 BC, notwithstanding
claims that Augustus Caesar fiddled with them.  Thus the months, as such,
are not defined as part of the Gregorian calendar.

This links to some rather unwise statements made on this list regarding
the year numbering system which we use.  So many comments are made, in
newsmedia articles and so on, along the lines of 'people in the past
did not know of the number zero' that perhaps I should not be surprised
by the idea being repeated by educated people.  But it really is a
misguided notion.

Our year numbers are ordinals, not cardinals. Notwithstanding the fact
that we count a 'zeroth law of thermodynamics', and a 'zeroth'
Pharaonic dynasty in Egypt, it makes little sense to have a 'zeroth
year'. AD 1 is 'the first year of the Lord'.  (1 BC is the 'first year
Before Christ', a seventeenth-century invention by an astronomer, by
the way.) One may wonder how AD 1 can be 'the first year of the Lord'
if he was born on December 25th (I am talking here about *traditional*
dates rather than historically-veracious dates).  When Dionysius
Exiguus was setting up his framework for Easter dates in 525-253 (he
was not trying to define an era) he correctly recognized that a Jewish
boy's life is reckoned from his circumcision, not from birth.  Thus
Dionysius equated 1st January (in the year which two centuries later
became labelled AD 1) as the date of the circumcision, it being the
start of the year. (Look into a Church Missal and you will find January
1st named as the Feast of the Circumcision, and our method of counting
years from that date is technically referred to as the *Stylo
Circumcisionis*.) Circumcision occurs on the eighth day counting
exclusively (see your Bible), putting the traditional Nativity on 25th
December 1 BC, which was the traditional (but not actual, even then)
date of the winter solstice festivities. (The early Church had actually
used January 6th, Epiphany, to avoid the pagan solstice celebrations.)
Dionysius then counted back the nine month gestation period to the
traditional (but not actual) vernal equinox of March 25th in 1 BC, and
he counted years from there as the *Anni ab Incarnatione*. This is the
year which astronomers call 0 (using cardinals) but is more generally
termed 1 BC (using ordinals).  The fact that March 25th was the
Incarnation/Annunciation/Lady Day was what led to the British and
eventually American colonies using that date for New Year, although
counted FROM THE WRONG YEAR! (AD 1 instead of 1 BC).

I hope that the above is both of interest and illuminating.  A final
note for readers in the USA. Although you now use the Western calendar,
and previous to 1752 the Julian was used in the Atlantic colonies, do
not imagine that no use has ever been made of other systems.  When the
first Catholic missionaries arrived, they imposed the Gregorian
calendar. Thus when (say) Texas and California joined the USA, although
their dating systems may have been continuous they did move from the
Gregorian to the Western calendar. Those parts in the Louisiana
Purchase were on the Gregorian until they were administered for three
weeks under the French Revolutionary Calendar in late 1803, before
Napoleon sold the region to the USA.  That's something to note next
time you eat Lobster Thermidor in New Orleans.

And a final link to the 1860s and the problem of dates.  Until Alaska
was sold in 1868 to the USA it was part of the Russian Empire, and thus
on the Julian calendar.  But it is more confusing than that.  The day
of the week there was different to that throughout the rest of North
America. Although a change from Julian to Western (or Gregorian)
calendar did not involve a change in the day of week sequence
elsewhere, in Alaska it did because that region, in the absence of any
International Date Line, used both the date and the day of the week
appropriate for Moscow.

Perhaps all of the above makes clear why I have cautioned about why
making use of old temperature (or whatever) records has numerous

Duncan Steel


Dear Benny,

Duncan Steel has commented lengthy my comments on the Finnish calendar or
calendar in general versus Finnish measurements on temperatures or the
measurements in general. He makes some interesting points, although the
main idea of the anomalies of the middle 1860's is not considered.

(A) First of all Finland took the records "internally" based on the
autonomy of Helsinki University which based on the autonomy of Finland.
There was no conversion between calendars (unless someone in Russia used
the records for his own purposes). I have not used any weekly-averaged
temperatures, I have used monthly averages based on daily averages.

(i) The daily averages is the mean of the temperatures at 03:00, 09:00,
15:00 and 21:00. Standard time was used in all official places, such as
Helsinki University.

(ii) Of course the different lengths of various months cause some
inaccuracy. So causes also the dividing of the year artificially into
months. But I still think that if there are such anomalies as the May 1867,
several degrees Celsius below the second coldest May in 170 years or even
in Mays of 1866 and 1868 (1.8 degrees C compared to 5.7 degrees on previous
and 8.4 degrees on the next May), this is so great a deviation that it is
not explainable by any artificial errors. The ensuing famine, the hardest
in Finland for 300 years, was also a mark of something very unusual.
(Besides France lost its vine harvest in 1867, so this was not wholly a
Finnish event.)

(iii) What comes to the leap years, the above-said concerns them also. One
day's oscillation drowns in the noise. I really am not supposing that the
1.8 degrees C is absolute, by using artificially months of the same
lengths, or by any other method, the value could have been 1.7 or 1.9
degrees, what matters is that it still is nearly 3 degrees colder than the
next colder May during the last 170 years. And the grave consequences.

(iv) Although April and June 1867 were not record-cold, they still were
well below the normal, April -1.1 degrees C and June 12.2 degrees C, well
below the normal values (the before and after-values of 1866 and 1868 were
pretty normal: April 2.2 and 1.5 degrees and June 15.2 and 13.1 degrees).
So we get for the whole season from April to June for 3 month average:
1866 7.7 degrees C
1867 4.3 degrees C
1868 7.7 degrees C

1. No measurement inaccuracy can't explain this anomaly.
2. The anomaly is so great that an explanation is badly needed.
3. The French events hint that this was a European, not only a Scandinavian
event, and leaves open the question of its global character.
4. The famine was so severe that we could cry for an explanation without
even any accurate temperature measurements.

(B) I don't claim that the Nepean event had anything to do with this. I
only ask could it have had some relation? A tsunami caused by an impacting
body is just a guess. It could have happened far from Nepean, but Nepean
being a lowland it could have suffered even from an impact 1000 km away. Of
course a blanket from a volcano could be as good an explanation for the
anomalious cold in Finland/Europe, but was there any great volcano eruption
in late 1866 or early 1867. I know of no one. Or did something anomalous
happen to Sun in April-May 1867? Or did Earth dive in a cosmic dust,
whatever its source.

I insist that we have here an event that cries for an explanation.

Timo Niroma


Not to drift too far from the subject of Duncan's essay, it is sometimes possible to correlate different time reckoning systems by looking for references to exceptional events LIKE THE 1866 LEONIDS. 

A good source for ferreting unusual events by date is the work of William R. Corliss.  The more recent volumes of his SOURCE BOOK PROJECT include a Time-of-Event index that can be quite helpful in finding possible causes of curious anomalies. 

In THE SUN AND SOLAR SYSTEM DEBRIS (Corliss 1986) the TOE-index for 1866/67 points to:

AYO8X1.  November 13, 1866. England.  "During the great display of Leonids, 1866, Nov. 13, many observers noted nebulous meteor clouds in and around the radiant area.  These appearances were described as greenish ill-defined spots of nebulosity, which brightened and faded." (R3)  Since motion of the nebulous spots is not mentioned, they may be only meteor trails seen head on. (WRC)
(R3)= Packer, David E.; "Nebulous Meteors," ENGLISH MECHANIC, 74:133, 1901.
(WRC)= A comment by Corliss.

AEXIX50.  1867.  A noncircular object, as black as the center of a sunspot crossed the sun west-to-east.
(R17)=  "Astronomical," ENGLISH MECHANIC, 6:129, 1867.

ASO2X3.  East-west coronas.  During the total eclipse of 1867, a period of minimum sunspot numbers, Grosch saw long extensions of faint illumination emanating from the sun's equator, but only very short ones in the polar regions.  (R4)  Some of the observers of the 1878 eclipse saw an east-west corona; others did not. […] 1878 was also a time of sunspot minimum. (R4)
(R4)=  Young, C.A.; "The Corona," THE SUN, New York, 1896, p. 238.

Now whether any of these happenings affected the weather is obviously not known--such observations do supply good food for thought though.  Let's hope the 1866 roar of those Little-Leonids didn't add up to a lingering solar shade--we don't need more anticipated Y2K problems, particularly real ones!  8^/  

Source for SOURCE BOOKS:


Bob Kobres
Main Library
University of Georgia
Athens, GA  30602

CCCMENU CCC for 1999