70 MONTHLY WEATHER- REVIEW. FEBRUARY, 1901
ology in Belgium by J. Viucent, meteorologist a t the ObEerVa-
tory, which coiitains exhaustive references to the literature of
the subject, begiiining in fact with Charlemagne, who pro-
mulgated and established the use of twelve compass pointe
iuetead of the sixteen now used in the notation of the wiuds,
viz, east, east by south, south by east, south, south by west,
west by south, west, west by north, north by west, north,
north by east, east by north, all which were sometimes known
as the twelve apostles.
The most aucieiit name that can actually be cited in me-
teorological matters is Thomas of Cantimprd, who was born
in Brabant in the early part of the thirteeuth century and
was the author of the work Die Naturis Rerum, which was
finished about 1850 and often attributed to Albert the Great.
The history of modern scientific meteorology in Belgium be-
giiis with Simon Ste'vin, horn a t Brussels in 1648 and died
in Holland in 1620. Hie ideas as to gravity, hydrostatics,
the fall of heavy bodies, the weight of the air seem to have
been quite correct. He first gave two methods for determin-
ing the elevatioiis of the clouds. In one method, assuniing
that the cloud is isolated in the sky and almost stationary,
he measures the angular altitude of the cloud aiid takes a
correspondiug measure of the locntion of its shadow on the
ground. I u the secoud method he makes two 'measures of
the angular altitude, from the extremities of a base line,
the cloud being near the zenith. His ideas on geology aiid
other branches of science were generally clear and correct.
In Girard'a translatiou of the works of Ste'vin he interpoiatea
ideas of his own, such as the vesicular theory of cloud parti-
cles which was not at all known to StBvin. To another
Belgiaii meteorologist, F. d' Aiguillon, born a t Brussels in 1556, we owe the methods of projectiou knowu as ortho-
graphic, stereographic, and scenographic, as well as investiga- tions into the optical phenomeiia of the atmosphere. Of
later authors Fromoiidus (or Libert Froidmont), Fienus (or
Feyenes), Vendelinus (or Weudelin). F. Linus (or F. Hall),
Sluse (or R. F. Walter), L. Gobart, F. Verbiest, J. A. Browu,
(born in 1702, died in 1768) are especially mentioned.
A chapter is devoted to the earthquakes observed in
Belgium, of which the earliest occurred in the year 330, and
the next in 502, but of course only prominent, destructive
quakes are inentioiied in the early records. A t the present
' tinie every tremor is recorded by self-registering apparatus
aud the periodicities, both diurnal and anuual, seem to be
present. After a section devoted to fundaniental nieteorological data
aiid tables of reduction, the Anmaire gives an elaborate ac-
count of two aiicietit nieteorological journals, one relating
to the period 177&ISLO, 'the other to the period 1807-1850.
This is followed by a11 article on the climate of Ardenue,
written at the request of the Belgian Department of Agricul-
ture. These and several essays together make the Aiiiiuaire
for 1901 an interestiiig contribution to meteorology.
OFFICIAL STANDARD TIME.
In the Astronomical Aunual for 1901 of the Royal Observa-
tory of Belgium, the director, Dr. L. Niesten, says that-
I n the astronomical annals we shall continue to make use of local meantime until that very desirable epoch when astronomers shall agree to substitute civil time for it.
Civil time begiiis at midnight, aiid should he cotiiited 011-
ward for twenty-four hours ; astronomical time begins at
noon, and is couiited onward for twenty-four hours.
Official time in Belgium is the civil time for the meridinn
- of Greenwich. This is the legal time used by goverumerit
. officials, railroads, and post offices, and may be called public
or popular time. The legal time in other countries is stated
by Dr. Niesten, 011 page 159 of this Annuaire, to be as follows:
Western European time) or the civil time of t h e Greenwich meridian, is legal in England, Belgium, Holland, and Luxemburg. I n Belgium t h e 34-hour notation has been used since May. 1897, in t h e post office, telegraph, and telephone departments, as also by the railroads and the navy. Central European, or one hour eastof Greenwich, is legal in Germany, Austria-Hungary, Bosnia, and Herzegovina, the Congo Free State, Den- mark, Italy, Servia, Sweden, Norway, and Switzerland. I n Italy the hours are counted from midnight on to twenty-four. The meridian of one hour thirty minutes east of Greenwich is adopted by the railroads and telegraphs in Cape Colony. Eastern ISuropean time, or t h e meridian of two hours east of Green- wich, is adopted by Bulgaria, Roumania, and Natal, and by tlie rail- roads of Turkey in Europe. The meridian of eight hours east of Greenwich is adopted by West Australia. The meridian of nine hours west of Greenwich is adopted by Central Australia and by Japan. The meridian of ten hours east has been adopted by Victoria, Queens- land, and Tasmania. The meridian of eleven and a half hours has been adopted by New Zealand. As is well known. Canada and t h e United States and Mexico have adopted as standarri hours the fifth, sixth, seventh, anil eighth west of Greenwich. I n Canada t h e notation from zero to twenty-four continu- ously has also been authorized. The %-hour notat.ion has also been int.roduced into t h e railroads of British India, where the fifth and sixth hours east of Grtnenwich are commonly used as standard meridians. The eighth hour east of Greenwich would be appropriate to the Philippines, but w e do not know that the American authorities have issued any regulations bearing on this point. The Hawaiian Islands adopt the nieridian of ten anil a half hours west of Greenwich. The nations that have not adopted the Greenwich system are as follows :
I n Spain the legal hour is that of t h e nieridian of Madrid, or 14m 458
west of Greenwich ; in Spain t h e %-hour enumeration has lately been adopted. Portugal adopts the time of the nieridian of Lisbon, or 36m 396 west of Greenwich. Ruwia adopts the meridian of St. Petersburg uniformly for its who!e domain, or 2h. lm. 13s. east of Greenwich.
The above data may differ slightly from that published
elsewhere. In fact, it is difficult to gather correct statistics
for all parts of the world, and the Editor will be pleased to
publish any corrections or additions to this list.
It is iniportarit to bear these standards iu mind when one
wishes to compare the exact time of occurrence of any event
that is observed in two different couotriee. We recall vividly
a remarkable discrepancy in the hourly temperature records
kept iu a certain hospital where the morning readings n'ere
made by a subordinate who happened to be a Freiichman, and
tlie afternoon readings by one who happened to be a German.
The thermometer was unfortunately graduated in the Ceuti-
grade system ou oiie side and the Re'aumur system 011 the
other. As a matter of course, the morning records were kept
in the former and the afteruoon records by the latter system.
Nothing was said about this in the published records, and i t
took the Editor a long time to ferret out the cause of the dis-
crepancies. Doubtless, analogous discrepaucies are introduced
every day by the diflerences between sun time, local mean time, aiid legal standard time. In proportion as we progress
toward one absolutely uniform standard of time, such as
Greenwich, we shall eradicate discrepancies and increase the
accuracy of all work in terrestrial physics.
THE WORK OF THE METEOROLOGICAL INSTITUTE OF
PRUSSIA.
The Meteorological Institute of the Kingdom of Prussia,
(6. Preussische Meteorologieche Institut), directed by Dr. voti
Bezold, includes: (1) The Central Institut of Berlin, divided
into four sections: (f a ) Climatology aiid miscellaneous; (b )
atmospheric precipitation and library : (c ) storms, accideutnl
atmospheric phenomena and iiistrun~eute ; (a ) aeronautics ;
FEBRUARY, 1901. MONTHLY WEATHER REVIEW. 71
(2) Obeervatory of Potsdam of which Dr. Sprung is director,
including two sections ; (a) meteorology and terrestrial mag
netism; (3) 202 stations, of which 148 are in Prussia (123
first and second order, 71 third, and 8 fourth order).
In the course of the year 1899 the number of rainfall sta-
tions was increased by 70. January 1, 1900, i t was raised to
2,315, including the 202 meteorological stations just men-
tioned. The study of atmospheric precipitation is of great
practical importance; i t interests agriculture as well as indus-
try: now that the rivers have again become very important
mediums of transportation and that they are the sources of
energy, i t is of the utmost importance to be acquainted with
their regimen and their sources of supply.
In this same train of thought the Meteorological Institute
of Prussia carried on in December, 1899, observations of the
depth of snow on the grouud a11d its equivalent in water,
and established a service of forecasts bearing on this subject.
Thus, December 19, it was able to send to the hydrographic
services of the five great rivers of Germany dispatches indi-
cating the depth of the snow in the five basins, observed the
day before a t 7 a.m. The geographers and the meteorologists
can refer for details to the weekly reports as to the depth of
snow on ground in north Germany.
The annual report of the Royal Meteorological Iustitute of
Pciissia contains the list of the publications issued either by
this scientific establishmelit or by its colaborers.
TEMPERATURE OF DEEP LAKES.
I n the MONTHLY WEATHER REVIEW for 1595, page 167, we
have mentioned the thermophone devised by H. C. Warren
and G. C. Whipple, and first described by them in the Tech- nology Quarterly, 1895, Vol. VIII, pages 25-152. A previous
elaborate paper by Prof. W. R. Nichols was read in 1850 be-
fore the Boston Society of Natural History. Observations
relating to Clear Lake, N. B., were made by Prof. W. F.
Ganong of Smith College, Northampton, Mass., but those
made by the inventors and Mr. Deemond Fitzgerald in Lake
Cocliituate were more elaborate and established the great
value of this apparatus. Previous to that time the deep sea
thermometers of Negrelti and Zambra or Casella were the
beet available. H. B. de Saussure used in Switzerland an
ordinary thermometer so protected that it could be hauled
up a thousand feet withont changing its temperature lo cen-
tigrade. A series of observatione by the older methods had
been carried on for five years by Mr. Fitzgerald before the
thermophone became available ; the resiilts of both eeries
mutually confirm each other. A similar series was observed
a t Lake Winnepesankee and several other lakes or reservoirs
and the general resul te of both American and European ob-
servations are given in the paper by Fitzgerald published in
the Transactions of the American Society of Civil Engineers,
Vol. SSXIV, pages 67-114.
In general, Mr. Fitzgerald showed that there is an annual
inversion of the vertical circulation in a fresh water pond,
by reason of which when in winter time the lowest portions
begin to cool below 39O Fahrenheit or 4O centigrade thoy rise
because of their diminishing specific gravity and bring u p
the products of decaying vegetation.
I n a shallow lake, such as the reservoir, this circulation
produces an appreciahle diacoloration and contamination of
the upper water at certain seasons ; it is therefore a matter to
be considered in connectiolr with the supply of fresh drinking
water for a city. On the other hand, the study of tempera-
tures in very large natural lakes is a matter of scientific
inquiry leading to important results in connection with the
temperature of the air and the occurrence of fog, cloud, and
rain, the melting of ice floes, to say nothing of the distribu-
tion of fish and marine plants; i t may also have a bearing
on other questions not yet fully appreciated. The most
recent contribution to the subject is a study of the tempera-
tures of Lake Ladoga, which is the largest and one of the
deepest bodies of fresh water in Europe. The Editor would,
however, suggest that possibly the lower portions of Lake
Ladoga are salt water, just as in case of some lakes near Bos- toil which apparently owe their origin to a glacial process
similar to that which gave rise to Lake Ladoga. In the Paris
Comptes Rendus for June, 1900, Lieut. Jules de Schokalsky
of the Russian Navy, published a map of -Lake Ladoga and
the results of his own examination of its temperature for
the years 1897-99. As similar iuvestigations should un-
doubtedly be made on our great American lakes we reprint
this article ; evidently the thermophone will do the work more
satisfactorily than the " upset thermometer."-ED.
ICE CAVES.
On a preceding page we print a short account of the ice
cave a t Flagstaff, Ariz. There are many well-known cases
in which glacial ice has been covered by earth to such a depth
that i t has been preserved for thousands of years, and the
caves or wells penetrstiiig therein preserve a temperature of
32O throughout the year. These, however, represent a very
different phenomenon from that reported by Mrs. Renoe. In
the ice cave at Flagstaff we have probably nothing to do
with glacial ice; the ice is evidently formed annually within
the cave and on the surfaces of its crevices. The ground
around the caves can not have a temperature below that of
freezing. The air temperatures at Flngstaff duriug December,
January, and February frequently fall below freezing, and
this wave of cold will penetrate many feet into the earth by
the middle of summer, but this af itself would only give a low
temperature in the ice caves and would not sufflce to explain
the formation of such niasses of ice. It merely shows why
the water percolating slowly into the caves must be of a low
temperature. If there be a gentle circulation of the air going
on, there must be a corresponding evaporation of a portion
of this water, which will, of course, reduce the tempera-
ture still lower. Now, the dryness of the air a t Flagstaff
is often such that the teniperature of the wet bulb ther-
mometer is below freezing, and if there be a gentle circulation
of such air within the cave, then ice may be formed.
Again, the entrance to the Flagstaff cave is a t the bottom
of a general depression in the ground ; it must, therefore, re-
ceive the very cold air that settles into such hollows during
clear nights; this air is cooled by contact with the surface of
the ground, which latter is cooled hy radiation to the clear
sky. Even during the warm siininier months the nocturnal
radiation at this altitude (about 7,000 feet) is sufficient to
produce temperatures below freezing, so that the water perco-
lating through the soil into the cave may be frozen by con-
tact with the cold air within the cave if the latter is slowly
renewed every night.
The formation of ice in the cave near Flagstaft' is un-
doubtedly not an isolated case aud similar examples should
be sought for and brought to ths attention of the readers of
the MONTHLY WEATHER REVIEW. Those interested in the
subject would do well to test our suggested explanation by
making accurate observations of the tsmperature and moisture
of the air close to the surface of the ground at the time of ths
morning minimum temperatures, and especially during the
summer months.
The Ice Trade Journal has 'from time to time published
accounts of similar ice caves in various parts of the world.
The February number states that about twelve miles from
Ehreiibreitstein and a short distance from the Wallmerod