102 MONTHLP WEATHER m m . APRIL, 1908
alarm system because we want frequent tornadoes, but quite on the con- trary because we do not, but want to be forewarned when there is one. The Weather Bureau omciala deserve credit for the work that they
have done in giving us facts and figures to work from, as well as the many wonderful discoveries they have made. They have taken an
uneducated people which had all kinds of superstitious ideas in regard
to foretelling the pending weather, based on myths and old traditions, until after a process of evolution and hard work on their part we have
now a Weather Bureau superior t o any in the world. They educated
themselves while educating the masses until they have reached this
state of proficiency. All this has-been accomplished within the last forty years, and if these same persons are kept in charge of this work,
I believe our Bureau will advance as much within the same time in the
future. While there is life there is room for progress.
I have read your articles in the WEIITHER REVIEW and have gained much information in regard t o lows and highs and the conditions accom- panying them, and it seems t o me that there is not much work left
undone. I also read what you write with special interest, because it impresses me that you are dealing with facts as you flnd them regardless of what theory they may upset or uphold; like all true scientists, you are seeking the truth. I am only a beginner, and any suggestions and information that you
will kindly give will be appreciated. I am open to conviction and believe that we all should so school ourselves aa to be a61e at the end of each
period to slough off the skin of preference or prejudice that may have hardened itself around us during the last period.
(4) REPLY SENT TO SECOND LETTER BY EDITOR.
I n reply to yours of July 27 I may thank you for saying that the Weather Bureau deserves credit for the work it has done in giving facts and flgures, and educating the people above superstitions and errors In regard to the weather; but our efforts t o benefit the people will be in vain
if, in spite of our facts and figures, you create an unnecessery dread or fright with regard to tornadoes in your locality. I see no reason to be-
lieve that your system of telegraph line and automatic signals will give any reliable forewarning of a tornado: and should advise you and the city not to waste money on it. You state your belief that only a small
per cent of tornadoes do damage at the earth's surface, in your State, and the rest do not reach the ground. You also add that you can not give any additional information about tornadoes, because the public gen- erally call them cyclones. Neither of these ideas is true; the use of two
terms, tornado " and 'L cyclone," need not produce any confusion in the statistics of frequency. The tornadoes that do damage et the earth's surface are the only ones that need to be counted in any efforts that you
make to provide against them; and, as I wrote before, them are so rare that a region four miles square need not expect to have more than one
in ten thousand years. If you count every destructive wind and every
imaginary tornado far above the ground in the dark and threatening clouds as a proper reaaon for fright and anxiety, you will produce a wholly
unnecessary state of uneasiness and alarm in the community.
You say there is no expense you would not undergo to protect your' life, but you do not protect it efficiently by your telegraph line and fore- warnings of tornadoes. The chance of your dying from a tornado is not the ten-thousandth part of your chance of dying from disease, accident, lightning, etc., and it would be a wiser policy t o spend your money to protect yourself against these. The mere forewarning of a tornado is no protection against its coming.
THE OBSERVATORY ON MOUNT ETNA.
Under date of May 16, 1907, at Messina, Sicily, Prof. G. B.
Rizzo, the director of the observatory recently built near the
summit of Mount Etna, wrote that he was about to start for
the summit and to occupy the observatory there for the sum-
mer, where he would make a series of observations on the
intensity of solar radiation, as measured by means of the Ang-
str6m pyrheliometer. This instrument is a duplicate of that
which has been used for the past five years by Mr. H. H. Kim-
ball, and on account of the special interest taken in this sub-
ject by American students Professor Rizzo proposes to com-
municate his results for publication in the MONTHLY WEATHER
REVIEW.
The importance of continuous meteorological work on
mountain summits is felt more and more as our knowledge of
meteorology progresses. The balloon work and kite work
must be supplemented by regular mountain stations; these
latter are practicable and inexpensive where balloon work
would be impracticable. There are many noble peaks on
ocean islands that still remain to be occupied, and even if they
o m not be oocupied immediately, yet the cloud phenomena
about their summits should be systematically observed.
The following description of the ascent of Mount Etna is
abbreviated from an account by Maj. Albert Woodcock, for-
merly United States Consul at Catania, Sicily, whose letter
was published in the Sportsman Tourist, Vol. LXI, New Pork,
July 25, 1903, which contains much interesting information,
but we have omitted that which is not appropriate to the
MONTHLY WEATHER REVIEW.
two stout horses left Catania to make the ascent of Mount Etna and
the descent into Val del Bove. A hammock beneath the carriage and a boot at the rear contained blankets, rugs, overcoats, and rations Por a
two days' campaign. We were soon looking down upon Catania with its thousands of lights, and upon the beautiful sea.
The moon was at i t s full. As we lscended t h e air grew fresher and more bracing; i t had been unm,mfortabiy warm in Catania when we left.
We were ascending thru a highly cultivated region. Orchards of orange, lemon, almond, and flg and vineyards of grape grow luxuriantly upon
the slopes. I n an hour and a half we had ascended to Gravina, an un-
important village of low, lavve-constructed houses. Two miles higher up
we reached the quaint old town of Mascalucia. Perched high up on the side of Mount Etna, it commands flne views of the sea and landscepe
below. There twilight commenced to steal upon us, and the morning
star that had glowed with unusual brilliancy above the Calabrian peaks
began to pale. Still higher up we reached the lava village of Torredi
Grifo. We were now above the orange belt. I n this high altitude in winter are heavy frosts and frequent snows. We now entered upon a barren waste of lava bed, which marks the eruption of 1637.
We arrived at Nicolosi. 2,265 feet above the sea, at 6 o'clock, a. m. Nlcolosi is an earthquake-rlven town, and has several times been shaken
to the ground. The lava, flood of May last approached within 1,ooO feet of it. It there stands a black, hideous mass, still hot and sending off sulphurous vapors. We rested at Nicolosi for an hour, refreshing
ourselves with cold coffee, bread, and cheese. Signor Orazlo Slivestri, professor of chemistry, geology, and miner- alogy of the Royal University of Catania, courteously tendered us the
use of the observatory. The dlrect road of ascent is covered by the lava flood of May last from 20 to a 100 feet deep. We were obliged to make
a detour around this hideous fleld of black desolation. We flanked Monti
Ross1 (the Red Mountains) on the south.
Soon after leaving the Red Mountains, we came to a spur of the lava bed of May last. It was insufferably hot. Our niules quickened their
pace in crossing. We had left the cultivated region at Nicolosi and were
now entering the wooded belt. The treeskere mostly of a young growth
of chestnuts. Wood being in great demand, the trees were cut before they reach the ordinary size. I n thls same wooded region, however, on the west side of Mouiit Etna, there are several monarchs of the forest
that have escaped the woodman's ax. They are said to be the oldest trees living and are without doubt 1,OOO years old.
Our ascent was very slow and tiresome to the mules. The last May eruption had covered the ground with volcanic sand. The trees seemed to rise from a black sandy desert, there being no green thing visible but
thelr ramage. We reached Casa del Bosco (House of the Woods) at 10
o'clock a. m., tired and voraciously hungry. We were now at an altitude
of 4,216 feet above the sea. Casa del Bosm is the last resting place be-
fore the final climb to the summit.
We wound around the east side of Mount Castello and ascended between Monti Agnuolo and
Frumento. We were above the habitable zone. All appearances of vege- tation had ceased. No bird fluttered by us, no cricket chirped. There were no signs of animal or insect life. All about u s was black desola-
tion. Sun-lit clouds were hanglng upon the crests below us. Our way waa over black volcanic sand and loose boulders of lava. We were soon upon Piano del Lago (the plains of the lake). Lava floods have filled it, and it has ceased to be a lake. Case Inglese is 9,652 feet above the sea. It is situated at the base of
the great cone. It was erected in 1811 by some omcers of the British
Army; the Engllsh at that time occupied Sicily. It is a low one-story building, constructed of lava rock, and stands east and west; in one of the three rooms isa flreplace. This building is the refuge of excursionists
to Etna. The observatory now (1886) is a low two-story building sur-
mounted by a dome. It is built of lava rocks, the walls being of unusual
thickness, to withstand the frequent shocks of earthquake. It is joined
to Casa Inglese, the latter being a lean-to on the south to the former.
A telescope and all other instruments requisite for making observations
in astronomy, meteorology, etc., have been purchased and will soon be mounted in the building. Owing t o the kindness of Professor Silvestri
(as before stated) we were in possession of the observatory. Here we found beds, bedding, table, chairs, etc., designed for the use of the
scientists: these, for the time being, were ours, and we were supremely comfortable. After an hour's rest our company mustered for the ascent
of the great cone. It towered into the heavens 1,900 feet above us, its sides being very steep. We finally reached the north rim of the crater. The grand old sea and
the Calabrian peaks lay outstretched before us. Sun-lit clouds in great
At 3 o'clock a. m. of August 14 last (1886), a large carriage drawn by.
The ascent became steeper and more difficult.
~B I L , 1908. MON!CHIJY WEA!L'HER REVIEW. 103
billows were floating below us. These, tho wonderfully beautiful, dyed
in t h e rich colore of the declining sun, shut off the greater portion of the
island from our view. On my previous visit to Etna, in May, 1884, the atmosphere was much clearer. Then we could see the greater part of the
island. The entire east coast was outstretched below us. The billows
of the sea breaking upon the rocky mast gave it a silvery edging. Two cities and a vast number of villages and hamlets incrusted the seashore, dotted the valleys. and nestled on the hillside. The Sicilian Mountain
chains rose about us in great irregular ridges, crest peeping over crest.
Stromboli to the north (seemingly but a stone's throw away), protruded his rocky head and shoulders above t h e sea. He was throwing a dense column of black smoke thousands of feet into the heavens. Adjacent was the little island volcano throwing upward white puffs of clouds. Mount Etna at the same time was shooting upward an immense column
of sulphurous steam, rendering it impossible to see much of the interior
of the crater. An inky black cloud hung below us at the.west. From
it came zig-zag.chains of lightning flashes and thunder peals. We looked down upon the storm; it waa raining below us, but we were in the sun-
shine above. When the heavens are free of clouds the whole island, with ita innu- merable mountain peaks, is visible from the rim of the crater. With a glass the waves of the sea may be seen breaking in foam upon the rocky
coast of t h e entire island. Malta is vislble in the south, Stromboli and
the Lipari Islands to the .north. the Aegedian Islands to the west, and the three great seas of the Mediterranean-the Ionian, the African, and
t h e Tyrrhian.
The sun was low down in .the west and seemed to swim in a sea of
glory. A stratus of clouds lay low in the heavens shutting off all view from the west. The stratus did not resemble clouds, but looked like a vast sea flecked with gold by the setting sun. As the sun neared the western horizon, it cast a great purple shadow of Etna against the east- ern sky. It was triangular shaped and seemed to hang vertically in the heavens. For a time the rising moon shone with ita silver light in the
very apex of the purple pyramid. It waa the strangest and most 'beauti-
ful scene my eyes ever beheld.
DUSTF'ALL IN IDAHO.
Under date of April 18, 1908, Mr. F. Roch, the special ob-
server of Wallace, Idaho, writes:
Twice within the past ten days we have had rainfalls so heavily
charged with dust-the dust in dry form falling in flakes the size of a pin- head-that they might-be called dustfalls instead of rain. These specks
of dust came down aa straight a s it would be possible for a gentle rain
to fall, and the fall continued for several hours intermittently.
This large quantity of dust must have had a special origin
nearby and we hope that Mr. Roch will trace it to its source.-
EDITOR. -
METEOROLOGICAL EDUUATION.
In connection with the statistics of educational work by
Weather Bureau otiicials, the editor would be glad to know
of stations at which such work could be done more satisfac-
torily than now if some one especially fitted as teacher were
attached to the local ofice force. Of course the teaching is
only a small part of the official work, but it is well to have it
done creditably to the Bureau. The subject is really so im-
portant and so interesting that we think colleges and acade-
mies will certainly take pride in being pioneers in the work.-
EDITOB.
THE LAW OF THE EARTHS NOUTURNAL UOOLINO.
In 1873 A. Weilenmann' showed that' the normal tempera-
ture curve from sunset to sunrise may be represented by a for-
mula appropriate to the Newtonian rate of cooling, that is by
e=@o+ Cbt .................... (1)
where t denotes the time measured in hours from midnight, 8
the temperatures at time t, and eo, Cy b are constants chosen
to fit the observations as well as possible. Further, he found
the striking agreement between the values of b for different
places, as shown in the following table:
By Prof. WILLIAM 11. JACKSON. Dated Haverford College, Hmerford, Pa., May 1% 1908.
1 Ueber den Wiglichen Gan~ der Temperatur in Bern. Schweizerische Meteorologische Beobachtungen. Band IX. 1872.
TABLE l.-Vduea of b for difermt placea.
Place.
Hobarton.. ........................................... Berne. ............................................... Great St Bernard.. ...................................
Jt. Peteraburg. i . .................................... Ghent.. ............................................... Prague ............................................... Toronto ............................................... Batmis.. ............................................
Duration of observatiom, in years.
8
I
19
18
?A
1s
6
S
In 1888 M. Alfred Angot' found that the corresponding
values of log b for St. Maur, near Paris, were x940 for clear
nights and E936 for cloudy nights. This is an independent
confirmation of Weilenmann's results, and seems to show what
might perhaps be inferred from those previous results, that
the value of b is practically independent of the state of the
atmosphere.
I was informed of these facts early in 1906, when Prof.
Arthur Schuster drew my attention to a paper by Dr. 5. Tetsu
Tamura: which gives an excellent account of the whole subject.
At the same time he suggested that the facts could probably
be explained by supposing that the earth radiated like a black
body and that the question might be treated as one of heat
conduction.
Attempts to treat the matter theoretically only led to two
negative conclusions. First: It is unlikely that such a law
can represent the actual facts, because such a law implies a
solution of the differential equations to be solved of the form
where 2 denotes the distance from the surface of the earth.
Such a law as this implies that all temperatures are decreasing
at the same rate; whereas we know that the relative tempera-
tures of the earth and atmosphere vary considerably in the
course of the night. Secondly: I f such a law represented the
state of affairs, the coeficient b would vary from place to place,
according to the nature of the ground.
Or we may look at the question from a purely theoretioal
point of view. Following Riemann,' the solution of the prob-
lem of the cooling of a very large conducting sphere, origi-
nally everywhere at unit temperature, and radiating heat
into space at a rate proportional to the constant h, allows the
surface temperature to be exprest by the formula,
e =f (z ) e-w,
m
(2) e = 2n- 4 he&h?t/ ds ..............
u v r
where a is the diffusivity of the sphere. Extending this
formula to the case of a sphere normally in a steady state of
heat flow, but which has been subjected to a uniform increme
of temperature, and which is then left to return to its original
normal condition, we obtain the series,
e = e,+ O'(1 - 3~~aZ,t*+ a'h'l+ $r4dh"ta +. .... .). .(3)
To obtain a more approximate solution for the actual case
of the earth, we should of course suppose that the disturb-
ance from the normal state was not a uniform increase of tem-
perature, but a complicated function, decreasing as the dis-
tance below the surface of the earth increases. I have not
thought it worth while to attempt this, because as explained,
later, I believe the problem is best attacked by other methods.
1 Influence de la NBbulosit6 sur la variation diurne de la temperature B Paris. Annales du Bureau Central. 1888.
a Mathematical Theory of Nocturnal Cooling of Atmosphere. Monthly Weather Review, April, 1905.
4 Partielle Differentialgleichungen und deren Anwendung auf physi- kalische Fragen. Par. 69, 3d Edit. 1882. The same result is obtained
by a different method by Camlaw, Fourier's Series and Integrals. 1906.
P. 246.