The Washington herald., 1913-11-09

as new discoveries were made In elec-
tricity and aeronautics. brigadier
general has charge Of all matters per.
tanning to signalling. He is expected to
find out what other countries arc doins
and to keep abreast Of the times al
home
Though they had made a good many
flights in Ohio and Florida with their
areoplane, the Wright brothers were
practically unknown to the world until
in 1905 they tested their machine a.
Fcrt Myer in the presence of the prin-
cipal signal officers of the army. Fort
Myer, a military post, is on the south
hank Of the Potomac, in sight OF WASH
tngton, and was named in honor OF the
young surgeon, who, II is reasonable TO
| say, learned the rudiments OF signalling
from the Indians on the plains and in
the mountains of Texas and New Mex
leo.
Signals Once Carried on Trains.
The new chief of the Weather Bureau
began his service with the national gov
| ernment in 1854 He was ffty-five years
| old on the 7th OF October, but he looked
4 much younger Columbus, in Ohio, had
been his home. While a student at the
State University, where he specialized in
physics and mechanical engineering, he
| came under the influence of Thomas c.
| d very ltdTueu anu
| able man. The association turned
Charles +. Marvin into a meteorologist-
7 DR.. Mendenhall had been professor of
| physics at the Imperial University of
| Japan and had founded a meteorological
| observatory in Tokyo. He organized a
| State weather service in Ohio and de-
I vised system of signals for display on
! railway trains SO that persons living
| along the tracks might know IL they
were TO have sunshine or rain. The
| scheme was generally adopted in the
United States and Canada
| Newspapers were not so widely cir
culated as they are now, and the signal
4 flags on passenger trains was an ex-
/ cellent method for spreading information
about the weather. Farmers watched
for the early morning trains which passed
| their doors, and hackmen at village
depots circulated meteorological news
among merchants and the rest Of the in
habitants.
II had just been graduated from the
University" DR.. Marvin told me, land
was looking around for employment in
my line. Prof Mendenhan happened to
know that the civilian corps of the sig
nal service needed an assistant professor
of meteorology. Lpassed the required ex-
! animation and obtained the place. On
coming to Washington, was detailed to
make some investigations and prepare
several
The tables are still in use. Humidity,
accurately defined, means the amount
of aqueous (or watery) vapor in the
atmosphere compared with that which is
required to saturate it under the given
condition as to temperature When the
atmosphere is completely saturated the
humidity is expressed at 100; If the atmo-
sphere is entirely dry, there Is no hu-
midity, of course, and that state Is ex-
M hv n
He Tackled Big Subject.
Humidity is caused by oceans, lakes,
and rivers and growing vegetation.
Trees and all kinds of plants draw great
quantities of water out of the earth.
How they draw it and then push IL up
to the topmost leaf on the highest branch
is a disputed matter. The mechanics
Of the process have been set forth in
many long and contradictory papers.
But the moisture goes up and a GER
tain part of 1t, or possibly all of 1t, Is
thrown on into the atmosphere. Trees |
and plants, in short, sweat like human |
beings. So young Marvin, fresh from
the university, was ordered to tackle a |
large and complicated subject But he |
soon got in among the instruments. He |
is said to be very great inventor.
oh, he modestly replied, when /
mentioned his reputation, almost any
thing Of value in mechanics is the work |
of men following one another. The rail- 1
road locomotive is a visible illustration |
of the growth Of a primitive machine |
from generation to generation toward |
final perfection"
ITO whom" asked DR.. Marvin. 'tare |
your weather forecasts OF the most |
service?''
I'VE like to believe" he answered, |
that the forecasts are of value, or of |
interest, at any rate, to everybody. They /
are made twice each day, at O'Clock /
in the morning and at o'clock in the i
evening. There are forecast stations In /
Washington, New Orleans, Chicago, Dem
yer, and San Francisco.
From these stations go the forecasts
which cover the whole country. WASH
ington, for instance, tells what the
weather is likely to be in the eastern
part Of the country. New Orleans makes
forecasts for the South and Southwest.
The forecasts are based, of course. OF
the reports Of many observers in each
district
"A picture of the conditions grows up
in the mind Of the forecaster. He
knows, from his knowledge and expert
ence, what Is likely to happen. Sud-
den local changes In the atmosphere
may occur, however. and his forecast
then becomes inaccurate. Sdll the er-
rors only number fifteen in each one
hundred OF his attempts to foreteIl the
weather.
''Then there are forecasts about frost