Chapter IV: Investigating the Upper Air

_Balloon Soundings into the Stratosphere._--It was the writer’s privilege to be present when some highly interesting and instructive experiments made by the Weather Bureau in coöperation with the Smithsonian Institution, in sounding the upper air were made at Avalon, Santa Catalina Island, off the coast of southern California in July and August, 1913.[J] The results of this work were in close agreement with similar soundings of the upper air throughout other surveyed portions of the earth’s atmosphere, and a record ascension for this country was made on July 30--32,643 meters or 20½ miles. In common with other observations of temperatures in the stratosphere, the minimum temperature of these soundings (-90 F., August 3) was registered within the first 10 miles.[K]

[J] University of California Chronicle, 1915, 17:1–25, Berkeley.

[K] Monthly Weather Review, 1914, 42:410, Washington.

Of especial interest to the aviator is the table on the next page which shows wind velocities increasing with elevation as determined by observations of the Avalon balloons.

RECORD OF AVALON ASCENTS, JULY-AUGUST, 1913

_Table showing Theodolite observations of wind velocities (meters per second) at elevations of 1,000 and 5,000 meters_

======+=======+=======+=======+=======+=======+======+======+======+====
|Meters |Meters |Meters |Meters |Meters |Meters|Meters|Meters|
| per | per | per | per | per | per | per | per |
Meters|second |second |second |second |second |second|second|second|Mean
|5 p.m. |5 p.m. |10 a.m.|10 a.m.|10 a.m.|5 p.m.|4 p.m.|5 p.m.|
|July 24|July 27|July 31|Aug. 1 |Aug. 2 |Aug. 3|Aug. 7|Aug. 8|
------+-------+-------+-------+-------+-------+------+------+------+----
1,000 | 2.5 | 1.0 | 5.6 | 6.6 | 2.3 | 5.8 | 7.1 | 1.9 | 4.1
1,500 | 6.2 | 0.8 | 6.2 | 8.1 | 3.3 | 5.0 | 6.4 | 1.5 | 4.7
2,000 | 8.0 | 1.2 | 5.8 | 7.0 | 4.1 | 4.5 | 6.5 | 6.0 | 5.4
2,500 | 10.0 | 1.8 | 10.8 | 5.7 | 5.2 | 4.2 | 4.7 | 3.6 | 5.8
3,000 | 12.0 | 2.3 | 9.4 | 6.1 | 7.2 | 5.2 | 3.5 | 4.1 | 6.2
3,500 | 12.8 | 2.5 | 8.0 | 6.7 | 7.4 | 6.1 | 4.6 | 4.6 | 6.6
4,000 | 13.6 | 3.8 | 11.2 | 7.4 | 9.2 | 5.2 | 6.4 | 3.2 | 7.5
4,500 | 14.3 | 5.2 | 14.6 | 8.5 | 11.2 | 1.8 | 7.8 | 3.0 | 8.3
5,000 | 21.2 | 6.2 | 12.8 | 10.3 | 10.4 | 2.3 | | 3.4 | 9.5
------+-------+-------+-------+-------+-------+------+------+------+----

_Charts Showing Upper-air Weather Conditions._--It is believed that the following charts when examined in connection with the accompanying explanation in the text will give the reader something of an outline as to the conditions existing in the upper regions of the atmosphere.

_Horizontal Projections of the Paths of the Sounding Balloons Liberated at Avalon, California, July 23 to August 10, 1913_

Reproduced from the _Monthly Weather Review_, 42: 423

This figure shows the horizontal projections as far as the
balloon was observed, not the entire distance traveled until it
landed.]

_Vertical Temperature Gradient, Avalon, California, July 27, 1913_

Solid line represents the ascent of the recording apparatus,
the dotted line the descent. (Verticals 25° C. or 45° F.)

Reproduced from the _Monthly Weather Review_, 42: 412]

_Mean Vertical Temperature Gradient_

Figure reproduced from _Monthly Weather Review_, 42: 413.

Altitude values are in kilometers at the left, and in miles at
the right: Temperature values are in Centigrade at bottom, in
Fahrenheit at top.

Maximum airplane altitude 26,242 feet or 5 miles.]

_Diagram Showing Increase of Wind with Elevation Data from Eight Meteorographs_

From the article “Free Air Data in Southern California,
July and August, 1913” by Dr. Wm. R. Blair, Professor of
Meteorology, in the _Monthly Weather Review_, for July, 1914,
it is learned that the wind shifts from west to east rather
abruptly at 16 to 20 km. (10 to 12 miles); below this level
down to about 5 km. (3 miles) it is quite uniformly from the
west. Extremes: Maximum wind velocity 21.2 miles, 5,000 meters
elevation, 5 P.M., July 24; minimum wind velocity 0.8 miles,
1,500 meters elevation, 5 P.M., July 27.

The table shows a steady increase in velocity of the wind
with elevation, the data being obtained from the eight
meteorographs. There were four morning flights (July 31, August
3, 7, 8) and five afternoon flights (July 24, 27, August 3, 7,
8, 1913), and elevations were computed for nine heights, 1,000
to 5,000 meters. Beyond the 5,000 meters the records show that
from 2 to 7 miles altitude the wind increases at approximately
the same rate that the density of the air decreases.]

_Chart Showing Number of Flights and Duration in Hours for the Months of July to December, 1915, and January to August, 1916_

Prepared by the War Department, Signal Corps Aviation School,
San Diego, California, and furnished through the courtesy of
Col. W. A. Glassford, Signal Corps, U. S. Army, Commanding
Officer, September 14, 1916.]

(_Designed by Morgan_)

This medal was awarded Orville and Wilbur Wright by resolution
of Congress, March 4, 1909. Bronze replica in possession of the
writer.

_Photographed May 31, 1916, by permission of the Director of the Mint, Philadelphia_]

_Photographed July 27, 1913_

This set was liberated from the base of the U. S. Weather
Bureau, Avalon, Catalina Island, California, at 4.57 P.M., July
27, 1913, and rose to a height of 23,870 meters in one hour and
three quarters when one of the balloons burst and the descent
began. This was observed by Carpenter at the theodolite.]

_Photographed August, 1913_

This meteorograph rose to a height of 23,870 meters (94,716
feet), at which height the pressure was 23 mm. (0.906 inches),
temperature -52.1 C (-58 F.), relative humidity 21 per cent,
wind E. (or more precisely S. 79 degrees E.), velocity 6.1
m.p.s. (14 miles per hour), but the minimum temperature was
registered at 15,228 meters (49,960 feet) when the thermometer
showed -64.7 C. (-85 F.), at which time the pressure was 89 mm.
(3.504 inches of the barometer), relative humidity 19 per cent,
wind N.W., 3.4 m.p.s. (8 miles per hour).

The basket was picked up at sea off Oceanside, San Diego
County, about 90 km. (145 miles) east of Avalon.

For the first 6 miles of ascension the balloon moved upward at
the rate of 8 miles per hour.]

_Photographed September 10, 1908_

This photograph was made at Fort Meyer, Virginia, of the
original Wright biplane, piloted by Mr. Orville Wright With
Colonel G. O. Squier, U. S. A., as first passenger.

When this photograph was made no fatalities in airplane
flight had occurred; the first victim, Lieutenant Selfridge,
U. S. A., was killed while riding with Mr. Wright in the same
biplane shown above, on the Tuesday following the Saturday this
photograph was made, the machine falling to the ground at a
spot which is practically the center of the picture, but near
the trees which are part of Arlington National Cemetery.]

_Photographed December 24, 1915_

A special meteorological station of the Weather Bureau was
established on Mount Wilson, December 25, 1915, and on April
1, 1916, daily reports of temperature, weather, precipitation,
relative humidity, fog and other conditions were first
telegraphed to the local office of the Weather Bureau at Los
Angeles for publication and distribution.

The photograph shows the location of the meteorological
observatory(*) and the valleys below. From the elevation of
the observatory (6,000 feet above sea-level), it is possible
for the observer to determine the thickness and extent of fog
as it is feasible to see as far southwesterly as Point Loma
on a clear day, and southerly to Santa Catalina Island. Such
observations and reports have been made and forwarded without
interruption to date. They have proven of incalculable value to
the aviators making cross-country flights.

The station on Mount Wilson is maintained through the
coöperation of the Carnegie Institute of Washington.]

_Photographed October, 1911_

This photograph of Mr. Glenn Curtiss in his “pusher” airplane
was made shortly after the Curtiss School of Flying was
established in 1911, on North Island. At his right is Local
Forecaster Carpenter.

Comparison of this machine, which four years ago was the last
word in airplanes, with the tractor shown on the opposite page,
indicates the rapid progress in design.]

_Photographed October 18, 1915_

Aviation Instructor Oscar Brindley discussing a flight with
Captain Clarke, U. S. A., and other officers at the U. S.
Aviation School at San Diego.

Mr. Brindley is standing by the side of Captain Clarke in the
group at the right. After every flight the Instructor reviews,
point by point, the features of the flight, showing the pupil
his deficiencies and explaining how he may avoid them in the
future.

The officer at the left, Lieutenant Brown, has the regulation
leather leggings, coat and helmet, and is ready to go up as
soon as the mechanicians (who may be seen at the extreme left)
finish inspection and pronounce the airplane fit for the next
flight.]

_Photographed October 21, 1915_

Captain C. C. Culver, U. S. Cavalry, Adjutant, Aviation School,
with a parachute in his hand, having word with Captain L. W.
Patterson, U. S. A., before the latter’s flight. The object
of the parachute is to determine changing wind-direction at
different heights.

The airplane wireless record is now held by Captain Culver. In
October, 1916, he sent a message 119 miles from Santa Monica
to San Diego, California, while flying at an altitude of 1½
miles. He received a radio message from a distance of 11 miles
while flying 7,000 feet aloft. He is also the first military
aviator to rig up two airplanes so that they could exchange
messages while in flight. The radio set used weighed less than
forty-five pounds.]

_Photographed October, 1915_

The noise of the motor, together with the terrific blast of
air, makes conversation impossible between the pilot and
observer; for that reason telephones are sometimes installed as
noted in this photograph.

Lieut. Edgar S. Gorrell is shown as the observer in this
photograph. He has since qualified as an aviator and made a
brilliant record in the Mexican activities in 1916.]

_Photographed October, 1915_

The peninsula of Point Loma rises to an elevation approximating
500 feet, and as it lies approximately north and south, it
interposes a considerable barrier to the prevailing westerly
winds. The eastern side of Point Loma is very precipitous.
These factors tend to produce winds called “woollies” which are
a distinct menace to all small boats and air-craft, unless the
air-craft have an elevation exceeding 3,000 feet on a normal
windy day.]

_Photographed October, 1915_

Contrasted with the photograph of Point Loma on the opposite
page, this picture shows the ideal water conditions for trying
out seaplanes. Shortly before this picture was taken, one of
the pilots of the Curtiss Aviation School, also on North Island
drove a big seaplane 100 miles per hour barely skimming the
surface of the water.]

_Photographed October 20, 1915_

Instructor Oscar Brindley and the observer, Meteorologist Ford
A. Carpenter, U. S. Weather Bureau, leaving the ground for a
flight. In the military tractor used generally by the Army,
the observer sits forward while the pilot occupies the after
cockpit. This machine, like all others used in the military
service, has dual control.]

_Photographed October, 1915_

Motor, horsepower, 80: revolutions per minute, 1,277.
Diameter of propeller, 8 feet.
Load of 39 gallons gasoline, 2½ gallons oil.
Flying radius with normal equipment, two persons, 300 miles.
Maximum altitude obtained with this model at San Diego, 13,000 feet.
Wing-spread, tip to tip, upper, 38 feet, 10 inches; lower, 34 feet,
10 inches.
Supporting area, upper, 139 square feet; lower, 165 square feet;
total, 364 square feet.
Length of fuselage from rear of propeller hub, 21 feet, 6¾ inches.
Data from Major F. P. Lahm, Signal Corps, U. S. A.
Dated May 9, 1916.]

_Photographed October, 1915_

Military Tractor No. 50 just before leaving the ground. In
gusty weather the mechanicians steady the ends of the lower
planes, sometimes turning it by holding one edge and pushing
the other. In the photograph the mechanicians are giving the
airplane steerageway to the right.]

_Photographed October, 1915_

Before attempting to leave the ground there is always
considerable jockeying for a favorable head-wind, and the
photograph shows Instructor Brindley maneuvering for a
favorable pointing.

After leaving the ground, the wind, so long as it is not gusty,
makes no difference to the pilot.]

_Photographed October, 1915_

The new municipal wharves are in the middle foreground and to
their right may be seen the Santa Fé station. Part of North
Island is obscured by cloud.]

_Photographed October, 1915_

This photograph was made 1,000 feet above the clouds. The
wharves of San Diego and Coronado may be seen in the foreground
and in the middle distance.]

_Photographed October 20, 1915_

The airplane, in which the pilot, Oscar Brindley and the
observer, Meteorologist Carpenter, made their flight, was
photographed at the maximum elevation, 3,500 feet above the
aviation field.]

_Photographed October 5, 1915_

The regular observation tower from which all observations and
notes on every flight are made is just back of the headquarters
building. The station anemometer is on the tower, and the
portable anemometer is to the left.]

_Photographed October, 1915_

During the flying periods, the motor-boat of the U. S. Aviation
School is kept ready for instant service in order to work in
conjunction, if needs be, with the Medical Corps emergency
truck on land.

Such is the speed of this boat (exceeding 40 miles per hour)
that the water no longer has resiliency, and it is about as
comfortable as riding in an old-fashioned stone-boat over rocky
pastures.]

_Photographed October, 1915_

Part of Coronado and the portion of land called North Island,
separated by Spanish Bight. Point Loma may be seen at the
extreme upper right-hand corner of the photograph. The
flying-machine sheds, buildings of the Aviation School, etc.,
may be seen in the immediate foreground. The U. S. Cavalry camp
is the white splotch in the center foreground.]

_Photographed October, 1915_

In the repair shop of the U. S. Aviation School at North Island
the motors are given a gruelling test, being run twenty-four
consecutive hours at a speed greater than that given them in
actual practice. After this run they are taken down and each
part is spread out on a large drawing-table and is subjected to
close scrutiny so as to show any defect. Several airplanes as
well as seaplanes have been reconstructed in this shop.]

* * * * * *

Transcriber’s note:

Punctuation and spelling were made consistent when a predominant preference was found in this book; otherwise they were not changed.

Simple typographical errors were corrected.

Ambiguous hyphens at the ends of lines were retained; occurrences of inconsistent hyphenation have not been changed.