Glasgow, as long ago as 1749, resuscitated kites
from their long burial with a similar idea of em-
ploying them to measure temperature.
In the author's experiments, steel wire was
first employed to fly them with. Two kites of
diamond pattern made of tussore silk and bam-
174 THE STORY OF THE EARTH'S ATMOSPHERE.
boo frames were flown tandem, and four self-
recording Biram anemometers weighing i IDS.
each were attached at various points up the wire.
Heights from 200 to 1500 feet were reached by
the instruments, and the.increase of the average
motion of the atmosphere was measured on sev-
eral occasions for three years. Kites were also
employed, first by the author in 1887, to photo-
graph objects below by means of a camera at-
tached to the kite wire, the shutter being released
by explosion. Since that time kite photography
has leapt into popularity, and has been success-
fully practised by M. Batut in France, Capt. Ba-
den Powell in England, and Eddy in New Jersey.
The figure following represents a recent pho-
tograph of Middleton Hall, Tamworth, taken by
Capt. Powell with a kite-suspended camera at a
height of about 400 feet above the ground.
At the Blue Hill Meteorological Observatory,
near Boston, Mass., which is carried on by Mr. A.
L. Rotch, tandems of kites are used to elevate a
box of self-recording instruments, cameras, etc.
The adjoining fig. (41) shows the building,
which is 630 feet above sea level, and a tandem
of Hargrave kites supporting a camera with the
adjustment involving the use of an extra cord for
slipping the shutter, devised by Mr. W. A. Eddy.
The height of the camera is determined by simul-
taneous observations of theodolites at the end of
a base line.
By attaching several kites to the same main
wire great altitudes have been reached at Blue
Hill, and complete records of the pressure and
temperature recorded on a revolving drum of a
Richard's thermograph and barograph.
The highest point attained so far was 9385
SUSPENSION AND FLIGHT IN ATMOSPHERE. 175
feet above sea level, in October, 1896. In order
to accomplish this, nine kites (of moderate size)
and three miles of steel wire were required. At
the highest point the temperature fell to 20,
while at the observatory, 8755 feet below, it
On other occasions when the author was
present heights of 6079 and 7333 feet were at-
For all such purposes, therefore, kites are able
to do as much as free balloons up to about three
miles. They are also cheaper and more portable
176 THE STORY OF THE EARTH'S ATMOSPHERE.
than captive balloons, and possess far greater ele-
vating power, especially in windy, weather, when
such balloons are nearly useless.
FIG. 4 i.
It was further suggested by the author in
1888,* that kites could be used for various pur-
poses in war as well as science.
* Les Cerf Volants Militaires. Bibliotheque des Con-
naissances Militaires. Paris, 1888.
SUSPENSION AND FLIGHT IN ATMOSPHERE. 177
Since then Capt. Baden Powell, in May, 1895,
read a paper on " Kites, their uses in War." In
both these publications it was pointed out that
kites possessed several distinct advantages over
balloons; next, that they could be applied to all
the purposes for which balloons could be em-
ployed, such as signalling, photography, torpedo
projection, carrying despatches between vessels,
and lastly, they could be employed to raise a man
for purposes of reconnaissance.
This question of "man raising" was long
scouted as impossible, but both Capt. Powell and
Mr. Hargrave have practically proved its possi-
bility by elevating themselves by kites, the former
having reached a height of 100 feet.
To give an idea of the size of kite required
for such a purpose, Capt. Powell was lifted by a
single large kite spreading 500 square feet, weigh-
ing 60 Ibs., and capable of folding into a package 12
feet long. Mr. Hargrave, at Stanwell Park, N. S.
Wales, on Nov. 12, 1894, was raised 16 feet by
four kites flown tandem which spread together
an area of 232 square feet, the wind blowing
about 21 miles an hour. The total weight sup-
ported was 208 Ibs. An ounce of fact is said to
be worth a ton of theory. Here we see that in
an ordinary 20 mile an hour wind a kite area
amounting to 250 square feet is ample to support
For a speed of only 10 miles an hour a larger
surface would be required, but if the system of
tandem kites recommended by Hargrave is fol-
lowed, this could be readily attained by the ad-
dition of more kites. Under these circumstances,
by two or more Hargrave kites a man could be
raised, as in fig. 42, and effect a reconnaissance
178 THE STORY OF THE EARTH'S ATMOSPHERE.
of an enemy's fortifications and dispositions,
especially in mountainous country, with consider-
able ease and far greater immunity than in a cap-
The portability of such a series of kites even
for man lifting may be guessed from the remark
by Mr. Hargrave, in a paper dated August 5,
1896, that "a nineteen square feet kite has been
made, that weighs only 19 ounces, and folds
to about the size of an umbrella. Ten of these
could be tucked under one's arm, and with a coil
of line and a decent breeze, an ascent could be
made from the bridge of a torpedo boat or the
top of an omnibus."
The torpedo boat certainly sounds more he-
roic, and probably less dangerous than the om-
Numerous possibilities have been suggested
by Capt. Baden-Powell, and there seems no rea-
son why kites should not enter in as a regular
SUSPENSION AND FLIGHT IN ATMOSPHERE.
part of the paraphernalia of naval and military
Some few years back, the author, with a kite
of the ordinary diamond pattern, 18 feet by 14
feet, was able to carry up 600 feet of steel rope
cable, by which Col. Templer tethered his large
war balloon in Egypt.
This weighed 50 Ibs., and as an additional test,
a man's kit weighing 10 Ibs. was suspended to its
tail. Two such kites could lift a man and pack
away like fishing rods.
Quite recently (July, 1896) a brochure by
Prof. Marvin, dealing with the whole science of
kites, has been published by the U. S. Weather
Bureau. This represents the most complete
discussion of kite-flying up to date, and one or
two of the results are worthy of special record.
The best kites are double plane Hargraves,
with certain improvements in details. Tandems
of two kites only, with 9000 feet of wire out,
have several times reached over 6000 feet in
Kites can be made to fly at angles of 60 or
more, and utilise most of the wind pressure in
By adjusting the point of suspension or alter-
ing the kite, we can make it fly in the ideal po-
sition. This is found to occur when the direction
of string or wire is inclined at an angle of 66 to
the horizon, and cuts the kite plane at right
angles, so that the latter is inclined at 24 to the
Also theory shews that, in order to gain the
greatest effect when kites are flown tandem, the
largest kite or a bunch of two ought to be placed
at the top of the main wire.
180 THE STORY OF THE EARTH'S ATMOSPHERE.
In conclusion. By balloons alone, man will
never be able to complete the conquest of the
air. For travel through the air, or as Prof.
Langley terms it " aero dromics," steam propelled
kites will be the future vehicle. For rest in the
air, it is not impossible that kites will again be a
serious rival of balloons. In fine, we may look
upon kites as likely to take a very much more
important place in the future than in the past
story of our atmosphere.
Before closing this chapter, it is worthy of
notice that the principle of the inclined plane is
made use of in two other important applications
of the motion of the atmosphere besides that of
supporting kites viz., in the sails of ships, and
In the former, the wind meets the sail at a
certain angle, and produces effects analogous to
those on a kite, especially when the latter forges
overhead, under the influence of a freshening
The water here acts like the controlling string,
except that it allows the sail and boat to move
through it, and, so to speak, form fresh attach-
ments every instant. The slip to leeward is
analogous to the lift in the kite, which is checked
by the inextensibility of its string. The back
drift is prevented by the pressure of the water,
and the shape of the main-sail, which tends to
make its forward part, and therefore trn boat,
turn continually towards the wind. The shape
of the boat, the jib-sail, and the action of the
rudder convert this turning-round force into con-
tinuous motion ahead.
As in the case of the kite, there is one posi-
tion (different for each combination of sails and
SUSPENSION AND FLIGHT IN ATMOSPHERE. 181
boat, and varying with the force of the wind) in
which the greatest advantage or speed is attained
for a given direction. To find this and maintain
it is the object of the steersman.
In practice it appears to be very similar to
the best inclination for a kite, so that for any
FIG. 43. Yachting in Sydney Harbour.
wind between head and beam, the sail should not
be inclined more than 24 to the keel. In the
case of a windmill, " the angle of weather," as
it is termed, or the angle which the sails make
with the plane of rotation, answers to the angle
between the keel and the boat-sail, and varies,
according to circumstances, round an average
Windmills are a means of converting the
1 82 THE STORY OF THE EARTH'S ATMOSPHERE.
motion of the wind into mechanical energy, which
may be employed either for pumping up water,
grinding corn, or, as Lord Kelvin suggested in
1881, for generating electricity. Before the
present coal-burning epoch, windmills used to be
extensively employed for corn-grinding. To-day
they are mostly employed in raising water for
drainage, storage, or irrigation. Most railway
stations, every farm-house, and almost every pri-
vate country house in the Middle United States
and Australia, have their windmill and tank.
Labelled " cyclone " or "eclipse," according to
their particular make, they form quite a feature
of the landscape, and it is estimated that there
are more than a million such mills in the United
The "useful efficiency" of windmills, espe-
cially in the modern geared form, is comparable
with that of the best simple steam-engines.
A geared modern wheel, 20 feet in diameter,
will develop 5 horse-power in an 18 mile an hour
breeze, and can be applied to work agricultural
machinery and dynamos for electric lighting.
With a single wheel of this size, Mr. M'Questen
of Marblehead Neck, Mass., U. S. A., works an
installation of 137 electric lights, for which he for-
merly used a steam-engine. As a result, he finds
that he effects a saving of more than 50 per cent.
According to Lord Kelvin, wind still supplies
a large part of the energy used by man. Out of
40,000 of the British shipping, 30,000 are sailing
ships, and as coal gets scarcer, "wind will do
man's work on land, at least in proportion com-
parable to its present doing of work at sea, and
windmills or wind motors will again be in the
LIFE IN THE ATMOSPHERE. 183
LIFE IN THE ATMOSPHERE.
THE limits of space warn us abruptly that we
must bring our story to a close. And yet, facing
us in the book of nature, there is a large unwrit-
ten story of how the atmosphere affects the lives
of men and plants, embracing questions connected
with weather, climate, disease, hygiene, agricul-
The chief elements of climate have already
been dwelt upon in the chaper on temperature
Hygiene and sanitation open out points in
which other factors, such as soil enter as well
The relations of the atmosphere to agricul-
ture, though a subject of immense interest to the
agriculturist, is not a fascinating one to the gen-
eral public. Prof. Hilgard, of the University of
California, has exhaustively discussed this theme
in a bulletin published by the U. S. Weather Bu-
reau, 1892, and Sir J. B. Lawes and Professor
Gilbert have carried out experiments in England,
at Rothampsted, all of which show that in order
to derive our maximum subsistence from the soil,
we must have a thorough knowledge of the ac-
tions which take place between it and our atmos-
The relation of climate to life, health, and
disease is a very wide one, and though it has at-
tracted man's attention for years, it has only re-
cently been studied with anything like scientific
accuracy. An excellent summary of the prin-
1 84 THE STORY OF THE EARTH'S ATMOSPHERE.
cipal modern results will be found in Moore's
As an example of how disease is dependent on
season, the following table will suffice:
Development measured by. Mortality.
Disease Maximum. Minimum.
Enteric fever Oct., Nov. May, June.
Smallpox Jan. to May. Sept., Oct.
Measles June', Dec. Mar., Oct.
Scarlet fever Oct., Nov. Mar. to May.
The opposition between enteric and smallpox,
in regard to season, shows clearly that seasonal
conditions have a great deal to answer for in the
development of disease.
There is little doubt that besides the regular
effects of seasonal changes, the quality of the
air of a place is a potent factor in relation to
We talk of going away for a change of air, and
we know that beneficial effects usually follow if
we choose our fresh locality aright.
The air of cities, as we have seen, contains
vastly more dust particles than that of the coun-
try, and it is full of other impurities, thrown off
by the multitudes of human beings crowded to-
gether in a small space.
The pallor of children in cities compared to
the ruddy health of those who dwell in the com-
paratively unpolluted country air is well known.
Similarly the air on mountains and high plateaux
is less dusty and vastly purer than that near sea-
In certain parts where vegetation decays in
presence of water, noxious exhalations arise
called significantly mal-aria (bad air), and cause
fevers not only in the Mangrove Swamps of the
LIFE IN THE ATMOSPHERE. 185
tropics, but formerly even in the undrained fen-
districts of England.
This bad air usually remains quite close to the
ground, and its effects can often be obviated in
the tropics by sleeping on an upper floor.
The atmosphere undoubtedly acts in many
cases as a disease propagator by conveying
germs from one place to another.
For example the mysterious influenza, which
has of late years so afflicted the whole world, is
evidently propagated through the air. As a rule,
however, water is a far more effective dissemi-
nator of disease than air, and where a good
water supply has been established, in many
parts of India, where formerly cholera was rife,
it now occurs very rarely and in a milder form.
In general, the atmosphere acts as a health
and life giver.
The more fresh air we breathe, the more we
dilute the poisons which would otherwise harm
We are no doubt temporarily and permanently
affected by the particular climate we live in, as
well as by the air we breathe.
Climate is an average of the general weather con-
ditions, and is chiefly determined by the tempera-
ture, rainfall, humidity, sunshine, and winds which
prevail in a district.
All the regular and irregular variations men-
tioned in chapters (IV.) and (VIII.) are involved,
particularly annual and daily temperature ranges.
At some seasons a change to a drier and
warmer climate such as that of Egypt or Colo-
rado is desirable.
Sometimes a mild one like that of Madeira or
New Zealand is recommended, while a return to
1 86 THE STORY OF THE EARTH'S ATMOSPHERE.
England or Europe is often indispensable to the
Anglo-Indian who has endured years of Indian
Permanent residence in different climates
tends to develop certain national characteristics.
Thus the dry, rapidly changeable, continental
climate of North America, accounts for the ac-
tivity and impulsive go-aheadness by which the
Americans are characterised. At the same time
it accounts for their liability to neuralgia.
The debilitating, nerveless lassitude of the
natives of tropical coasts is directly due to the
moisture and heat.
The dry heat of central India and Arabia de-
velopes the martial energy of the Sikh and the
Bedouin, while the mild but cool and temperate
climate of England and Western Europe is dis-
tinctly accountable for the well-balanced mental
and physical development of the races which
have hitherto ruled the world.
Climates may be hot or cold, moderate or ex-
treme (i. e., of small or large range), dry or damp,
calm or boisterous.
It was formerly deemed sufficient to pay at-
tention to the temperature alone, but it has now
been found that the other factors are equally
Even in regard to temperature, the average
for the year is no safe criterion. The average
is an artificial centre, round which the values
oscillate, and may be very seldom experienced.
The ranges are far more important.
Thus Calcutta, in Bengal, has the same mean
temperature of 77.7 F., as Agra, in the North-
West Provinces, but their climates are very dif-
ferent when the ranges of temperature are con*
, LIFE IN THE ATMOSPHERE. 187
sidered. The difference of average temperature
between the hottest and coldest months at Agra
is 34, at Calcutta only 20. The average daily
range at Agra is about 30, at Calcutta only 16.
When we touch rainfall and humidity we find
Agra has only 29 inches to Calcutta 65 inches;
while if 5 represents the humidity at Agra, 8 rep-
resents the amount at Calcutta. Agra also has
half the cloud, and therefore about double the
bright sunshine of Calcutta. Such instances could
be multiplied indefinitely.
Here, therefore, we have two places situated
in the same river valley, only 4 of latitude apart,
and yet with totally different climates.
To attempt to group climates together over
large areas is therefore impossible, except very
The old divisions of one torrid, two temperate
and two arctic zones served as a rough outline.
They are totally inadequate to explain the varia-
tions found at places not far apart within the
The only way to gain an idea of the climate
of a place, apart from a study of actual figures,
is to have a clear idea of the effects of all the
different factors, such as
(2) Hemisphere, north or south.
This makes a great difference. The tempera-
ture ranges are far smaller in the Southern
(3) Situation with respect to large continents,
particularly east or west. If on the east, as the
U. S. or China, the temperature ranges, daily and
seasonal, are much greater than on the west
1 88 THE STORY OF THE EARTHS ATMOSPHERE.
(4) Position, oceanic, coastal, or continental.
This affects both temperature range, and humid-
ity very largely.
(5) Elevation above the sea, and whether
isolated or on a tableland. If the former, the
climate is moderate; if the latter, extreme. In
both cases the general temperature diminishes
about i F. for every 300 feet of elevation above
(6) Situation with respect to neighbouring
mountain ranges, especially leeward or wind-
ward, with reference to prevailing winds. If on
the windward side, such as Mull, Coimbra in Por-
tugal, Vancouver, Bombay, Colombo, Valdivia in
Chili, Brisbane, and Chirrapunji in Assam, the
rainfall is often over 75 inches, while corre-
spondingly on the lee sides of the adjacent
ranges we find, Aberdeen, Salamanca (less than
ten inches), Cariboo (east of the Coast range),
Poona, Bandarawela, Bahia Blanca, Roma, and
Shillong, with amounts varying from 20 to 30
(7) Situation with respect to prevalent winds,
trades, anti-trades, monsoons. This determines
the season of rain, such as the monsoon rains in
the Indian summer, whereas the summer in Aus-
tralia, exposed to the trades, is the dry season.
The temperature conditions are thus consider-
(8) The neighbouring oceanic currents. The
effects of these have already been alluded to on
(9) The nature and covering of the adjacent
(10) Situation with respect to the tropical or
circumpolar rain and wind-belts.
LIFE IN THE ATMOSPHERE.
As types of various general climates at sea-
level, the following may serve as illustrations.
(2) Tropical, lat. 10 to 23
Hot, moist, equable, sa-
r , . ( Similar to (i) but less
Htg'K'ong, j ^able aU salubri-
Jfhore. } Hot , dry, and extreme,
(J) Inland, 1 M^ndalay, j" p**' exce P l in win '
1 Timbuktu, J ten
f Riviera, f Temperate and dry,
(3) Sub - Trop - S. California, owing to position be-
ical, lat. 23 to -i Cape Colony, -^ tween tropical and
lat. 35, j Southern Aus- polar rain-belts, very
(_ tralia, [ salubrious.
Cool, moist, and equable
(a) North, lat. I United States,
35 to lat. 6o,1 Central Siberi ' a>
> near sea, dry and ex-
L and China,
(6) South, lat.
35 to lat. 50,
Cool, moist, and equa-
ble, most salubrious
in the world.
(5) Polar, lat.
60 to poles,
N. Siberia, j Cold and fairly dry, ex
Greenland, ( treme inland.
Judged by averages alone, a climate with an
annual average temperature between
75 and 85 is hot.
65 " 75 is warm.
55 " 65 is mild.
50 " 55 is temperate.
40 " 50 is cold.
Below 40 is arctic.
I po THE STORY OF THE EARTH'S ATMOSPHERE.
These adjectives are, however, only applica-
ble when the range is small between summer and
Man can never hope to control or sensibly
alter the climate of the countries in which he is
placed. Nature works on too vast a scale. He
can, however, by studying the different kinds of
climate and their properties, discover which are
suitable for certain diseases and ages, and by
utilising this knowledge, to some extent shelter
himself against influences which are recognised
to be hostile, and which lead not merely to loss
of individual life and health, but to degeneration
of the human race.
Abbe, Professor, 105.
Abercromby, Ralph, in.
Albatross, flight of, 168, 170.
Ammonia in atmosphere, 18, 21.
Boyle's law, 95, 98.
Brocken, Spectre of the, 148.
Bull's-eye squall, 150.
Buys Ballot's law, 128.
Anticyclones, 29, 127, 132, 134.
Arched squall, 150, 162.
Argon in atmosphere, 18.
Carbonic acid, 18, 20.
Atmosphere, composition, 17;
electricity, 159; height, 9, 14;
history, 9; laws, 94; life in,
Cavallo, Thomas, 163.
Chanute, Octave, 166.
183; movements (winds), 64;
Charles, law of, 96, 98.
optics of, 141; origin, 9; pres-
sure, 15, 16, 25; sounds of, 141;
temperature, 31 ; weight, 15,
Cirrus, high. See Clouds.
Aurora borealis, 148.
Clouds, 99, 106, 119; cirro-cu-
mulus, in; cirro-stratus, in.
114, 145, 156; cirrus, no, in,
114, 117, 118, 144; cumulus, 100,
Bacilli, nitrogen abstracting, 20.
no, in, 117, 118; cumulo-nim-
Back, Admiral, 173.
bus, in; formation of, 22;
Baden Powell, 177.
forms of, no: height of, 111,
118; high-cirrus, 106; nimbus,
Balloons, 15, 88, 93, 163.
in, 114; stratus, no, ill, 114,
Ballot, Dr. Buys, 128.
117; strato-nimbus, in; veloc-
Barometer, 16, 25.
Barometric pressure, variations
ity of movement, 117.
in, 27, 58, 68, 81.
Berson, Dr., balloon ascension,
Colour of the sky, 25, 102, 141.
Colours, sunset, 103.
Convection currents, 104, 158.
Birds, flight of, 166.
Conservatism of energy, 97.
" Corpse candle," 148.
Courant, ascendant, 59.
Blue Hill Observatory, 92, 118,
Coxwell, balloon ascension, 15,
1 60, 174.
Blueness of sky, 102.
Cumulus. See Clouds.
Cumulus, festooned, 156.
Currents, ocean, 46, 60, no.
Cyclones, 29, 59, 79, 84, 99, 125.
Hargrave, 166, 170, 177.
Hargrave kite, 170.
Davis, Professor, 153.
Haughton, Dr., 60.
Hawk, flight of, 167.
Heat, 31, 97, 142.
Diffusion of gases, too.