of　getting　the　range　of　a　hidden　battery；
  or　a　massed　force　in　his　front。　The　observer　in
  the　aeroplane　will　sail　over　the　area　at　an　understood
  altitude；　say　one　mile　in　height。
  The　officer　in　charge　of　the　battery；　knowing
  the　height　of　the　airship；　is　able；　by　means　of
  the　angle　thus　given　him；　to　get　the　distance　between
  his　battery　and　the　concealed　point　beneath
  the　airship。　The　observer　in　the　airship；　of
  course；　signals　the　engineer　officer；　the　exact　point
  or　time　when　the　airship　is　directly　above；　and
  this　gives　him　the　correct　angle。
  The　guns　of　the　battery　are　then　directed　and
  fired　so　as　to　reach　the　concealed　point。　It　is
  now　important　to　be　able　to　send　intelligible　signals
  to　the　officer　in　charge　of　the　battery。　If　the
  shot　goes　beyond　the　mark；　the　observer　in　the
  airship　raises　the　flag　above　his　head；　which　indicates
  that　it　was　too　high。
  HOW　USED。If　the　shot　fell　short　he　would
  lower　the　flag。　If　the　shot　landed　too　far　to　the
  right；　this　would　be　indicated　by　the　flag；　and　if
  too　far　to　the　left；　the　signal　would；　in　like　manner；
  be　sufficient　to　enable　the　gunners　to　correct
  the　guns。
  When　the　exact　range　is　obtained　the　observer
  in　the　ship　waves　the　flag　about　his　head；　in
  token　of　approval。　All　this　work　of　noting　the
  effect　of　the　shots　must　be　taken　while　the　airship
  is　under　fire；　and　while　circling　about　within
  visual　range　of　the　concealed　object　below。
  The　officer　in　charge　of　the　battery；　as　well　as
  the　observer　on　the　flying　craft；　must　be　equipped
  with　powerful　glasses；　so　the　effect　of　the　shots
  may　be　noted　on　the　one　hand；　and　the　signals
  properly　read　by　the　officer　on　the　other　hand。
  It　may　be　said；　however；　that　air　battles　have
  not　been　frequent　and　that　they　have　been　merely
  incidents　of　the　conditions　under　which　they　were
  operated。　The　mission　of　the　aeroplane　is　now
  conceded　to　be　purely　one　of　observation；　such　as
  we　have　described。
  Both　French　and　German　reports　are　full　of
  incidents　showing　the　value　of　observations；　and
  also　concerning　the　effects　of　bombs。　Extracts
  from　the　diaries　of　prisoners　gave　many　interesting
  features　of　the　results　of　aeroplane　work。
  CASUALTIES　DUE　TO　AEROPLANES。In　the　diary
  of　one　was　found　the　remark：　〃I　was　lucky　to
  escape　the　bomb　thrown　by　a　French　aviator　at
  Conrobet；　which　killed　eight　of　my　companions。〃
  Another　says：　〃The　Seventh　Company　of　the
  Third　Regiment　of　the　Guard　had　eight　killed　and
  twenty…two　wounded　by　bomb　from　a　French　aeroplane。〃
  Another：　〃An　officer　showed　us　a　torn　coat
  taken　from　one　of　sixty　soldiers　wounded　by　a
  bomb　from　an　aeroplane。〃
  A　prisoner　says：　〃Near　Neuville　an　aeroplane
  bomb　dropped　on　a　supply　train；　killed　four　men；
  wounded　six；　and　killed　a　considerable　number　of
  horses。〃
  The　Belgians；　after　their　defeat　and　the　capture
  of　Antwerp；　were　forced　to　the　west　along
  the　coast。　In　some　way　they　learned　that　the
  Kaiser　was　about　to　occupy　a　chateau　near　Dixmunde。
  Several　aviators　flew　above　the　position
  and　dropped　a　number　of　bombs　on　the　building；
  completely　wrecking　it；　and　it　was　fortunate　that
  the　Emperor　left　the　building　only　twenty　minutes
  before；　as　several　of　his　aides　and　soldiers
  on　duty　were　killed。
  On　numerous　occasions　the　headquarters　of　the
  different　commanders　have　been　discovered　and
  had　to　be　moved　to　safer　places。
  During　all　these　wonderful　exploits　which　will
  live　in　history　because　men　had　the　opportunity
  during　the　war　to　use　them　for　the　first　time　in
  actual　conflict；　the　official　reports　have　not
  mentioned　the　aviators　by　name。　The　deaths　of　the
  brave　men　have　brought　forth　the　acknowledgments
  of　their　services。　During　the　first　three
  months　of　the　war　it　is　estimated　that　over　sixty
  aviators　and　aides　had　lost　their　lives　in　the　conflict
  on　the　two　great　battle　lines。　This　does　not
  take　into　account　those　who　met　death　on　the
  Zeppelins；　of　which　five　had　been　destroyed　during
  that　time。
  THE　END
  GLOSSARY　OF　WORDS　USED　IN　TEXT　OF　THIS　VOLUME
  Where　a　word　has　various　meanings；　that　definition　is　given
  which　will　express　the　terms　used　by　the　author　in　explaining
  the　mechanism　or　subject　to　which　it　refers。
  Aviation。　The　art　of　flying。
  Altitude。　Height；　a　vertical　distance　above　any　point。
  Attraction。　The　art　or　process　of　drawing　towards。
  Allusion。　Referring　to　a　certain　thing。
  Assume。　Taking　it　for　granted。
  Accentuated。　To　lay　great　stress　upon　a　thing。
  Angle　of　Movement。　Any　direction　which　is　upwardly　or　downwardly；
  as　distinguished　from　the　direction　of　movement　which　is　either
  to　the　right　or　to　the　left。
  Acquire。　To　obtain；　to　recover；　to　procure。
  Analogous。　Corresponding　to　or　resembling　some　other　thing　or
  object。
  Air　Hole。　A　term　used　to　express　a　condition　in　flying　where　the
  machine　while　in　horizontal　flight　takes　a　sudden　drop；　due　to
  counter　currents。
  Ailerons。　Literally；　small　planes。　Used　to　designate　the　small
  planes　which　are　designed　to　stabilize　a　machine。
  Angle。　A　figure；　or　two　straight　lines　which　start　at　the　same
  point。　The　sides　of　these　lines　are　termed　the　angle。
  Analysis。　To　separate；　to　take　apart　and　examine　the　various
  parts　or　elements　of　a　thing。
  Aeroplane。　Any　form　of　machine　which　has　planes；　and　is　heavier
  than　air。　Usually　a　flying　structure　which　is　propelled　by　some
  motive　power。
  Accumulation。　Adding　to；　bringing　together　the　same　or　unlike
  articles。
  Ascribable。　A　reference　to　some　antecedent　source。
  Aeronautics。　The　science　of　flying。
  Anterior。　Meaning　the　front　or　forward　margin　or　portion　of　a
  body。
  Artifices。　Any　artificial　product；　or　workmanship。
  Axially。　Through　the　central　portion。　Thus；　the　shaft　which　goes
  through　a　cylinder　is　axially　arranged。
  Automatic。　A　thing　which　operates　by　its　own　mechanism；　a
  contrivance　which　is　made　in　such　a　manner　that　it　will　run
  without　manual　operation　or　care。
  Alertness。　Quick；　being　active。
  Apex。　The　point　at　which　two　lines　meet；　also　the　extreme　pointed
  end　of　a　conical　figure。
  Ascension。　Moving　upwardly。
  Accessories。　The　parts　of　a　machine；　or　artielee　which　may　ha
  used　in　connection　therewith。
  Anemometer。　An　instrument　for　measuring　the　force　or　the　velocity
  of　wind。
  Anemograph。　An　instrument　that　usually　traces　a　curved　line　OH
  paper　to　make　a　record　of　the　force　or　direction；　or　velocity　of
  the　wind。
  Anemometrograph。　A　device　which　determines　the　force；　velocity
  and　direction　of　the　wind。
  Accretion。　Adding　to　little　by　little。
  Accelerated。　Quiekening；　hurrying　the　process。
  Abridged。　Partly　taken　away　from；　shortened。
  Abrogate。　To　dispense　with；　to　set　aside。
  Abnormal　Not　in　the　usual　manner；　not　in　a　regular　way。
  Alternate。　First　one　and　then　another；　going　from　one　side　to　the
  other。
  Ancient　Lights。　An　old　English　law　which　prevents　a　neighbor　from
  shutting　off　sunlight。
  Angularly。　A　line　which　runs　out　from　another　so　that　the　two　are
  not　parallel。
  Aneroid。　Not　wet。　Applied　to　the　type　of　barometer　where　the
  medium　for　determ；ining　the　pressure　is　not　made　of　mercury。
  Aspirate。　A　term　given　by　the　French　to　that　peculiar　action　of
  wing；　or　other　body；　which；　when　placed　in　certain　positions；
  relative　to　a　current　of　air；　will　cause　it　to　be　drawn　into　the
  current。
  Assemblage。　The　bringing　together　of　the　parts　or　elements　of　a
  machine。
  Augment。　To　aid；　to　add　to　or　increase。
  Banked。　The　term　used　in　aviation　which　indicates　that　the
  machine　is　turned　up　so　that　its　supporting　surfaces
  rest　against　the　air；　as　in　alighting。
  Barometer。　An　instrument　for　determining　the　air　pressure；　and
  thereby　indicating　altitudes。
  Bevel　Pinion。　A　toothed　wheel　driven　by　a　larger　wheel。
  Bi…Plane。　Two　planes。　In　aviation　that　type　which　has　two　planes；
  similar　in　size；　usually；　and　generally　placed　one　above　the
  other　so　they　are　separated　the　same　distance　from　each　other；　as
  the　width　of　each　of　the　planes。
  Bulge。　A　hump；　an　enlargement　beyond　the　normal　at　any　point。
  Camber；　also　Cambre。　The　upward　curve　in　a　plane。
  Catapult。　A　piece　of　mechanism　for　projecting　or　throwing　a
  missile。
  Carbureter。　The　device　which　breaks　up　the　fuel　oil；　and　mixes
  the　proper　quantity　of　air　with　it　before　it　is　drawn　into　the
  engine。
  Catastrophe。　A　calamity；　a　sad　ending；　loss　of　life　or　of
  property。
  Cellular。　Made　up　of　small　hollows；　or　compartments；　filled　with
  holes。
  Celestial。　Pertaining　to　the　heavens。
  Centrifugal。　That　force　which　throws　outwardly　from　a　rotating
  body。
  Centripetal。　That　force；　like　the　attraction　of　gravity；　which
  draws　a　body　to　the　center。
  Characteristic。　Striking；　that　which　is　peculia