1 By means of which the machine is tilted sideways.

2 Anti-aircraft or high-angle guns on the ground.

3 All flying machines were known as “grids” in the squadron.

4 The F.E.8 was a “pusher” machine, that is with the engine and propeller behind the pilot. It was used for reconnaissance work at this time, but later became one of our night-bombing aeroplanes.

5 Used for signals. It fired a kind of cartridge from which a flaming ball was discharged of red, green, or white lights.

6 The weekly official record of work done by the R.F.C., including all scraps in which the Hun “crashed” or “went down out of control.”

7 Anti-aircraft guns or shells.

8 It is very difficult to fly by compass in clouds for any length of time.

9 Kite balloon.

10 These machines were some of the first to be used for reconnaissance purposes. They did about ninety miles an hour “all out,” and were therefore difficult to handle against the faster Albatros. It is very often the duty of reconnaissance machines not to engage in a fight, as their news may be lost.

11 When every machine gets mixed up in a sort of mÊlÉe.

12 Either of the D3 or D5 type, which was generally used by the enemy at this time. It was an efficient machine for speed, but could not climb as well as our scouts.

13 A machine is spinning when it is diving towards the ground turning in a corkscrew fashion.

14 Most fighting is now done in “formation,” that is in an organised pack. Either the machines fly in the shape of a wedge or a diamond, or in some order which is most convenient to the “leader.”

15 It is very often impossible to watch a machine after it has been hit until it “crashes.” It is, therefore, counted as out of control. Sometimes this was used as a “blind” by some pilots to escape. They simply let the machine do what it liked, and when near the ground took control again.

16 A vehicle used for moving dismantled aeroplanes by road.

17 A pet name used for artillery machines of the B.E. type.

18 The Huns always used to bombard certain areas in the morning and evening. These bombardments were known as the morning and evening hate.

19 These rockets were invented by a Frenchman and used for balloon strafing. They were placed in cases on the struts, and were fired by electricity. The rocket was about 1½ feet long and the stick about 3 feet.

20 These are used, generally in the ratio of one to four ordinary or armour-piercing bullets, to show the general direction in which the burst of fire is going. Instead of being filled with lead like the ordinary bullet, they contain phosphorus, which commences to burn as soon as the bullet is discharged from the machine gun, and leaves behind it a trail of smoke and fire to mark its course.

21 A number of balls of fire fastened together and shot up into the air in order to fall over the attacking machine and bring it down in flames.

22 A type of machine gun. The bullets are fed from a “drum” which is automatically turned when the gun fires.

23 The tail plane which is used to direct the machine up or down.

24 Tennis.

25 A pilot who has brought down five or more enemy machines.

26 Corresponds to an Adjutant in an infantry battalion.

27 Bishop.

28 A.M.L.O.: Assistant Military Landing Officer.

29 Bishop, who got his V.C. for this.

30 An indefinitely large number.

31 Trick flying.

32 A formidable line of trenches branching off from the main Hindenburg line of QuÉant and defending Douai.

33 A stream flowing north of Arras.

34 Same as wind up, or fright.

35 One of the most famous formations of enemy scouts, composed of the “crack” German pilots. Their machines generally had red bodies.

36 A piece of aluminium shaped so as to cover the engine.

37 A main plane is made up of two spars on which the ribs are fixed.

38 Body of the machine.

39 A barbarous word invented by the Army, and which means “alighting from an omnibus.”

40 This, I am afraid, is not quite accurate, as a glance at Appendix II will show.

41 Ypres.

42 Cassel.

43 A type of hangar invented by a Frenchman and generally used on our aerodromes in France.

44 A method used to bring a machine down quickly without gaining speed.

45 Air mechanics.

46 Bishop.

47 Scott.

48 Scott.

49 G.L. Lloyd.

50 Penny.

51 The S.E.5s.

52 Bishop.

53 Bishop.

54 Home Establishment.