The Boy Volunteers with the French Airmen

xcitement. Several army divisions had come up in the night, and were bound for the Verdun sector, and from the information ob

duty. "Every man in the corps must report and be ready in the morning. Th

go to Verdun

orders at any mome

and some of those were now leaving, a few going directly east, on obse

ds, "that is equipped for carrying bombs, but I am told it is one of the speediest machines in the service. It

y in his eyes, remarked: "I think that will give us

replied Ralph, el

hat," said a vo

ntered unobserved. They saw by the smile on his face

e men are at work setting it up; so w

commandant's office, where they were provided with the receipt for the machine. The lieutenant remained here while Alfred carried the document to

sential requirements in inspecting. Naturally, the most important thing was to know that every part of the frame is not only properly set up and

er, it is usually corrected by letting out one or more sets of brace wires and taking up on others. This observation was followed by a careful look at the control planes. These are the sensitive parts of the plane, and may

t, and he drew himself up into the rear part of the chassis. "You will notice that this one rubs alo

ould weaken the br

are stranded, and as soon as one of the wires wears out by the frictional contact, an

an investigation was made of the engine. The mechanic turned it over to be sure that the compression was all right. Self-sta

e dashboard of an aeroplane is a much more wonderful contrivance than the dashboard of an au

d contrivances, which had been found desirable, some of which we

dy thing," said Alf

ich are supplied with them, but the order has been given

r?" asked Ralph, as he lo

ENT BOARD OF ST

Gages for two gasoline tanks 6. Dial to register engine revolutions. 7. Switches for two magnetos. 8. Air S

to observe the crossing point of the rod over the marked bar, and it will instantly tell what the angle of ascent or descent is. You see an aviator now

how fast the engine tu

e is that?"

ndred revolutions a minute, and the dial showed that the shaft was turning only one thou

ke an investigation at once without wait

mething is wrong, or a pain, which is nature's way to indicate that an inve

have on an automobile, but it is not a necessity. On a scouting and observation plane it is

id, "we could get

nant. "But why get along without it when

?" asked Ralph

ces, for one thing," a

e distance?" asked

er heard a boom, the distance could be determined almost instantaneously by roughly calculating 1,200 feet

t would be hard to tell about the boom from

ignaling," continued the lieutenant. "For instance, in sending information to a batte

w growing intensely interested in th

that altitude. The gunner will take the angle, set his piece and fire, the aviator, meanwhile, noting the course and effect of the shot. By means of the watch he

a glance how high the machine is flying, and Ralph looked at it with a somewhat doubtful expr

he altimeter can be relied

we found we were actually hundreds of feet less than the altimeter actually showed, so I am w

om Bar-le-Duc, the device we had showed 900 meters, for it was an automatically registering barometer, as

red at it at the

topographical charts, was 28 meters above sea level so I merely subtracted 28 from

action to know how high o

an aviator to know how high he is flying, if his mission is to conve

that done?"

ys we may have an opportunity to use the system, and I w

ng device, but at that the lieutenant shook h

accurate?" inquired

eed of the wind, are nearly perfect. That is not the difficulty. When it is used on a flying machine

main trouble?

e air speed to be ten miles, so that we were really going only fifty miles. If, now, the machine is turned so that we are going at right angles to the movement of the wind, although we may be going actually through the air at a speed of seventy miles an hour, the indicator does not register the air speed at all, bec

ay to tell how fast we

ties, will show a record of speed with the engine running at certain revolutions. An experienced aviator can judge pretty well, by experience, what the speed