With active service flying again, we enter into a new phase of which reconnaissance work occupies at least eighty per cent. of the time. Simply put, reconnaissance means flying over the other fellow’s lines to see what he is about, if he is massing troops at a certain point, or digging in new gun emplacements, or if there is any unusual activity on the highways and railways immediately behind his firing line. It is a difficult matter to differentiate between infantry and cavalry on the march; to distinguish a cleverly hidden gun emplacement, or to tell the difference between an ammunition and a supply depot. Bomb-dropping is a practice that requires the patience of a Job, good judgment, and a calm day--that is, if it is required to attain any degree of accuracy. Last, but not least, there is the matter of aerial combat, which, however, covers too wide a field for discussion in this short chapter. Thus, in the complete air-pilot, we have a blend of gunner, wireless expert, map-reader, amateur detective, and aviator. PART II ON ACTIVE SERVICE (Part II contains a series of incidents and adventures taken from the note-book of a British air pilot, stationed somewhere in the north of France, and are given in their original diary form.) CHAPTER IX BEHIND THE FIRING LINE _Somewhere in France, Friday._ Tucked away in a corner of an unused Flanders roadway, a long straggled line of irregular shaped huts and sheds surrounding a wide open meadow land, several acres in extent, is the aerodrome I have in mind. On either side are the long gaunt avenues of trees and in rear of them, bare and low-lying arable lands. No one can claim for it that it is a beauty spot. But it is comfortable, and above all one is able to obtain a bath there. On the right are the officers’ quarters: three long, low, wooden huts. Within, a passage runs along the center of the hut; and on either side of it are the various cabins, each about six feet square, and providing just sufficient space for a camp-bed, washstand and chair. A stove is at either end for warming purposes; and one bath is allotted to each hut. The mess-room is contained in a similar building across the way. The furniture is not such that one would meet with, say at the Ritz or the Savoy; but it serves its purpose. Three plain deal tables, each covered with a spotless cloth. A dozen or so stiff-back wooden chairs, and one solitary easy-chair. The competition for the latter is enormous. The general atmosphere of the place is cheery to a degree. Every member of the mess is full of good humor, quips and jests. Sub chaffs captain and captain chaffs sub, the while they attack plain wholesome fare with an unstinted vigor.