knaw ma duty, Mister Carter—A'm the offeecial boaster o' the wing an' the coor, an' whin they bring me doon wi' a bullet in ma heid, A' hope ye'll engage anither like me."

"There isn't another like you, Tam," laughed Carter.

"Ye dinna knaw Glasca,'" replied Tam darkly.

Lieutenant Carter went up on "a tour of duty" soon after and Tam was on the ground to watch his departure.

"Tam," he shouted, before the controls were in, "I liked that cigar—I'll take fifty from you to-night."

"Ower ma deid body," said Tam, puffing contentedly at the very last inch of his own; "the watch-wairds o' victory are 'threeft an' economy'!"

"I've warned you," roared Carter, for now the engine was going.

Tam nodded a smiling farewell as the machine skipped and ran over the ground before it swooped upward into space.

He went back to his room, but had hardly settled himself to the examination of a new batch of blood-curdling literature before Blackie strode in.

"Mr. Carter's down, Tam," he said.

"Doon!"

Tam jumped up, a frown on his face.

"Shot dead and fell inside our lines—go up and see if you can find Müller."

Tam dressed slowly. Behind the mask of his face, God knows what sorrow lay, for he was fond of the boy, as he had been fond of so many boys who had gone up in the joy and pride of their youth, and had earned by the supreme sacrifice that sinister line in the communiques: "One of our machines did not return."

He ranged the heavens that day seeking his man. He waited temptingly in reachable places and even lured one of his enemies to attack him.

"There's something down," said Blackie, as a flaming German aeroplane shot downward from the clouds. "But I'm afraid it's not Müller this time."

It was not. Tam returned morose and uncommunicative. His anger was increased when the intercepted wireless came to hand in the evening:

"Captain Müller shot down his twenty-seventh aeroplane."

That night, when the mess was sitting around after dinner, Tam appeared with a big armful of cigars.

"What's the matter with 'em?" asked Blackie in mock alarm.

"They're a' that Mister Carter bocht," said Tam untruthfully, "an' A' thocht ye'd wish to ha'e a few o' the laddie's seegairs."

Nobody was deceived. They pooled the cigars for the mess and Tam went back to his quarters lighter of heart. He slept soundly and was wakened an hour before dawn by his batman.

"'The weary roond, the deely task,'" quoted Tam, taking the steaming mug of tea from his servant's hands. "What likes the mornin', Horace?"

"Fine, Sergeant—clear sky an' all the stars are out."

"Fine for them," said Tam sarcastically, "they've nawthin' to do but be oot or in—A've no patience wi' the stars—puir silly bodies winkin' an' blinkin' an' doin' nae guid to mon or beastie—chuck me ma breeches an' let the warm watter rin in the bath."

In the gray light of dawn the reliefs stood on the ground, waiting for the word "go."

"A' wonder what ma frien' MacMuller is thinkin' the morn?" asked Tam; "wi' a wan face an' a haggaird een, he'll be takin' a moornfu' farewell o' the Croon Prince Ruppect.

"'Ye're a brave lad,' says the Croon Prince, 'but maybe Tam's awa'.'

"'Naw,' says MacMuller, shakin' his heid, 'A've a presentiment that Tam's no' awa'. He'll be oop-stairs waitin' to deal his feelon's-blow. Ech!' says Mister MacMuller, 'for why did I leave ma fine job at the gas-wairks to encoonter the perils an' advairsities of aerial reconnaissance?' he says. 'Well, I'll be gettin' alang, yeer Majesty or Highness—dawn't expect ma till ye see ma.'

"He moonts his graind machine an' soon the intreepid baird-man is soorin' to the skies. He looks oop—what is that seenister for-rm lairking in the cloods? It is Tam the Comet!"

"Up, you talkative devil," said Blackie pleasantly.

Tam rode upward at an angle which sent so great a pressure of air against him that he ached in back and arm and legs to keep his balance. It was as though he were leaning back without support, with great weights piled on his chest. He saw nothing but the pale blue skies and the fleecy trail of high clouds, heard nothing but the numbing, maddening roar of his engines.

He sang a little song to himself, for despite his discomfort he was happy enough. His eyes were for the engine, his ears for possible eccentricities of running. He was pushing a straight course and knew exactly where he was by a glance at his barometer. At six thousand feet he was behind the British lines at the Bois de Colbert, at seven thousand feet he should be over Nivelle-Ancre and should turn so that he reached his proper altitude at a point one mile behind the fire trenches and somewhere in the region of the Bois de Colbert again.

The aeronometer marked twelve thousand feet when he leveled the machine and began to take an interest in military affairs. The sky was clear of machines, with the exception of honest British spotters lumbering along like farm laborers to their monotonous toil. A gentlemanly fighting machine was doing "stunts" over by Serray and there was no sign of an enemy. Tam looked down. He saw a world of tiny squares intersected by thin white lines. These were main roads. He saw little dewdrops of water occurring at irregular intervals. They were really respectable-sized lakes.

Beneath him were two irregular scratches against the dull green-brown of earth that stretched interminably north and south. They ran parallel at irregular distances apart. Sometimes they approached so that it seemed that they touched. In other places they drew apart from one another for no apparent reason and there was quite a respectable distance of ground between them. These were the trench lines, and every now and again on one side or the other a puff of dirty brown smoke would appear and hang like a pall before the breeze sent it streaming slowly backward.

Sometimes the clouds of smoke would be almost continuous, but these shell-bursts were not confined to the front lines. From where Tam hung he could see billowing smoke clouds appear in every direction. Far behind the enemy's lines at the great road junctions, in the low-roofed billeting villages, on the single-track railways, they came and went.

The thunder of his engines drowned all sound so he could not hear the never-ceasing booming of the guns, the never-ending crash of exploding shell. Once he saw a heavy German shell in the air—he glimpsed it at that culminating point of its trajectory where the shell begins to lose its initial velocity and turns earthward again. It was a curious experience, which many airmen have had, and quite understandable, since the howitzer shell rises to a tremendous height before it follows the descending curve of its flight.

He paid a visit to the only cloud that had any pretensions to being a cloud, and found nothing. So he went over the German lines. He passed far behind the fighting front and presently came above a certain confusion of ground which marked an advance depot. He pressed his foot twice on a lever and circled. Looking down he saw two red bursts of flame and a mass of smoke. He did not hear the explosions of the bombs he had loosed, because it was impossible to hear anything but the angry "Whar—r—r—!" of his engines.

A belligerent is very sensitive over the matter of bombed depots, and Tam, turning homeward, looked for the machines which would assuredly rise to intercept him. Already the Archies were banging