group of listeners.

"It's a riot among the Poles," said Mrs. Barlow. Emily and Robert at once joined the group in the bay window.

"There he is!" shouted some one in the crowd, pointing, and immediately the covered heads became a sea of upturned faces—for the parlor was one flight up—foreign faces, inflamed with passion. A hatless father, brandishing a hatchet, led them on. But whither?

"They are breaking in our door!" shrieked Mrs. Barlow. "And Mr. Galuby at their head."

Almost instantly a volley of stones crashed against the side of the house and the windows were riddled. Emily and her mother drew back, with the whimpering little ones, but Robert stood his ground, watching old Galuby hacking at the door like a madman.

"What are you doing?" he called down, raising the sash.

There was a furious ring at the bell, followed by a snap, as if the cord were pulled out. A small pebble sailed through the open window and struck Robert in the cheek. At sight of the blood, though it was no more than a strawberry splash, Emily seized his arm.

"I must go down and stop this, Emily."

"No, Robert; they are savages when they get excited."

"What do they want?"

"Heaven knows! We have never quarreled with them!"

By this time the mob was augmented by swarms of gamins and roughs of the neighborhood, but a change of tone in the uproar indicated that there was some opposition to their mischief-making.

"It is the police who have come," said Mrs. Barlow, but Emily clung to Robert, so that he could neither approach the window nor go downstairs to the door without violence to the fragile girl he loved. For many minutes she held him there, till the murmurs below were mingled with shrieks of pain, and their dispersion and diminution told of the scattering of the crowd. Mrs. Barlow cautiously peeped out.

"They are arresting Mr. Galuby. He is covered with blood," she cried. Just then came a loud knocking at the front door. Robert tore himself free and ran down to open it. A police sergeant stepped inside.

"What is it all about?" asked Floyd.

"We'll give you safe escort to the cars. Hurry up!"

"Why should I be escorted?"

"Galuby's girl was killed in the fire and the Poles learned you were here."

"What of that?"

"Why, it's all over town that you set it."

CHAPTER IV.

THE INDEX FINGER POINTS.

John Davidson, the marshal, was officially supposed to be endowed with insight into the origin of fires. In fact, he drew a comfortable salary for pursuing no other occupation than this. A swift horse and a buggy enabled him to be among the first to arrive and a uniform of dark blue cloth, such as old sailors cling to, but with brass buttons for insignia in place of the little woven anchor that serves to remind the old salt of his element, entitled him to salutes from fire captains as well as from the rank and file. His written reports were read by insurance underwriters, and his wise shake of the head went a great way with those who knew little about fires and less about John Davidson.

For "old John Davidson," as he was generally known, had one failing which sadly impaired his official usefulness. He was an innate and inveterate optimist. The mild-blue eyes which beamed from behind his spectacles—old eyes, too, that no longer saw things as vividly as they used to—were meant to train fatherly glances on winsome children or dart gleams of approval at heroic hosemen whose sacrifices were rewarded by medal or purse. Indeed, he was very popular in both these functions, for old John Davidson had himself served his country and was comrade John of Sherman post, No. 5. But these kindly orbs were not those of the hawk, the lynx or the ferret, like Inspector McCausland's, of whose small gray pair, eyelets rather than eyes, rumor said that the off one contained a microscopic lens and its nigh fellow never went to sleep.

"John Davidson will never set the world on fire himself," Inspector McCausland had said when the veteran's nomination was first reported. Yet "old John" went his way cheerfully poohpoohing suspicion and really diffusing a globe of good feeling by his presence such as no fox in the police ranks could pretend to radiate.

However, the wisdom of the serpent is called for at times, as well as the meekness of the dove. When Marshal Davidson, against all proof and persuasion, gave out his intention to report the Arnold fire as accidental, originating in some unknown manner, or by spontaneous combustion, owing to the extreme heat of the day (the thermometer having registered 97), it was felt by his best friends that he allowed his optimism to blind him too far. He had made the same report in the Low street fire, the authors of which, an organized gang of blackmailers, trapped on another charge by McCausland, had just confessed their crime. Such laxity could only embolden the firebugs and encourage an epidemic of burnings. Something must be done, the police department thought, and when they selected Inspector McCausland to work up the case there was a general faith that something would be done.

By Sunday noon the inspector had gathered an array of data, sufficient to give a start to his active faculty of divination. Critics said that his one failing was a slight impatience in feeling his way to a conclusion, or, as his brother detectives expressed it, a tendency to "get away before the pistol shot."

"Going to hang some one, Dick?" asked Smith, whose specialty was counterfeiters.

"Well, we are sowing the hemp," answered McCausland, always ready with a jovial answer.

The first person upon whom suspicion rested was the Swedish housemaid, Bertha Lund. But it did not linger long, or with more than a moth-like pressure, on that robust and straightforward individual. Her story, thrice repeated in response to questions by the marshal, Chief Federhen, Inspector McCausland and the district attorney, had not varied a hair, although each time new details were added, as the questions of the different examiners opened new aspects of the affair.

"Prime proof of her honesty," said McCausland. "The rote story shrinks and varies, but never expands."

So the only fruit yielded by the ordeal which Bertha underwent was a thorough description of the house and household, pieced together from her replies, and McCausland had soon left her far behind in his search for a tenable theory.

The cook, Ellen Greeley, had not yet made her appearance. Bertha professed to have seen her dressing herself in her chamber and gave a clear description of her clothing, for the benefit of McCausland's note-book—green plaid skirt, brown waist, straw hat with red, purple and yellow pompons. Ellen was dressing "uncommonly rich" of late, they said. Bertha had talked with her upstairs and had heard the back door slam about the time when Ellen might be supposed to be departing. It had been the cook's holiday afternoon, and she was going to run over to her sister's, as she generally did, and return for supper, leaving Bertha to keep house.

But her sister had not seen her and she had not returned. A slow, heavy girl, rather apt to take the color of her mood from those around her, she seemed a creature who might be influenced to wrongdoing, but hardly the one to instigate it. So far as could be learned, the plain truth was romantic enough for Ellen Greeley, and she was not accustomed to embellish it with flowers of her own imagination. Nevertheless, after exhausting this subject, McCausland checked her name with the mental note "an accomplice, if anything," and the woman's prolonged absence, together with those "uncommonly rich" dresses she wore of late, the more he dwelt on them, prompted him the more to erase the modifying clause and let his mental comment stand "an accomplice."

But of whom? Ellen's sister and Bertha had both mentioned one Dennis Mungovan, the cook's sweetheart, who, until three weeks ago, had been coachman at the