"The Miss Bonner Birthday Present Fund. I'm the Cus--Cus--Custodium." "The what kind of cuss?" asked Dr. Bennett, who had just poked his head in at the door to ask if, by any chance, Mabel had seen anything of his hair brushes. "The Custodium," replied Mabel, with dignity. "I think she means 'Custodian.'" explained Mrs. Bennett, rescuing the brushes. "Well," retorted Mabel, "the toad part was all right if the tail wasn't. Marjory named me that, and she's always using bigger words than she ought to." "So is somebody else," said Dr. Bennett, forgetting to scold about the brushes. "But I think the 'Custodium' had better hurry, or she'll be late for school." That was Friday, and the little brown purse contained two dollars and forty-seven cents, which seemed a tremendous sum to inexperienced Mabel. She remembered afterwards how very big, imposing and substantial the school building had looked that morning as she approached it and noticed some strangers fingering the "rain-drops" to see if they were real. Indeed, everybody, from the largest tax-payer down to the smallest pupil, was proud of that building because it was so big and because there was no more rain-drop sandstone left in the quarry from which it had been taken. Even thoughtless Mabel always swelled with pride when tourists paused to comment on the queer, spotted appearance of those massive walls. She meant to point that building out some day to her grandchildren as the fount of all her learning; for the huge, solid building looked as if it would certainly outlast not only Mabel's grandchildren but all their great-great-grandchildren as well. But it didn't. The catastrophe came on Saturday. Afterwards, everybody in Lakeville was glad, since the thing had to happen at all, that the day was Saturday, for no one liked to think what might have happened had the trouble come on a schoolday. It was also a Saturday in the first week of November, which was not quite so fortunate, as there was a stiff north wind. At two o'clock that afternoon the streets were almost deserted, but weatherproof Dick Tucker, with his hands in his pockets, was going along whistling at the top of his very good lungs. By the merest chance he glanced at the wide windows of Lakeville's most pretentious possession, the big Public School building. From four of the upper windows floated thin, softly curling plumes of gray smoke. The windows were closed, but the smoke appeared to be leaking out from the surrounding frames. "Hello!" muttered Dick, suddenly shutting off his whistle. "That looks like smoke. The janitor must be rebuilding the furnace fire. But why should smoke--I guess I'll investigate." The puzzled boy ran up the steps, pulled the vestibule door open and eagerly pressed his nose against the plate-glass panel of the inner door, which was locked. Through the glass, however, he could plainly see that the wide corridor was thick with smoke. He could even smell it.