The work progressed steadily—­not too hastily, but most satisfactorily.  Leaving at supper time, Bill’s eyes would sparkle as he talked over their efforts for that day, and quiet Gus would listen with nods and make remarks of appreciation now and then.

“The way we’ve made that panel, Gus, with those end cleats doweled on and the shellacking of both sides—­it’ll never warp.  I’m proud of that and it was mostly your idea.”

“No, yours.  I would have grooved the wood and used a tongue, but the dowels are firmer.”

“A tongue would have been all right.”

“But, dear boy, the dowels were easier to put in.”

“Oh, well, it’s done now.  To-morrow we’ll begin the mounting and wiring.  Then for the aerial!”

But that very to-morrow brought with it the hardest blow the boys had yet had to face.  Full of high spirits, they walked the half mile out to the Hooper place and found the garage a mass of blackened ruins.  It had caught fire, quite mysteriously, toward morning, and the gardener and chauffeur, roused by the crackling flames, had worked like beavers but with only time to push out the two automobiles; they could save nothing else.

The Hoopers had just risen from breakfast when the boys arrived; at once Grace came out, and her expressions of regret were such as to imply that the family had lost nothing, the boys being the only sufferers.  And it was a bit staggering—­all their work and machinery and tools and plans utterly ruined—­the lathe and drill a heap of twisted iron.  It was with a rueful face that Bill surveyed the catastrophe.

“Never mind, Billy,” said Grace, detecting evidence of moisture in his eyes; but she went over to smiling Gus and gazed at him in wonder.  “Don’t you care?” she asked.

“You bet I care; mostly on Bill’s account, though.  He had set his heart mighty strong on this.  I’m sorry about your loss, too.”

“Oh, never mind that!  Dad is ’phoning now for carpenters and his builder.  He’ll be out in a minute.”

Out he did come, with a shout of greeting; he, too, had sensed that the real regrets would be with them.

“It’ll be all right, me lads!” he shouted.  “Herring’ll be here on the next train, with a bunch o’ men, an’ I’ll git your dad, Gus, too.  Must have this building up just like it was in ten days.  An’ now count up just what you lads have lost; the hull sum total, b’jinks!  I’m goin’ to be the insurance comp’ny in this deal.”

“The insurance company!” Bill exclaimed and Gus stared.

“Sure.  Goin’ to make up your loss an’ then some.  I’m a heap int’rested in this Eddy’s son business, ain’t I?  Think I ain’t wantin’ to see that there contraption that hears a hunderd miles off?  Get busy an’ give me the expense.  We’ve got to git a-goin’.”

“But, Mr. Hooper, our loss isn’t yours and you have got enough to—­”

“Don’t talk; figger!  I’m runnin’ this loss business.  Don’t want to make me mad; eh?  Git at it an’ hurry up!” He turned and walked away.  Grace followed in a moment, but over her shoulder remarked to the wondering boys: