“Great Scott, Tom!  You don’t suppose any one wanted that shaft to fall on you; do you?”

“No, I don’t believe that.  Probably some one wanted to damage the shaft, or he might have thought it would topple over against the bench, and break some of my tools, instruments or machinery.  I do delicate experiments here, and it wouldn’t take much of a blow to spoil them.  That’s why those cords were cut.”

“Who did it?  Do you think Andy Foger—­”

“No, I think it was the man Koku thought was a chicken thief, and whom we chased the other night.  I’ve got to be on my guard.  I wonder if—­”

Tom was interrupted by the appearance of Koku, who came out of the shop with a letter the postman had just left.

“I don’t know that writing very well, and yet it looks familiar,” said Tom, as he tore open the missive.  “Hello, here’s more trouble!” he exclaimed as he hastily read it.

“What’s up now?” asked Ned.

“This is from Mr. Period, the picture man,” went on the young inventor.  It’s a warning.”

“A warning?”

“Yes.  He says: 

“’Dear Tom.  Be on your guard.  I understand that a rival moving picture concern is after you.  They want to make you an offer, and get you away from me.  But I trust you.  Don’t have anything to do with these other fellows.  And, at the same time, don’t give them a hint as to our plans.  Don’t tell them anything about your new camera.  There is a lot of jealousy and rivalry in this business and they are all after me.  They’ll probably come to see you, but be on your guard.  They know that I have been negotiating with you.  Remember the alarm the other night.’”

CHAPTER VI — TRYING THE CAMERA

“Well, what do you think of that?” cried Ned, as his chum finished.

“It certainly isn’t very pleasant,” replied Tom.  “I wonder why those chaps can’t let me alone?  Why don’t they invent cameras of their own?  Why are they always trying to get my secret inventions?”

“I suppose they can’t do things for themselves,” answered Ned.  “And then, again, your machinery always works, Tom, and some that your rivals make, doesn’t.”

“Well, maybe that’s it,” admitted our hero, as he put away the letter.  “I will be on the watch, just as I have been before.  I’ve got the burglar alarm wires adjusted on the shop now, and when these rival moving picture men come after me they’ll get a short answer.”

For several days nothing happened, and Tom and Ned worked hard on the Wizard Camera.  It was nearing completion, and they were planning, soon, to give it a test, when, one afternoon, two strangers, in a powerful automobile, came to the Swift homestead.  They inquired for Tom, and, as he was out in the shop, with Ned and Koku, and as he often received visitors out there, Mrs. Baggert sent out the two men, who left their car in front of the house.