many times it was possible to
trace a crook by the tools he used. Once Mr. Nichols had apprehended a
kidnapper by means of a ransom note which had been written upon a
typewriter with a characteristic imprint. Penny hoped that the scraps
of metal might upon scientific analysis disclose the type of instrument
which had been employed by the thief to sever the tire standard.

"I'll drive directly to Dad's office and see if he can make use of any
of these old pieces," she decided.

Although the errand provided an excellent excuse, the real purpose of
her call was to learn if Jerry Barrows had kept his appointment.

Mr. Nichols was busy in the inner office when Penny arrived, but Miss
Arrow, the efficient secretary, told her that she might go in. She
found the detective engrossed in studying a group of photographs and
their accompanying Bertillon records.

"Trying to brush up on who's out and why?" Penny asked banteringly.

Mr. Nichols nodded as he offered a photograph for her inspection.

"This is one of the men who I think may be involved in the automobile
accessory thefts."

"Not a very pretty face," Penny commented.

"No, and 'Rap' Molberg hasn't a very pretty record either. He's served
several terms in the pen, though usually he's a little too smart to
have anything proven against him. Rap is the ringleader of the well
known Molberg gang. It begins to look as if the outfit had extended
its activities to Belton City."

"Is this Rap's description?" Penny inquired, indicating the Bertillon
record which lay upon the desk. It consisted of a bewildering array of
figures.

1.67.6 1.74.0 88.1 19.0 14-5
HGT OA TR HL HW

"Can you decipher it?" Mr. Nichols smiled.

"I know the HGT stands for height and TR for trunk, but what are the
other abbreviations?"

"OA means outer arm," the detective explained. "HL represents head
length and HW indicates the head width. Of course all the measurements
are reduced to meters, centimeters, and millimeters."

"It looks complicated."

"Not after you become accustomed to it. For instance, I can see at a
glance that Rap Molberg is five feet and seven-eighths inches tall--or
as it appears in Bertillon--one meter, sixty-seven centimeters and six
millimeters."

"I don't believe I'll ever care to be a detective," Penny smiled.
"It's too much like studying the multiplication table!"

"Crime detection is a scientific p