Wolfe, put their wits to work to perfect a glass that would reduce the chances of injury from this source.

How crude the experiments were at the beginning, only the inventors know. Unskilled in experimental chemistry, they naturally failed in their first attempts. A detective, to be successful, needs to be quickwitted enough to grasp a situation in the smallest possible time, and the two experimenters were among the most quick-witted of their craft.

They sought advice, and it was gladly given to them, although the well-meaning advisers laughed knowingly at the two would-be inventors. But they persevered and, with each experiment, learned more about the process, until, one fine day, the test-shooting at the glass with an army revolver worked to perfection. In dis

Gilliams Service

One of the features that recommends this unbreakable glass is its transparency. When a bank, for instance, has been furnished with it, no hold-up man could tell that the tellers' windows are not of the ordinary glass, and a big surprise is in store for him should he attempt to shatter it.

When the two coworkers had perfected this invention, they realized that banking institutions could not be expected to install the safety glass without a thorough test. A spectacular method was used, therefore, to prove its resistance. Commissioner Faurot, in the rifle-range of Police Headquarters, fired two .45-caliber steel-jacketed bullets from a revolver at short range at a piece of the glass. The effect is shown in the accompanying illustration. The glass was cracked, but it was not penetrated, andwhat was regarded as highly important-it did not shatter and fly. As a further test, the cracked glass was laid on the floor and a 24-pound iron dumb-bell was dropped upon it, without any further damage being apparent.

for gas-mask lenses, and 11,000,000 pieces were supplied to the Chemical Warfare Service, Gas Defense Section. This glass was of the bullet-proof variety, although it was made as thin as possible.

For the American and Allied airplanes, ten thousand pieces of the non-shatterable variety were made into wind-shields and served their purpose well in the last months of the war, as the Germans, with all their inventive genius, could not duplicate the process.

The practical value of the non-shatterable glass was demonstrated recently when an automobile collided with a heavy truck. The safety-glass wind-shield was bent, but not broken. This variety would be especially useful for shop windows; and show-cases containing diamonds and other precious stones could be made of it, insuring the safety of their contents.

JAMES ANDERSON.

The sleek body is in reality built of chromenickel steel, and inside the top are chromenickel steel shutters that slide down on roller bearings and cover the windows. Another steel shutter is placed behind the driver's seat. A special bracket is provided at the right-hand side for a machine-gun. Automatics or rifles can be fired through the loopholes at the sides and rear of the tonneau.

Provision is also made for a special bodyguard of six men. Swivels, with belts attached, are fastened above the runningboard, so that three soldiers can be strapped to each running-board; their hands thus being left free for their weapons.

The windows were made of a special glass that will not splinter under bullet-fire described in the opposite column of this page. The machine, delivered, cost more than thirty thousand dollars.

GEORGE F. PAUL.