IN THE last half of 1941, $15,000,000 worth of rubber was destroyed in a Massachusetts fire, a million dollars worth of food burned in Boston, and a $2,250,000 fire halted production of air- plane castings in Cleveland. Elsewhere, war machine factories burned to the ground, railroad wrecks occurred and power systems failed. Forests and grain fields burst into flame. Unfortunate accidents? Not all of them. Incendiarists and wreckers are busy trying to sap our strength. Enemy agents are loose in the United States. “The time has come for everyone to be on guard,” states Chief Lydell Peck, fire marshal of California. “Saboteurs don't necessarily confine their activities to plants engaged in defense work. Anything they can do to slow us down tends to reduce our rearmament effort.” Right now, Los Angeles county is the subversive hot spot of the United States because of the airplane construction, shipbuilding, and petroleum production congregated there. Recently Peck set up a laboratory in Los Angeles to deal exclusively with sabotage and arson and placed in charge of it Captain Paul Wolfe, nationally known arson expert. Protection of the Los Angdles industries really starts hundreds of miles awdy, in the mountains and deserts from which the area draws its water supply and electric power. Aqueducts and power lines extend for hundreds of miles, and all are guarded by vigilant patrols and by other means. What can you do in the fight against sabotage? Perhaps plenty, if you keep|your eyes open. If you live in the country, be on the lookout for clear glass marbles a little more than an inch in diameter that you may find lying on or near combustible material. Left alone, the “harmless” bits of glass may start disastrous fires. During the lastgvnr incendiarists started brush and forest fires by dropping “pancakes” of burlap pads soaked with self-igniting chemicals. Reading glasses set at an angle to catch the sun and trained on strips of celluloid were also used. This time, the glass marbles are appearing. A reading glass must be accurately focused to concentrate the sun’s rays, while a round marble has a universal focus and can start a fire no matter from what angle the sun strikes it. If you find any such marbles, gather them up carefully, handle | them with your handkerchief to preserve fingerprints, and report them to your fire or police department. Above all, be suspicious of any automobile that you think may have transported the marbles. Get its license number but don’t trust the number to memory. Write the numerals down at once. 1f you don't have a pencil, trace them in the dirt or with a finger on a dusty surface. Twelve bad “marble” fires occurred in the wake of one automobile in the northwest last fall before the car was finally traced. If you work in a defense factory your plant protection manager probably has instructed you in some of the ways to guard against wrecking and fire. Various “tools” used in the last war are being employed again. One favorite that looks innocent and is harmless as long as it is kept upright is the incendiary pencil. Laid on its side, within a few minutes it throws flames that may extend for 15 feet. Hidden inside are two thin glass vials, each open at the top and each containing a chemical. When the pencil is dropped the chemicals spill and combine, causing terrific combustion. Fake fountain pens are similarly used. Lead cigars, shaped and colored to resemble real cigars, work the same way. A saboteur is apt to place them in the hold of a ship and other places where delayed ignition will make the fires harder to fight. It may take days for the chemicals inside to eat through the lead sheath. For the last few months Wolfe has been conducting classes of instruction in scientific ways to prevent and detect sabotage. The classes are restricted to fire and peace officers and industrial safety men. It may be easy for a wrecker, as has happened, to crimp shut the fuel line of a training plane with pliers, causing the plane to crash soon after it has taken off. It’s just as easy to catch the malefactor if you know how. No two pairs of pliers are exactly alike under the microscope, Wolfe explains. Each pair leaves its individual signature just as the rifling of a gun leaves its particular mark on a bullet. Thus, the plier marks on the crimped fuel line from the wrecked plane can be compared with pliers used by every man who had access to the plane. If one man’s pliers are missing, that is enough to fasten suspicion on him. If none of the pliers agree with the markings on the fuel line, someone brought an extra pair to the field and there are other ways of tracing their ownership. It is better to prevent sabotage than to be a genius at nabbing suspects after the damage is done. Wolfe reminds his classes of the story about Napoleon, who is said to have put half the Paris police force at work scheming to assassinate him and the other half at work making certain such schemes could not succeed. With a little imagination, many of the loopholes for the saboteur can be closed. Wolfe points to some industrial plants that were thought to be foolproof simply because all employees had been fingerprinted and armed guards patrolled the fenced property. There still may be ways for sub- versive agents to tie such plants up. Sometimes the weakness is an outside water reservoir that supplies the plant, and is forgotten and unguarded. Suppose someone dumped sacks of cement into it some night to clog the outlet, possibly a few hours before a fire in the plant was to be set off. Such reservoirs should be illuminated, and their drainage lines protected by large bulging grilles. A saboteur doesn't need to pass through the gates if a plant’s electrical transformers are out on the street, where they often are. He can shut the power off and possibly put the transformers out of commission if they are within reach of his throwing arm. Again, watchmen are no protection if they patrol their beats at regular, predictable intervals. Watchmen’s tours should be on a varied schedule so that no one can tell when or where they will next appear. Protective systems such as burglar alarms or fire fighting apparatus should be put to use now and then to make sure they work. Such tests may reveal unsuspected faults, as was the case when firemen insisted on pretending there was a bad fire at a new shipyard. A six-inch water main served all points in the yard but when the firemen attached their lines and opened the hydrants, hardly enough water to quench a pile of burning rubbish flowed out. Fire apparatus would be useless if a real blaze started. Tracing down the trouble, it was found that the six-inch main was connected to the city water supply through a two-inch coupling. Fortunately the mistake was found and corrected before a real emergency happened. “One way a subversive agent gets by guards and fences is by intimidating an employee,” Wolfe says. “Bribery is relatively out of date; what a saboteur prefers is to find a hidden ‘skeleton’ in the history of some key employee and then through threats of exposure force the man to reveal secrets or participate in wrecking. When a trusted employee suddenly becomes depressed and nervous and seems to have a hidden fear, someone should find out what is on his mind. The chances are he will be merely run down or worried about his family, but it may be that he had been subjected to such threats. These days it doesn’t pay to take chances.”