(f) Battery and Ignition
(1) Jam bits of wood into the ignition lock; loosen or exchange connections behind the switchboard; put dirt in spark plugs; damage distributor points.
(2) Turn on the lights in parked cars so that the battery will run down.
(3) Mechanics can ruin batteries in a number of undetectable ways: Take the valve cap off a cell, and drive a screw driver slantwise into the exposed water vent, shattering the plates of the cell; no damage will show when you put the cap back on. Iron or copper filings put into the cells i.e., dropped into the acid, will greatly shorten its life. Copper coins or a few pieces of iron will accomplish the same and more slowly. One hundred to 150 cubic centimeters of vinegar in each cell greatly reduces the life of the battery, but the odor of the vinegar may reveal what has happened.
(g) Gears
(1) Remove the lubricant from or put too light a lubricant in the transmission and other gears.
(2) In trucks, tractors, and other machines with heavy gears, fix the gear case insecurely, putting bolts in only half the bolt holes. The gears will be badly jolted in use and will soon need repairs.
(h) Tires
(1) Slash or puncture tires of unguarded vehicles. Put a nail inside a match box or other small box, and set it vertically in front of the back tire of a stationary car; when the car starts off, the nail will go neatly through the tire.
(2) It is easy to damage a tire in a tire repair shop: In fixing flats, spill glass, benzine, caustic soda, or other material inside the casing which will puncture or corrode the tube. If you put a gummy substance inside the tube, the next flat will stick the tube to the casing and make
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