(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 it unusable. Or, when you fix a flat tire, you can simply leave between the tube and the casing the object which caused the flat in the first place. (3) In assembling a tire after repair, pump the tube up as fast as you can. Instead of filling out smoothly, it may crease, in which case it will wear out quickly. Or, as you put a tire together, see if you can pinch the tube between the rim of the tire and the rim of the wheel, so that a blow-out will result. (4) In putting air into tires, see that they are kept below normal pressure, so that more than an ordinary amount of wear will result. In filling tires on double wheels, inflate the inner tire to a much higher pressure than the outer one; both will wear out more quickly this way. Badly aligned wheels also wear tires out quickly; you can leave wheels out of alignment when they come in for adjustment, or you can spring them out of true with a strong kick, or by driving the car slowly and diagonally into a curb. (5) If you have access to stocks of tires, you can rot them by spilling oil, gasoline, caustic acid, or benzine on them. Synthetic rubber, however, is less susceptible to these chemicals. (8) _Transportation: Water_ (a) Navigation (1) Barge and river boat personnel should spread false rumors about the navigability and conditions of the waterways they travel. Tell other barge and boat captains to follow channels that will take extra time, or cause them to make canal detours. (2) Barge and river boat captains should navigate with exceeding caution near locks and bridges, to waste their time and to waste the time of other craft which may have to wait on them. If you don’t pump the bilges of ships and barges often enough, they will be slower and harder to navigate. Barges “accidentally” run aground are an efficient time waster too. (3) Attendants on swing, draw, or bascule bridges can delay traffic over the bridge or in the waterway underneath by being slow. Boat captains can leave unattended draw bridges open in order to hold up road traffic. (4) Add or subtract compensating magnets to the compass on cargo ships. Demagnetize the compass or maladjust it by concealing a large bar of steel or iron near to it. (b) Cargo (1) While loading or unloading, handle cargo carelessly in order to cause damage. Arrange the cargo so that the weakest and lightest crates and boxes will be at the bottom of the hold, while the heaviest ones are on top of them. Put hatch covers and tarpaulins on sloppily, so that rain and deck wash will injure the cargo. Tie float valves open so that storage tanks will overflow on perishable goods. (9) _Communications_ (a) Telephone