(4) Jam paper, bits of wood, hairpins, and anything else that will fit, into the locks of all unguarded entrances to public buildings. (2) _Industrial Production: Manufacturing_ (a) Tools (1) Let cutting tools grow dull. They will be inefficient, will slow down production, and may damage the materials and parts you use them on. (2) Leave saws slightly twisted when you are not using them. After a while, they will break when used. (3) Using a very rapid stroke will wear out a file before its time. So will dragging a file in slow strokes under heavy pressure. Exert pressure on the backward stroke as well as the forward stroke. (4) Clean files by knocking them against the vise or the workpiece; they are easily broken this way. (5) Bits and drills will snap under heavy pressure. (6) You can put a press punch out of order by putting in it more material than it is adjusted for—two blanks instead of one, for example. (7) Power-driven tools like pneumatic drills, riveters, and so on, are never efficient when dirty. Lubrication points and electric contacts can easily be fouled by normal accumulations of dirt or the insertion of foreign matter. (b) Oil and lubrication systems are not only vulnerable to easy sabotage, but are critical in every machine with moving parts. Sabotage of oil and lubrication will slow production or stop work entirely at strategic points in industrial processes. (1) Put metal dust or filings, fine sand, ground glass, emery dust (get it by pounding up an emery knife sharpener) and similar hard, gritty substances directly into lubrication systems. They will scour smooth surfaces, ruining pistons, cylinder walls, shafts, and bearings. They will overheat and stop motors which will need overhauling, new parts, and extensive repairs. Such materials, if they are used, should be introduced into lubrication systems past any filters which otherwise would strain them out. (2) You can cause wear on any machine by uncovering a filter system, poking a pencil or any other sharp object through the filter mesh, then covering it up again. Or, if you can dispose of it quickly, simply remove the filter. (3) If you cannot get at the lubrication system or filter directly, you may be able to lessen the effectiveness of oil by diluting it in storage. In this case, almost any liquid will do which will thin the oil. A small amount of sulphuric acid, varnish, water-glass, or linseed oil will be especially effective. (4) Using a thin oil where a heavy oil is prescribed will break down a machine or heat up a moving shaft so that it will “freeze” and stop. (5) Put any clogging substance into lubrication systems or, if it will float, into stored oil. Twisted combings of human hair, pieces of string, dead insects, and many other common objects will be effective in stopping or hindering the flow of oil through feed lines and filters.