The Knowledge: How to Rebuild Our World From Scratch by Lewis Dartnell Read Free Book Online

in an urban environment. Populated areas are packed with combustible materials, from furniture and wooden fittings to garden shrubs, that can be thrown on a fire for heat and cooking.
    The issue is not starting a fire or keeping it going, but where to make it. The vast majority of recently built houses and apartments have no working fireplace. If need be, you can safely contain a fire within a metal trash can or bring a barbecue indoors, or if the apartment has a concrete floor, you could rip away a patch of carpet and light a fire directly on the concrete. You’ll need to allow the smoke and fumes to escape through a slightly opened window (especially if you’re forced to resort to combusting synthetic fabrics or furniture foam). But your best bet would be to try to find an older cottage or farmhouse that is appropriately equipped to be heated by fires rather than radiators—this is one of the major incentives to abandon the cities as quickly as possible after the Fall, as we’ll see in a bit.

WATER
    After shelter and protection from the elements, the second priority on your list is to secure clean drinking water. Before the municipal water supply runs dry you should fill your bathtub and sinks to the brim with water, as well as any clean buckets or even strong polyethylene trash bags. These emergency water stores should be covered to keep them free from detritus and to block the light that allows algal growth. Bottled water can be scavenged from supermarkets and from water coolers in office buildings. Other reservoirs of water you’ll be able to drain include hotel and gym swimming pools, as well as the hot water tanks in any large building. In time, you’ll come to rely on water sources you’d normally have wrinkled your nose at. Every survivor will need at least three liters of clean water every day, and more in hot climates or with exertion. And keep in mind that this is for rehydration alone, and does not include water necessary for cooking and washing.
    Water that doesn’t come from a sealed bottle must be purified. A surefire method for sterilizing water of pathogens is to bring it to a hearty boil for a few minutes (although this offers no protection against chemical contamination). This is very time-consuming, however, and will rapidly eat through stocks of fuel. A more practical, longer-term solution for purifying larger volumes of water, once you have settled down after the Event, relies on a combination of filtration and disinfection. A rudimentary but perfectly adequate system for filtering out particles in murky lake or river water uses a tall receptacle such as a plastic bucket, a steel drum, or even a well-cleaned trash can. Punch some small holes in the bottom, and cover with a layer of charcoal, either taken from a hardware store or created yourself using the instructions here . Alternate layers of fine sand and gravel on top of the charcoal. Pour the water into your receptacle, and as it drains through, it will be effectively filtered of most particulate matter.
    The first option for disinfecting this filtered water to eliminate waterborne pathogens is to use dedicated water-purification treatments, such as iodine tablets or crystals available from camping stores. If you can’t find any, there are some surprising alternatives that will also work perfectly well, such as chlorine-based bleaches formulated for household cleaning. Just a few drops of a 5 percent liquid bleach solution that has sodium hypochlorite listed as the main active ingredient will disinfect a whole liter of water in an hour. But carefully check the label to ensure that the product doesn’t also contain additives such as perfumes or colorants that may be poisonous. Several fluid ounces of bleach found under a kitchen sink can purify around 500 gallons of water—almost two years’ supply for one person.
    Products used for chlorinating swimming pools, scavenged from the storeroom of a gym or wholesaler, can also be used at a