Introduction to Permaculture A Book by Bill Mollison modernfarmer.com The conscious design and maintenance of agriculturally productive systems which have the diversity, stability, and resilience of natural ecosystems. It is the harmonious integration of the landscape with people providing their food, energy, shelter and other material and non-material needs in a sustainable way. About PermaculturePermaculture ethicsUsing akido on the landscapePermaculture principlesDesign is a connection between things+25 More 172. Garden Growing WildProtected, yet tuned inHints towards a non-extractive economy farmingnatureecosystemssustainabilityagriculture
Materials and how to employ them Forming a paper clip presents a common dilemma encountered by engineers and inventors: the very properties of the material that make it possible to be shaped into a useful object also limit its use. If one were to try and make a paper clip out of wire that stayed bent too easily, it would have little spring and not hold papers very tightly. On the other hand, if one were to use wire that did not stay bent, then the clip could not even be formed. Thus, understanding the fundamental behavior of materials and how to employ them to advantage is often a principle reason that something as seemingly simple as a paper clip cannot be developed sooner than it is. Henry Petroski, The Evolution of Useful Things Ideas behind their time material