Safety cut rope axe man In the first nuclear reactor, constructed by Enrico Fermi in 1942 under the bleachers of the University of Chicago football stadium, the control rods were held up by a manila rope. A man with an axe was told to cut the rope if the reactor got out of hand. This "safety cut rope axe man" is supposedly the origin of the term SCRAM for an emergency shutdown procedure. Brian Hayes, Infrastructure: A Guide to the Industrial Landscape wordsacronymsenergy
City districts Districts have to help bring the resources of a city down to where they are needed by street neighborhoods, and they have to help translate the experiences of real life, in street neighborhoods, into policies and purposes of their city as a whole. And they have to help maintain an area that is usable, in a civilized way, not only for its own residents but for other users—workers, customers, visitors—from the city as a whole. To accomplish these functions, an effective district has to be large enough to count as a force in the life of the city as a whole. The “ideal” neighborhood of planning theory is useless for such a role. A district has to be big and powerful enough to fight city hall. Nothing less is to any purpose. Jane Jacobs, The Death and Life of Great American Cities Paths, edges, districts, nodes, landmarks