\, -87degree distinguishable. ‘ And it is necessary to pursue that distinction. We should notice also that while most industries are ultimately convertible or applicable to the prosecution of war, it is possible to distinguish between industries in the degree of their immediate indispensability for war purposes, TFinally, while industries attract population and vice versa, modern means of transportation make possible a locational flexibility between an industry and those people who service it and whom it serves. Thus it would seem that the first step-in reducing our national vulnerability is to catalog the industries especially and immediately necessary to atomic bomb warfare—-a relatively small proportion of the total-~and to move them out of our cities entirely. Where those industries utilize massive plants, those plants should as far as possible be broken up into smaller units. Involved in such a movement would be the labor forces which directly service those industries, The great mass of remaining industries can be left wherethey-are within the cities, but the population which remains with them can be encouraged, through the further development of suburban building, to spread over a greater amount of space. Thole areas deserving to be condemnned in any case could be converted into public parks or even airfields. The important element in reducing casualties is after all nov the shape of the individual city but the spatial density of population within it, Furthermore, the systems providing essential services, such as those supply- ing or distributing food, fuel, water, communications, and medical care, could and should be rearranged geographically. Medical services, for example, tend to be concentrated not merely within cities but in particular sections of those cities. The conception which might govern the relocation of services within the cities is that which has long been familiar in warship design——-compartmentation, And obviously where essential services for larce rural areas are wimecessarily concentrated in cities, they should be moved out of them, tains especially to communications, That situation per-