subways_largeFor the pedantic rail enthusiasts, the definition of a subway used here is, with some caveats, “a network containing high capacity grade-separated passenger rail transit lines which run frequently, serve an urban core, and are underground or elevated for at least part of their downtown route.” For the rest of you, the definition is “an underground train in a city.” (source:

Exploring interesting representations of space:


San Francisco after the great fire following the 1906 earthquake. George Lawrence’s panorama camera produced a mammoth negative of 18 x 48 inches and was raised 2,OOO feet over the bay by his “Captive Airship”.


A diagrammatic representation of the “Captive Airship” being flown from a ship. The parts indicated are as follows: s, spreader rod to keep kite clear of the main line; g, the long booms extending 15 feet out from the base of the camera cradle; h, small lead weights of several ounces at the end of each boom; i, 120-foot long silk cords; j, the three-pound lead weight; o and p, a line and pulley to keep j from dragging in the water on launch and retrieval; and r, the winch.

Diagrams and details after the report by Lieutenant L. H. Chandler, U.S. National Archives.