LOS ANGELES — “A machine that makes the land pay.” That’s how architect and Manhattanite Cass Gilbert defined skyscraper in 1900, when the building type was — ahem — just getting off the ground. But ...

Photographic slides were popular in the middle part of the 20th century, but are long forgotten now. If you’ve found a handful in a dusty attic, you might consider sending them away to be digitized ...