n the 1850s, two men named George S. Lawrence and Thomas Houseworth left the California gold mines to open a shop in San Francisco. Their optical shop sold a number of goods, like mathematical instruments, cutlery, billiard balls and chalk. In 1859, they added to their store in a monumental and historic way. They started buying stereographs.Stereographs were the early View-Masters. Two photos were mounted side-by-side so that when viewed together through a stereoscope, they appeared to be a three-dimensional image. Much like View-Master slides, exotic locations and pretty vistas were the most desirable, often purchased to remind travelers of their vacations. Collecting stereographs was a popular hobby for middle class Americans — one that Lawrence and Houseworth capitalized on.The duo began contacting local photographers in the 1860s and soon built up a collection of hundreds of California images. Their stereographs numbered over 1,000 and were published in a series of catalogs called ‘Gems of California Scenery’. You can see 36 of their images of mid-1860s San Francisco in the gallery above.Lawrence and Houseworth’s stereograph collection was acquired by the Library of Congress in 1867 and has been digitized for viewing online.