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History in Motion

Solving History Mysteries at the SFMTA Photo Archive

Thursday, July 11, 2019

hand holding negative above light table with envelopes in background
An archivist examines a 100-year-old photographic negative. This type of negative was shot on plate glass coated with light-sensitive materials, a common format in the late 1800s and early 1900s.

Sometimes historic photographs are self-explanatory— past famous people and events are easily recognized or researched— but even in a professional photography setting like the SFMTA Photo Dept. and Archives there are mysteries that need to be solved. Many of the thousands of images dating to 1903 were taken in unidentified San Francisco locations and photographed for reasons that have been lost to time. Through the course of their work, the SFMTA Photo staff has developed deductive skills to crack the case based on clues in an image and other primary source materials.

streetcar on street with houses in background
A photograph from the SFMTA Photo Archive collection taken in March 1915 on Coleridge Street and Virginia Avenue.

Here's an example of a photo that required more research than most to decipher the exact location based on clues gathered during the archiving process. The first clues is the label on the negative itself, visible in the lower right corner of the scanned image above. This label was applied by the original photographer and shows a series of numbers that provide valuable information to archivists looking to properly locate and describe the image.

On the far right is a set of numbers that many amateur detectives could deduce: the series “3-23-15” indicates a date of March 23, 1915. The other two codes on the label are a bit more obscure. On the left is the number “4815,” and in the middle “A.R. 2189.” When an SFMTA Photo archivist looks at this label, they know that the number “4815” is an identification number assigned by the original photographer and that “A.R. 2189” indicates the photograph was taken to for an accident report, number 2189.

With the negative ID number in hand, archivists can cross-reference that number with the photographer’s original notebook. This particular photograph comes from the United Railroads photographer John Henry Mentz, who kept consistent records of the thousands of photos taken over the course of his forty-year career. As seen below, Mentz’s notes or this photo (#4815) say “Mission + 24thSt Car 1314 A.R. 2189.”

scan of book page with hand written entries
The original logbook notes documenting image 4815, written by photographer John Mentz in March 1915.

At this point some might assume the location is Mission & 24th St. and say, “ah ha, mystery solved!” But sharp-eyed San Franciscans will notice that Mission and 24th is an unlikely location for this photo. Even as far back as 1915, Mission was a bustling corridor and this image was clearly taken on a much quieter, narrow, residential street.

The final clue lies in the number “11” signed on the streetcar. SFMTA Photo staff read this to mean the streetcar was from the “11 Mission 24thStreet” streetcar line, which ran out of the 29th & Mission Street Car House. Located on Mission near Virginia Ave, the car house had a rear entrance on Coleridge Street, a quite residential block that matches the setting seen here. Additionally, archivists can cross reference this shot to other images in the collection that list the car house as a location and see whether or not the buildings and street details seen here match the other images.

With these various details, the location and significance of the photo have been identified and the digital version of the image can be cataloged with searchable keywords and shared online.

To see the full SFMTA Photo Archive collection from 1903 to 1978, check out the historic photo collections at the SFMTA Photo website. Daily doses of historic San Francisco #fromthearchive are also delivered on our Instagram @sfmtaphoto.