Today, I found an interesting photograph of a solar eclipse attributed to Ansel Adams. You can find this image at http://ccp.uair.arizona.edu/item/9820. This photograph is labelled with possible dates from 1923 to 1925 and is said to have been photographed from a place called Cantonville, California.
There are two issues with this identification:
- The only central solar eclipse in this time span that visited California was the 1923 total solar eclipse which grazed the southwestern coast. But the photograph clearly shows what is known as a 'broken annular' eclipse in which the Moon very nearly occults the Sun but a string of Baily's Beads persists around the circumference.
- There is no identifiable place in California called Cantonville.
The photograph could not have been of the 1923 eclipse and Cantonville does not seem to exist. So where and when was this photograph taken? I posed this question to the Solar Eclipse Mailing List (SEML) and quickly received a plausible solution.
First, the eclipse is most probably the annular-total (hybrid) solar eclipse of April 28, 1930. The total phase of this eclipse was calculated to be exceedingly short, about 1 second. With totality this short, it is likely that the Sun's disk was never completely extinguished. That is, some bits of the Sun's photosphere were left uncovered by some of the lunar valleys in profile.
Second, the place name of 'Cantonville' is very probably a misspelling of Camptonville where an eclipse observing expedition was dispatched by the Lick Observatory that year.
This video offers some confirmation of this. You will see that the skies were characterized by thin clouds and that the bead pattern in the video resembles the bead pattern in the photograph. The evidence of the similar bead pattern and the close resemblance of the place names 'Cantonville' and 'Camptonville' suggests strongly that this is the eclipse and the location of Ansel Adams' photograph.
Steve Allen of the Lick Observatory noted in a communication on SEML that perhaps Ansel Adams did not actually take this photograph, but made a photographic print from a plate from the Lick Observatory archive. He notes that Ansel Adams did some photographs of the Lick Observatory and it is plausible that he had access to the eclipse archive.
Update on August 29: In a subsequent email communication to SEML, Steve Allen notes that Ansel Adams was a neighbor of the brother of an astronomer on the expedition and opines that it is plausible that Ansel Adams took the plate as well as made the print. At present, there is no conclusive evidence of whether Adams or a Lick Observatory astronomer took the plate.
A further confirmation of the identity of the eclipse photographed by Ansel Adams is this simulation of the Baily's Beads computed for this time and place by Xavier Jubier, xjubier.free.fr. This is from his software app Solar Eclipse Maestro. The match is very good and there is no doubt that the correct eclipse has been identified.
Update on September 8: I've made an inquiry to the Center for Creative Photography which holds this photograph. I asked for further evidence which can ascertain whether Ansel Adams took the photographic plate as well as making the print. I've received this reply from Leslie Squyres:
Dear Michael Zeiler,
Attached to this email are images of the verso of the photograph by Ansel Adams. I contacted a scholar who worked closely with Adams. Andrea Stillman wrote, “It's by Ansel. As I recall he was very proud of it.” I sent the verso images to her to verify the handwriting for me. I know for certain that the date correction is Ansel Adams’s handwriting. She remembers that somewhere Adams talks about making the photograph – I’m still trying to track down that reference and will get back to you. In a 1978 interview for the Bancroft Library Oral History project, Adams mentions that his father was treasurer of the Astronomical Society of the Pacific and that he and his father went to “Mt. Hamilton often.”
Adams was notoriously bad at recording dates. If you know for absolute certainty that the photograph was taken in 1930, could you let me know?
Director of the Volkerding Center for Research & Academic Programs
Center for Creative Photography, University of Arizona
No definitive answer yet on whether Ansel Adams indeed took the plate, but Leslie's message reveals new clues and some further leads.
Below are details of the reverse side of the print.