Former student and school volunteer John Weidinger, researching the school's history, found out about it in an old newspaper.
"I did find the one sentence in the San Francisco Call that said the mayor placed a copper box in the wall," he said.
Students, former students and former teachers watched as the box was open. Among the things found was a booklet that included salaries -- an elementary school teacher made $2,460 a year. Then there were letters, one with pictures and a letter from an improvement club that saw a great future for the neighborhood.
"The city of San Francisco has just about recovered from the effects of the great earthquake and fire of 1906 and is now on a fairway to greater prosperity than ever," Hydra Mendoza from the Mayor's Office said.
The letter also wonders if anyone will ever read this.
"I'm going to take the time to see if I can read those documents completely," Weidinger said.
Weidinger plans to write an article.
The school opened in September of 1911 so there will be a centennial celebration in the fall and they will install another time capsule to share with future generations. The question is what to put in it.
"We really wanted to see the contents of what's in there now and that will help us decide what goes in there," school principal Kristin Tabernetti said.
The next time capsule will be opened in 2111.