The fountain is right outside my office building. I always thought it's related to Benjamin Franklin. But upon closer inspection, it is the Cogswell Temperance Fountain. Here's what I found about the fountain.
"Henry D. Cogswell was an eccentric dentist from San Francisco who made a fortune from real estate and mining stocks. He wanted to be remembered forever. He also believed Americans were drinking too much alcohol. So, he paid for the building of a number of water fountains like this all over the United States. "
"Cogswell himself designed each fountain and each is unique. Atop the DC fountain is a water crane; in the center are two entwined dolphins."
"The Cogswell Fountain in DC no longer has water, although there is a city water fountain located a few feet away. Given the notoriously poor quality of DC's water, one wonders whether Cogswell's scheme to get Washingtonians to drink water for their health is such a great idea."
"NOTE: For many years, DC had a Cogswell Society. The master of ceremonies at their dinner was known as the "lead Crane". He would offer a toast to Temperance; the proper response (with drink in hand) was "I'll drink to that!""