Vincent Joseph Schaefer (July 4, 1906 – July 25, 1993) was an American chemist and meteorologist who developed cloud seeding. On November 13, 1946, while a researcher at the General Electric Research Laboratory, Schaefer modified clouds in the Berkshire Mountains by seeding them with dry ice. While he was self-taught and never completed high school, he was issued 14 patents.

In 1943, the focus of Schaefer's and Langmuir's research shifted to precipitation static, aircraft icing, ice nuclei, and cloud physics, and many of their experiments were carried out at Mount Washington Observatory in New Hampshire. In the summer of 1946 Schaefer found his experimental "cold box" too warm for some laboratory tests he wanted to perform. Determined to get on with his work, he located some "dry ice" (solid CO2) and placed it into the bottom of the "cold box."

Creating a cloud with his breath he observed a sudden and heretofore unseen bluish haze that suddenly turned into millions of microscopic ice crystals that dazzled him in the strobe lit chamber. He had stumbled onto the very principle that was hidden in all previous experiments—the stimulating effect of a sudden change in heat/cold, humidity, in supercooled water spontaneously producing billions of ice nuclei. Through scores of repeated experiments he quickly developed a method to "seed" supercooled clouds with dry ice.

In November 1946 Schaefer conducted a successful field test seeding a natural cloud by airplane—with dramatic ice and snow effect. The resulting publicity brought an abundance of new correspondence, this time from people and businesses making requests for snow and water as well as scientists around the world also working on weather modification to change local weather conditions for the better. Schaefer's discovery also led to debates over the appropriateness of tampering with nature through cloud seeding.

According to wikipedia