M-W has 1920 andd OED has 1922. Using Newspaperarchive, 31 July, 1910 Colorado Springs Gazette 6/4 >>Over the spring(a natural carbonic acid one--ed), Mr. Heistand proceeded to build a real up-to-date soda fountain, with all the nickled appliances so dear to the heart of the drug store "soda-jerk."<< Sam Clements