|Note_en=Confirmed by finding the same AD on the September 1921 number of ''Popular Science''. Advertising for a [[Waterman 1x]] eyedropper model, describing the different filling systems, and citing the [[pump filler]] between the self-filling types, along with [[lever filler]] | |Note_en=Confirmed by finding the same AD on the September 1921 number of ''Popular Science''. Advertising for a [[Waterman 1x]] eyedropper model, describing the different filling systems, and citing the [[pump filler]] between the self-filling types, along with [[lever filler]] |