I have an actual copy of this issue of Liberty - somewhere. Article was written in, I think, 1928, so it's pre-Stooge, and talks more about Adler's career as a circus clown (he was the most famous clown of his era) but does touch on his work writing for Sennett. Within a year he'd be writing for Harold Lloyd and other big name comedians later in the 30s (Laurel and Hardy et al).