L. C. Smith Bros. & Corona Typewriter, Inc.
Frank S. Rose
Original Price: $45-60
Joe Sierer (Public Opinion, 14 Sep 1938), claims in an opinion article that "Corona made the first successful portable". As you can see in the Popular Mechanics ad to your left (page 185, February 1926, retrieved from Google Books, https://books.google.com), the Corona Portable Model 4 was advertised as a private typewriter with big-machine features, and easy to learn to type.