Convertible -- when was it first used in automotive literature?

Note the ad taken from the January 14, 1914 The Horseless Age. Clearly the term convertible is used. Then note my discussion on closed and open cars and the use of the word convertible as mentioned in a note to my 2nd edition of The Automobile file and American Life. One must conclude that the label convertible goes back long before 1921. My hunch is that a good bit of automotive history is nothing more than well-worn passed along stories from one generation to another. We need to throughly exhume the past and rescue it from complacent historians, including myself!

---

For the car to be an extension of the home, it had to be closed rather than open, unlike the pre-WWI roadster or touring car. Thus, the first and undoubtedly most important step in creating personal space in the automobile was the closed steel body. Historian James J. Flink has called this development “the single most significant automotive innovation.”⁴²Almost immediately after World War I, public demand increased dramatically for a closed car that would no longer be a seasonal pleasure vehicle, but rather all-weather transportation. The few closed body cars built before WWI were extremely expensive and the work of custom coach builders. This rise in demand during the 1920s, coupled with a remarkable number of concurrent technical innovations in plate glass and steel manufacture, resulted in a revolution in production methods, productivity, and economies of scale. William J. Abernathy [PJB1] has carefully characterized the transformation that took place on the shop floor and assembly line, the first fruits of which occurred when in 1921 Hudson first mass-produced a closed car. The transition away from rag tops (the word convertible was first used in 1927 and officially added to the Society of Automotive Engineers lexicon in 1928) was rapid and contributed to a venerable prodigy of production by the end of the 1920s, as depicted in Table 4.⁴³

43. Gunnell’s assertion that the word convertible was first used in 1927 is not true. In 1923 Nordyke & Marmon Company published a brochure entitled “Shall I buy an Open Car, or a Closed Car”? A Practical answer to this Question. (Brochure is in author’s collection). In it the claim is made “To give you a closed car now, an open car next spring, and a fine motor car the year ‘round all at the price of an open car, there is the Marmon Convertible Phaethon. It is a fine family car for thrifty people who are looking ahead. It is literally both a closed car and an open."