If you notice the bottom right, it says "Beach Midway... 1934". The Sky Ride was built in 1933, and it wasn't really on the Midway. The Midway was on the mainland south of it in 1933.
The 1934 Beach Midway was just south of Adler Planetarium, and replaced the Jantzen (a swimsuit company), bathing beach that was there in 1933.
The steel coaster "Ride of the Century" was never built.