What you pictured aren't necessarily balloon stacks.

What you pictured on 169 is more usually called a diamond smokestack. Historically that model contained the spark arresting cone and netting for coal-burning locomotives prior to the adoption of extended smokeboxes which contained the spark arresting equipment instead. That being said, the World's Fair and modern display items on 169 might well be dummy stacks placed just for show. As newly-built, some of the class 47 locomotives had diamond stacks, and others had extended smokeboxes with straight stacks (apparently the D&RG was experimenting during the 1880's). Later on, with the development (around 1900ish) and adoption of the master mechanic front end, the diamond stacks fell entirely by the wayside.

Balloon stacks--a generic term for several types of spark-arresting smokestack--typically have a much larger appearance and are more normally associated with wood burning, although some variants were for coal fuel as well. This generic term can include civil war-era bonnet stacks, radley & hunter stacks, stevens stacks, the South Park's nesmith stacks, and others of similarly large bulbous shape (they broadly resemble hot air balloons, hence the nickname). Note that these smokestacks can have quite different internal arrangements, but in most cases the lower portion of the funnel serves as a spark/cinder hopper, hence why it's so large. The holes for emptying the hopper are usually (but not always) visible in the lower sides near the base of such smokestacks. Technically these large spark arrestors in most cases fit over the smaller, actual smokestack but that mechanical distinction is largely unnecessary in normal discussion.