Why are steno vowels on the thumbs

Quick question for the history buffs: I tell week-one students that thumbs-on-vowels promotes alternating hands and steadier syllable timing, and in a 5-minute drill last Friday they averaged +9 WPM with that cue. Does anyone know the original design rationale from the early stenotype makers, or have a solid source that documents it?

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I’ve always heard it goes back to Ireland’s early Stenotype: thumbs on vowels to split the labor and force cross-hand timing. > Friday they averaged +9 WPM with that cue. Does anyone know the original Agree on the timing part — that’s exactly what the designers leaned into, plus it cuts finger travel. For a concrete step, run a 2-minute metronome drill at 84 BPM with thumbed vowels on the beat and consonants off-beat, then swap. If you need a cite, the Ireland-era rationale is summarized here: Stenotype - Wikipedia, but , I still haven’t found a single line-quote from the Universal Stenotype manual; does anyone have a sca.

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