[GreenKeys] 28 stock ticker?

[Jim Haynes]

On Tue, 30 Jul 2019, Jeffrey Angus wrote:

> Speaking of stock tickers, what was the one under a glass dome?
>
There are several different stock tickers that were enclosed in glass
bell jars.  You might google for Edison stock ticker to get an entry
to the matter.  They all depended on a type wheel that stepped around
until the desired character was under the print hammer.  One of the
problems was keeping the type wheels synchronized with the sending
machine.  This was solved by adding a mechanism which caused the wheel
to hit a stop after several revolutions; thereafter it would be in sync
with the sending machine.  There were also machines that required winding
a spring or setting weights to power the wheel.  The late tickers
propelled the wheel by current reversals sent over the wire, working a
stair-step sort of escapement attached to the wheel.  Google for self
winding ticker.