The Chappe telegraph supported 98 possible signals with 6 of those being reserved for service purposes (like signalling end of message), so 92 possible message signals. If you could get that to 96 then you could transmit ASCII characters using one signal from Decimal 32 to Decimal 126, and use one signal to enter the original "two signals per symbol" mode for the rest of ASCII and other symbols. Then automate it with machine vision and we'll have an 1800's style steampunk Internet.