French Optical Telegraphy, 1793-1855 : Hardware, Software, Administration

French optical telegraph represented a highly refined blend of software and hardware generating performance levels in long distance communication which were, given the limitations of the hardware, quite remarkable. Had the electromagnetic telegraph not become available, French optical telegraphy, or a variant, would have served increasingly as an imperfect substitute, particularly in the transmission of price data on commodity, stock, and bond exchanges. This affirmation of the commercial viability of optical telegraphy does not, however, significantly reduce our estimate of the contribution of electromagnetic telegraphy to economic growth. The more substantial economic payoff to the electromagnetic device came from its use by firms to reduce inventory holdings and raise fixed capital utilization rates in sectors with large minimum efficient scales. Here optical telegraphy's vulnerability to disruption by the weather, limited channel capacity, and restriction to daylight use would have made it a very imperfect substitute in an age of rail speed communication