AHSS*2190 Lecture Notes - Lecture 4: Automatic Transmission, Claude Chappe, Semaphore Line
Week 4: Electricity and Media
Optical Telegraph
-Developed in late 18th century by Claude
Chappe
-Complex system of coded messages delivered
from a series of high towers
-Cuts time for delivery of messages dramatically
-Very labour intensive
-Could only work during daylight and on clear
days
Electric Telegraph
-Invented by Morse in 1837
-Uses electricity to carry messages over metal wires
-Capacity for carrying messages increases compared to optical telegraph
-First science based invention
-Growth is remarkable, particularly in last half of 19th century
-In Europe, initial use is for administrative and military applications
-Britain sees private investment with telegraph lines set up alongside railway lines
-American industry promoted by business interests
-Canada’s development lags compared to U.S.
What is Needed?
(1) Human operator to manually press the dots and dashes
(2) Encoding device
(3) Physical wire line to transmit electric impluses
(4) Another human operator to receive and decode messages at the other end
(5) Delivery person – “telegraph boy”
Electric Telegraph
-Instant Communication
➔Telegrams are expensive to send; Must be brief, charged by word; Opens
up real-time information to railways, stockbrokers
-Separates Transportation and Communication
➔Before telegraph, local markets were independent of each other
➔What is Arbitrage?
➔We own commodities without taking physically acquiring them;
Standardization of commodities
➔What is spatialization?
-Limitations
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Document Summary
Developed in late 18th century by claude. Complex system of coded messages delivered from a series of high towers. Cuts time for delivery of messages dramatically. Could only work during daylight and on clear days. Uses electricity to carry messages over metal wires. Capacity for carrying messages increases compared to optical telegraph. Growth is remarkable, particularly in last half of 19th century. Britain sees private investment with telegraph lines set up alongside railway lines. In europe, initial use is for administrative and military applications. Telegrams are expensive to send; must be brief, charged by word; opens up real-time information to railways, stockbrokers. Before telegraph, local markets were independent of each other. We own commodities without taking physically acquiring them; Initially, only one message could be sent at a time. Rate of sending-receiving was slow, approximately 60 characters per minute. Wires connected to only a few buildings such as telegraph offices, newspapers, government etc.
