For more information about Claude Chappe and the invention of telegraphy, follow these links:

http://people.deas.harvard.edu/~jones/cscie129/images/history/chappe.html
http://www.geocities.com/Hollywood/Boulevard/5485/tele2.htm
http://micro.magnet.fsu.edu/optics/timeline/people/chappe.html
http://www.malexism.com/medias/semaphore.html
http://www-ic2.univ-lemans.fr/chappe/famille.html
http://www.amazon.com/exec/obidos/ASIN/0425171698/qid=1093909999/sr=ka-1/ref=pd_ka_1/102-7942337-1392915
http://chappe.ec-lyon.fr/

For more information about Samuel Morse and William Cooke, follow these links:

http://www.morsehistoricsite.org/history/morse.html
http://lcweb2.loc.gov/ammem/atthtml/mrshome.html
http://www.rod.beavon.clara.net/samuel.htm
http://chem.ch.huji.ac.il/~eugeniik/history/cooke.html
http://www.cwhistory.com/history/html/CWheatStn.html