A CENTURY OF THE TELEGRAPH IN FRANCE. 791 



evidence against the submergence is now almost, if not quite, con- 

 clusive. 



In the brief outline now given of the facts of glacial geology- 

 bearing upon the former existence, the thickness, extent, and mo- 

 tion of ice-sheets, it has only been possible to treat the subject 

 very broadly, omitting all those details and minor difficulties 

 which can not be discussed within the limits of a popular article. 

 My object has been to explain the nature and amount of the con- 

 verging evidence demonstrating the existence of enormous ice- 

 sheets in the Northern hemisphere, to serve as a basis for the dis- 

 cussion of the glacial origin of lake-basins, which will form the 

 subject of another article. Fortnightly Revieiu. 



A CENTURY OF THE TELEGRAPH IN FRANCE. 



By WALTER LODIAN. 



IT is one hundred years ago (the 22d of March, 1793) since a 

 young man named Claude Chappe presented himself at the 

 bar of the Legislative Assembly. He carried there a secret vocabu- 

 lary composed of nine thousand nine hundred and ninety-nine 

 words, represented by some numbers, and destined to be trans- 

 mitted by a system of visual telegraphy by means of a machine 

 carrying the signals from station to station. 



The examination of the machine was promptly confided to a 

 committee, which reported in favor of its adoption, and a little 

 after, the Convention voted the funds necessary to the establish- 

 ment of a trial line. 



It is this memorable event the origin of the most marvelous 

 discovery of our times which the telegraphic people have re- 

 cently feted as solemnly as possible. 



On this occasion it has appeared to us useful as well as interest- 

 ing to retrace the history of telegraphy in France, to note briefly 

 the successive stages and the perfecting of the telegraphs which 

 have transformed the world. 



Some essays in telegraphy were made in modern times, notably 

 at the end of the seventeenth century, by Dr. Hooke, an English 

 physician, who made service of an apparatus consisting of some 

 characters of a sufficient size for being perceived at a distance, 

 each one corresponding to a letter of the alphabet. 



Under the reign of the fourteenth Bourbon clique, a savant 

 (G. Amontons), who became later on member of the Academy of 

 Sciences, took up the study of the problem of aerial telegraphy. 

 Highly interesting was the result thereof. Fontenelle, the litera- 



