[ 3'3 ] 



SUPPLEMENT to Mr. EDGEWORTH's ESSAY 

 upon the TELEGRAPH. 



1^ I N C E the Royal Irifh Academy did me the honour to Read Dec. 5^ 



• 796. 

 accept of my eflay on the telegraph, I have made material im- 

 provements in its conIlrud;ion, which I think it my duty to-, 

 communicate. 



In September 1796, the Lord Lieutenant ordered me to pre* 

 pare telegraphs for an experiment before his Excellency. In 

 confequence I conftrudted four new telegraphs — I had found 

 that the large machines thirty feet high, with which my fons 

 talked in September 1794 acrofs the channel, between Ireland 

 and Scotland, were liable to accidents in flormy weather : my 

 firft confideration therefore was to contrive fome means of fur- 

 ling their canvas when they were not in ufe ; and from the 

 rigging of fhips it was obvious that cordage was for this pur- 

 pofe preferable to inflexible braces of wood. I therefore adopted 

 the following conftrudion : 



Vol. VL R r A. (fig. 4.) 



