WITH NOTES. 399 



6. 



How at a Window, far as Eye 

 can difcover 2 black from white, a 

 man may hold difcourfe with his 

 Correfpondent, without noife made 

 or notice 8 taken ; being, according 

 to occafion given and means afford 

 ed, Ex re nata, and no need of Pro- 

 vifion before-hand ; though much 

 better if forefeen, and means pre 

 pared for it, and a premeditated 

 courfe taken by mutual confent of 

 parties. 



2 discern. 3 noise for, notice. P. 



7- 



A way to do it by night as well 

 as by day, though as dark as Pitch 

 is black. 



\A mute and perfect discourse by colours.~\ 

 [To hold the same by night J] 



These two may be ranked as the same system, . the 

 one used by day, the other illuminated to be conspicuous 

 at night. As early as 1658, John Baptista Porta, in 

 his u Natural Magick,&quot; entitled the last chapter of his 

 16th Book, &quot; By night we may make signs by fire.&quot; 



We have here a simple system of telegraphy, the 

 only examples afforded by the &quot;Century,&quot; of this 

 particular mode of correspondence. 



