1883,] 327 { Houston. 
same direction, or any part in one direction and the remainder in the op- 
posite direction. 
“Tt would be difficult, on the eve of an important discovery like that we 
are discussing, to predict the extent and nature of the effect its practical in- 
troduction will have on the world at large; but this I think will appear 
evident, that the synchronous-multiplex telegraphic system will do for the 
most distant cities of our country, what the telephone has done for the in- 
habitants in the same city, or for those of neighboring cities, with, how- 
ever, this difference, that in the case of the synchronous system, a perma- 
nent record is obtained of all dispatches sent or received, while in the tele- 
phonic system of transmission there is none. 
“Without, however, secking to look further into the future, let us pass 
to the descriptions of the details of this remarkable invention. 
“The multiplex system differs radically from the quadruplex, which, as 
you are probably aware, is based on. the balancing of resistances, or the dif- 
ferential method. The multiplex system, on the contrary, is based on the 
synchronous rotation of two trailing contact arms which are connected to 
the ends of the line, one at cach end of the main line. Series of contacts, 
on the face of discs, swept by the trailing arms, are in electrical connection. 
with the various operators that desire to use the line. By the rotation of 
the arms, the main line is brought successively into electrical contact with 
such of the operators, and carried from one to another, and again given back 
to each successively, so rapidly, that before any of them can realize that 
he has been disconnected from the line, it is again given to him, so that 
the line is at his disposal, to the same extent as if he alone was using it. 
“The appliances whereby Mr. Delany maintains practically absolute syn- 
chronism in the revolving arms at each end of the line are of remarkable 
simplicity. A few of the contacts pefore referred to, as being placed on 
the face of the discs, are reserved for the maintenance of synchronism 
Some of these contacts are connected to a battery and others to cor- 
recting devices at each end of the line, while others are left open or un- 
connected with anything. If the synchronous rotation of the two arms 
is maintained, ‘no correcting impulses pass over the line, since, although 
one end thereof is in electrical connection with one of the batteries, the 
other end is on an unconnected segment, and the battery circuit: being 
open, no current flows ; should, however, the line at one end be brought 
in contact with a part of the dise, very slightly in advance of its position 
on the dise at the other end, then the battery is connected, and an electri 
cal impulse flows over the line, and slows the rotation of the arm. 
“The manner in which this correcting impulse is made a retarding one is 
as follows: the rotation of the trailing arm at each end of the line is main- 
tained by an electric magnetic device, invented by LaGour, of Copenha- 
gen, and termed by him a phonic-wheel. The rapidity of rotation of this 
wheel is dependent on the rapidity with which an electrical current tra- 
versing the coils of its electro-magnet, is made and broken. 
“The makes and breaks in the circuit of the motor-magnet of the phonic- 
