RADIOTELEGRAPH Y—FLEMING. a rq 
number of impulses per second, each of which sets up in it free 
electrical oscillations of one definite period. 
A discharge composed of a single pair of metal plates with inter- 
posed separating paper ring has been devised and employed by Von 
Lepel. In this case the plates are connected to the terminals of a 
high-voltage direct-current dynamo, and are shunted by a circuit 
having inductance and capacity, one of the plates being also connected 
to an antenna and the other to a balancing capacity. 
These dischargers, however, have not stood the test of prolonged 
practical use, and we can not say therefore that they are comparable 
in value for telegraphic purposes 
with the well-proved inventions 
of Mr. Marconi. 
In connection with spark teleg- 
raphy it has been clearly seen, 
lately, that much can be done by 
attention to details of construc- 
tion to increase the number of 
oscillations in each wave train in 
the case of spark apparatus, in 
other words, to lessen the damp- 
ing by obviating energy losses in 
all parts of the apparatus. It is 
not a matter of indifference what 
kind of glass we use in Leyden 
jars or what form of stranded 
wire we employ in oscillation 
transformers, or type of spark 
discharger. By appropriate selec- 
tion of apparatus, we can con- SS 
siderably increase the number of Plan of Copper Flanged Plate. 
oscillations in damped trains of F'6- 118. Plan and section showing por- 
small amplitude, and therefore Sci Nia Saba 
increase the possibilities of utilizing the principle of resonance. 
Before leaving the subject of the antenna we may notice some 
recent improvements in directive antennae, that is, in devices for 
more or less confining the radiation to one direction, and for locating 
the position of the sending station. 
In a previous discourse explanations were given of the property 
of a closed or partly closed antenna of radiating more in some direc- 
tions than others, and the action of Marconi’s bent antenna was 
described. Two other inventors, Messrs. Bellini and Tosi, have taken 
advantage of this fact to construct antenne of a very interesting 
character. They erect an antenna consisting of two wires, each bent 
ttre seme nen ewe Ban wee, wm nee nw wee anne 
