MARcH 28, 1884.] 
other, can be in operation. As the synchronous rota- 
tion continues, each circuit will be in turn closed 
through the single main-line wire in succession, and 
each twelve times in a rotation, and thirty-four times 
in a second. The frequency of successive closings 
of the same circuit is thus so great, that, in the fast- 
working Morse instrument, one closing at least will 
occur in even the shortest signal, so that no dot can 
be missed. 
The automatic synchronizing device consists’ in 
having three equi-distant segments in each set about 
twice as broad as the others, the segment next preced- 
ing each of these being idle. The relative positions 
of these broad segments are not the same in the two 
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sets; but, in the position corresponding to every broad 
segment of either set, there is, in the other set, an 
ordinary narrow segment connected with a grounded 
battery (the same battery serving, of course, for all 
three segments of each set). The broad segments 
are all grounded. The two distributers will be syn- 
chronous when the brush of one is on any one of its 
harrow-battery segments at the same instant that the 
brush of the other is on the idle segment next pre- 
ceding the broad one. If the synchronism is perfect, 
both brushes will pass off these segments at the same 
instant. If, however, the brush on the idle segment 
is ahead of such a synchronous position, it will pass 
on to the broad segmeut while yet the other brush 
is on the narrow-battery segment: a current through 
SCIENCE. © 
X, ¥.. {wo stations. 
brushes; /), driving-magnets; A!, regu- 
lating tuning-forks; A, magnets to keep 
tuning-forks in vibration; A’, auxiliary 
magnets to increase rate of vibration of 
forks, when the trailing-brushes are not 
rotating synchronously (an arrangement 
different from that given in text); 2, R', 
shunts to prevent sparking at contacts 
395 
the line and broad-segment contact to ground will 
ensue. This current excites a relay (located between 
the broad segment and the ground), which opens a 
local relay circuit (normally closed). As the arma- 
ture of this second relay comes sharply to its back- 
stop, it short-circuits the resistance-coil previously 
alluded to as being in the circuit of the fork-driving 
battery, and thus effects a slowing-down of the fork 
and distributer, as before described. As there are 
three broad segments to be touched in each revolu- 
tion, this synchronizing pulse may be sent thrice, 
twice, once, or not at all, as may be necessary, in 
either direction during each revolution. The two 
distributers may thus be kept within one-quarter of 
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the width of the narrow segments of each other; this 
corresponding to a synchronism of about 0.001 of a 
second, or about 0.002 of a revolution. 
Trenton natural history society. 
March 11. —W.S. Lee remarked on New Jersey as 
a paradise for the botanist, particularly commending 
the region about Trenton as one rich in rarities of 
plant-life. A certain hillside sloping to the south 
presents many spring flowers two weeks earlier than 
similar locations in even the same state; and several 
rare species grow there, among others Corydalis aurea 
and C.flavula. Other rare New-Jersey species men- 
tioned as found near Trenton were Fedia olitoria, 
Ellisia nyctelea, Onopordon acanthium, Potentilla, 
