New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1871-04-27
TIE PROBLEM OF SAFE TRAyEL-ELECTRIC
RAILWAY SIGNALS.

A series of working models illustrating the
practical operation Of system Of automatic electric rail-
way signals invented by Thomas S. Hail. is now on ex
hiblton at Roosevelt Hail. No. 954 Fourth-ave.. and
attracts much attention from electricians and railroad
managers. Tho system includes series OF devices by
which, through the agency Of electromagnetic, an
alarm signal ia displayed and bell rung whenever
switchrail is out OF place, drawbrdge open or train
il approaching embarrassing In each instance the
operation OF the signal is entirely automatic Inclosed
in o stout the point OF application to the main line
are several metallic rods connected by electrical conduc
tors with gavanc battery capable OF yielding constant
currents whenever the circuit completed The conduct
ing wires are carefully insulated and terminate at the
signalstation in the cores Of twoeecromagnets Ana-
ature directly above tho eleetr9nagets acts by means
OF lever upon signal stan and the capper OF an alarm
bell So delicate Is the adjusment OF the metallic rods
rail either side of the main line. or the withdrawal of
a bolt that secures drawbrdge, or the passage OF
train the track is sufficient to connect the poles OF
the battery aud to complete the circuit The flow OF the
yalizes the electromagnetic AT the signal station
bell and the raising OF colored signal. The bell
tnues to ring and the signal uped until the electric
or the replacement OF the bolt Of the drawbrdge. The
electromagnetic may be acted upon at distance Of
sounded at any distance from the point OF danger and
signals may DE displayed in either direction at such dis
tances 10 allow the sOppage OF a train
The apparatus is the same in principle for every APP
pcation although there are various devices ior operat
to switches, drawhrdges ana highway crossings ana IN
ment TO switchras double warning is given to the eye
OF the engineer and TO the of the swch-tender
wbenever switch a opened on the main line 20 as to
endanger passing trains. In the case Of drawbrdges
alarm signals continue in operation until tho draw Is
closed and the bolt which secures 1t is replaced by the
block system the wheels of passing train come in con-
with series Of delicate levers at intervals Of two
miles on the main line each of which closes electric
circuit, by means of which signal is brought into
sight two miles in advance OF the tram. AT
the time the pressure OF the wheels upon another
lever breaks the circuit and the signal at the station
which the train is passing falls by its own weight This
system, by which train registers its position two miles
In either direction Is designed to prevent collisions on
single double tracks In like manner, when train ia
mile and half distant from highway crossing, bell
may be rung and signal displayed by which teamsters
viii be given timely warning OF the approach Of the
train.
Two OF these applications-the attachment TO draw
bridges and switchrails been practically tested
the Morris and Essex and the NewYork and New Haven
Railway lines, and negotiations pending for the
introduction OF the entire system Of the leading
lines running West. Tie apparatus Is inexpensive, and
requires more attention in its operation than single
Ralyanic battery,