The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1878-08-07
STOP THAT NOISE F!

Mr.. H. D. WILSON'S PLAN TO DIMINISH THE
OBJECT Unable SOUND ON THE METRoPoL-
ITAN ELEVATED RAILROAD.
Among the many plans suggested for the
noise on the Metropolitan Elevated Railroad Is by
Mr.. H. Bowby Wilson. In speaking ofthe sounds pro-
duced on this road Mr. Wilson says the impact be.
tween the periphery OF tho wheels and the rali
causes o more less rapid vibration or the par.
tclcs Of metal composing them, ana these
Migratory motions OF the particles TO
creator or less extent impaired to the ties and
iron supports extending somewhat TO the longitudinal
aud transverse Orders. But tho chief and immediate
elect 10 creation of a wavy uEdulating motion
In the surrounding atmosphere These waves. which
sent of III all directions, are tho carriers OF sound.
its intensity varying nverseIy as the square OF the
distance from tho point Of inception On tho Elc-
waited road tho sound waves increase with the in.
creased vibrations OF the metal, and these arc In the
ratio OF more Than sledge hammer blows dealt VITA
incalcu labe rapidly by the numerous wheels OF the
engine ana cars, at o moderate ratio oil speed.
II haye, invited large number Of persons IN S'xih
avenue, Mr. Wilson says, 40 witness passing trains
tell me wfether tho noise came TO their cars and
their brains from the iron structure or from tho line
of rails direct and all have answered, Direct from
the raiis." The quantity and distribution of iron IN
the have little 10 90 In causing tho inten-
sity OF sound. On tho contrary the greater the
quantity OF IRON so much tho less Will be the noise
as there will be greater to absorb tho fugitive
yibra,ious mpared by tho rails. rho upright parts
OF the New York lines are cations of these v,bra-
tons, and SO far rs they have any elect upon the
noise carry IL into the earth
BREAKING SOUND WAVES.
1t follows thcn that as the waves oi sound are sent
of directly from tho rails and the wheels that the
remedy must be applied TO the seat oil the disease. ln
order 10 d.sporse these common carriers OF noise tho
effort DO TO break up The waves OF transmission
TINS is accomplished in pistol galleries and boiler
shops oy erecting double all and filing in the
with some non-vibrating substance, such as wool
feltng OIL sawdusL A simple lining OF thick letting
has been, found very elective Tor such purposes
"Actng upon this idea" Mr. Wilson says,i propose
to construct lane along the Two sides Of
tho structure, or what might prove better STILL
double lane tor each track to intercept the waves oil
TRANSMISSION aud break them up by dchectng them
in all directions and against escu other. 10
accom- sh this object propose TO construct the iane
OF sections OF convehicnt size for manufacture and
use which may approp DO termed phono deflec
tors-soupd dc1ectors. Those dencctors may be COM
posed OF ANY suitable matcriaI-snset galvanized
ron. or even papier 10 ache Between these sheets
propose inscr as the best available material COM
inon boiler loing, oil adequate thickness TO prevent
tho vibrations being taken up IRON the sound waves
and again impaired TO the atmosphere"
POSITION THE DKFLEcroRs.
The under elcctors be supper ca on the uange5
OF the girCcrs where that mole OF copstructo will
permit, and all oil them may be mado adjustable TO the
on tho New York Elevated Railroad, the tracks being
separate from each other aud WIDE distance apart
the collectors would require 70 conform 10 the pecu-
liarties OF the structure making double lane. Even
upon the Metropolitan Elevated ROAD double lane
might DO desirable, these lanes being continuous
their breadth or height bearing proper relation to
the distance they will occupy from tho line OF noise,
or impact betwacn INC wheels and rails The defect
TO be gained Is the destruction OF the sound waves,
and these will 20 thrown back forth and upward
by the aefcctors with rapdity 10 produce cqulb-
rum IN the partly enclosed spaces. Whom equilibrium
exists there no noise heard
NOISE THE TWO LINKS.
II has bucn asked why tho trains On tho New YORK
Elevated make oss noise III m those on tho Met.
ropoitan. The former company use lighter engines
four ,ons against Ten on The latterand they
run fifteen to twcuty miles an bour, nganst twen-
ynye 10 thirty, Wait I'll the heavier engines are run
ON tho Bowery and Third avenue ut equal rates OF
speed anu the result III tension engine makes
aivcu volume oi noisc at gwen speed what amount
Will q nitecn-ton engine SEND forth Is u sum
IN the rulo OF three Tor the dwolers
the Bowery and Third avenue 10 work out at
their leisure. It's Mr. Wsons nope by tho use OF his
ecctors to reduce The noise OF IRAN running thirty
miles an hour to OF running only ton, when
he thinks is ali that be reasonably expected.
Mr. Wilson also contends that us pDono -dcflectors
can be Ornamental us well as useful; that they
will not intercept the light from tho houses and shops,
and that those underneath tho track VIII serve good
purpose by preventing grease, clnders, SPIKES bolts
oven unucky men from ialiing into the streets
helaW