Hi Dave- Try looking in   Bulletin of the Seismological Society of
America. Vol. 59, No. 1, pp. 183-227. February, 1969  or go to:
http://neic.usgs.gov/neis/seismology/history_seis.html to see what Ewing
did.
BTW- Dewey works in the same office as John Lahr- NEIC-Denver...Jim/UNLV
 
The Early History of Seismometry (to 1900) 
by 
James Dewey and Perry Byerly 

 
Abstract 
The earliest seismoscope was invented in 132 A.D., by Chang Hêng.
Seismoscopes of limited effectiveness were used by Bina and others in the
eighteenth century. The middle nineteenth century saw the invention by
Palmieri of a seismoscope to record the times of small earthquakes. 
A successful seismograph of low sensitivity was invented by Cecchi in
1875. British scientists at the College of Engineering, Tokyo,
independently built seismographs in the 1880's. The British in Japan made
many observations with their instruments and must be credited with first
demonstrating the value to seismology of seismographic devices. 
Von Rebeur-Paschwitz obtained the first recording of a teleseism in 1889.
In the next decade, investigators in Italy, Germany, and England studied
the waves from distant earthquakes and constructed the first teleseismic
travel-time charts. Wiechert introduced a seismometer with viscous
damping in 1898. 
Theory seems to have been neglected in the early development of the
seismograph. Theoretical studies of forced damped harmonic-oscillator
seismographs were presented by Perry and Ayrton, and Lippmann, but these
had little effect on the construction of seismographs. In the 1890's, the
importance of tilt was much debated. By 1900, many seismologists had
become convinced that the effect of tilting on seismograph response could
usually be neglected. 


On Mon, 31 Mar 2003 17:20:58 -0500 "David H. Youden" 
writes:
> All,
> 
> I have finally hit pay dirt in my quest for the original folded 
> pendulum 
> seismometer.
> 
> The original instrument of this type was built in 1882 by Dr James 
> Ewing. I 
> believe that Dr Ewing was in Tokyo at the time. His instrument used 
> a 
> common pendulum coupled to an inverted pendulum so as to decrease 
> the 
> stability of the common pendulum. It appears to me that this was a 
> two-axis 
> instrument. Dr Ewing referred to it as a "Duplex pendulum" 
> seismometer.
> 
> History has it that a number, possibly ten of these instruments were 
> placed 
> at sites in Northern California and Nevada during 1887-1888. 
> Seismographic 
> observatories at Berkeley and Mount Hamilton had duplex pendulum 
> seismometers.
> 
> Perhaps an avid researcher in California might be able to actually 
> find one 
> of these instruments.
> 
> Dr Ewing built many different seismometers and, along with Dr Thomas 
> Gray, 
> He seems to have been one of the founders of modern seismological 
> instrumentation.
> 
> The single axis instrument which I constructed is certainly not 
> identical 
> to the two-axis unit of Ewing, but it employs the same principals 
> and is, 
> in many ways similar to his duplex pendulum design.
> 
> My best to all,
> Dave...
> 
> __________________________________________________________
> 
> Public Seismic Network Mailing List (PSN-L)
> 
> To leave this list email PSN-L-REQUEST@.............. with 
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
> 






Hi Dave- Try looking in   Bulletin =
of the=20
Seismological Society of America. Vol. 59, No. 1, pp. 183-227. February=
,=20
1969  or go to: http://neic=
..usgs.gov/neis/seismology/history_seis.html to=20
see what Ewing did.
BTW- Dewey works in the same office as John Lahr-=20
NEIC-Denver...Jim/UNLV
 

The Early History of Seismometry (to =
1900)=20



by 
James Dewey and Perry Byerly=
=20

 
 

Abstract 
The earliest seismoscope was invented in 132 A.D=
.., by=20
  Chang H=EAng. Seismoscopes of limited effectiveness were used by Bina and=
 others=20
  in the eighteenth century. The middle nineteenth century saw the =
invention by=20
  Palmieri of a seismoscope to record the times of small earthquakes. 
  
A successful seismograph of low sensitivity was =
invented by=20
  Cecchi in 1875. British scientists at the College of Engineering, Tokyo,=
=20
  independently built seismographs in the 1880's. The British in Japan made=
 many=20
  observations with their instruments and must be credited with first=20
  demonstrating the value to seismology of seismographic devices. 
  
Von Rebeur-Paschwitz obtained the first recording of a=
=20
  teleseism in 1889. In the next decade, investigators in Italy, Germany, =
and=20
  England studied the waves from distant earthquakes and constructed the =
first=20
  teleseismic travel-time charts. Wiechert introduced a seismometer with =
viscous=20
  damping in 1898. 
  
Theory seems to have been neglected in the early =
development=20
  of the seismograph. Theoretical studies of forced damped harmonic-=
oscillator=20
  seismographs were presented by Perry and Ayrton, and Lippmann, but these =
had=20
  little effect on the construction of seismographs. In the 1890's, the=20
  importance of tilt was much debated. By 1900, many seismologists had =
become=20
  convinced that the effect of tilting on seismograph response could =
usually be=20
  neglected. 
 
 
=

On Mon, 31 Mar 2003 17:20:58 -0500 "David H. Youden" <dyouden@.........> writes:
>=
=20
All,
> 
> I have finally hit pay dirt in my quest for the =
original=20
folded 
> pendulum 
> seismometer.
> 
> The =
original=20
instrument of this type was built in 1882 by Dr James 
> Ewing. I >=20
believe that Dr Ewing was in Tokyo at the time. His instrument used 
>=
; a=20

> common pendulum coupled to an inverted pendulum so as to decrease=
=20

> the 
> stability of the common pendulum. It appears to me =
that=20
this was a 
> two-axis 
> instrument. Dr Ewing referred to it =
as a=20
"Duplex pendulum" 
> seismometer.
> 
> History has it =
that a=20
number, possibly ten of these instruments were 
> placed 
> at =
sites=20
in Northern California and Nevada during 1887-1888. 
> Seismographic=
=20

> observatories at Berkeley and Mount Hamilton had duplex pendulum=20

> seismometers.
> 
> Perhaps an avid researcher in =
California=20
might be able to actually 
> find one 
> of these=20
instruments.
> 
> Dr Ewing built many different seismometers =
and,=20
along with Dr Thomas 
> Gray, 
> He seems to have been one of =
the=20
founders of modern seismological 
> instrumentation.
> 
>=
 The=20
single axis instrument which I constructed is certainly not 
> =
identical=20

> to the two-axis unit of Ewing, but it employs the same principals=
=20

> and is, 
> in many ways similar to his duplex pendulum=20
design.
> 
> My best to all,
> Dave...
> 
>=20
__________________________________________________________
> 
>=
=20
Public Seismic Network Mailing List (PSN-L)
> 
> To leave this =
list=20
email PSN-L-REQUEST@.............. with=20

> the body of the message (first line only): unsubscribe
> See=
 http://www.seismicnet.com/=
maillist.html=20
for more information.
> 
>