[tz] netherland timezone UTC offset (0:19:32.13) history

[Eitan Adler]

(I am not currently subscribed, please keep me CCed)

Hi all,

I'm interested in some specific timezone history.  Specifically I'm
curious about the origin of 'STDOFF 0:19:32.13'.   Does anyone have an
authoritative source for where this is derived from?

Below is what I found so far:

1. In "NEWS" there is this entry:

===
   zic now accepts subsecond precision in expressions like
    00:19:32.13, which is approximately the legal time of the
    Netherlands from 1835 to 1937...
===

2. Wikipedia here  https://en.wikipedia.org/wiki/UTC%2B00:20 says
===
The reason for the specific offset of +0h 19m 32.13s was that the time
zone was centered on the mean solar time of the Westertoren (4° 53'
01.95" E Longitude), the tower of the Westerkerk church in Amsterdam.
===

but I can't find any reference to this specific offset in any of the
sources listed on Wikipedia. It is possible I missed the reference
though.
https://articles.adsabs.harvard.edu/pdf/1909Obs....32..297.
https://books.google.com/books?id=MbA-AQAAIAAJ&pg=PA75&printsec=frontcover&newbks=0&hl=en&ovso=1#v=onepage&q=netherl&f=false

3. I've seen several references that cite *to* wikipedia or tzdata,
but I haven't been able to find anything older.

(if this is off topic for the mailing list I apologize, this is the
best place I could find)

-- 
Eitan Adler