[Avodah] Gezeros in the BHMK

[Dov Kay]

>Then there is the question whether this half-an-hour is measured with 
>sha'os z'maniyos or sha'os shavos.  The Ohr Meir (by R. Meir Posen of 
>London) cites R. Hanoch Ehrentreu of Munich as paskening that it is a fixed 
>30 minutes, while my Rav paskened that it is a variable 30 minutes, ben 
>l'kula ben l'chumra.

>>>Bimchilas kevodo, that makes no sense.  The half-hour was to see the
>>>sun (or its shadow) move noticeably from its noon position.  The sun
>>>moves at exactly the same rate regardless of the day's length.  If on
>>>21-Jun the shadow reaches a certain point on the BHMK wall at exactly
>>>30 minutes past noon, then on 21-Dec it will also reach that point at
>>>exactly 30 minutes past noon, and not a moment earlier.

Astronomy is not my strong point, but I find it useful to compare the wall 
used in the BHMK to measure the 1/2 hour to a sundial.  It seems to me that 
the hour markings shown on a sundial do not denote fixed 60min hours, but 
seasonal hours.  In other words, the first shadow of the day will begin to 
appear at sunrise at the point on the sundial denoted by the 6:00am marking 
and the last shadow will vanish at sunset at the point on the sundial 
denoted by the 6:00pm marking.  Obviously, the real time which elapses 
between the "6:00am" and "6:00pm" will fluctuate throughout the year.  
Therefore, if we put a mark on the sundial to denote 12:30pm at the equinox, 
the time elapsing from noon until the sun shadow reaches that mark in the 
middle of summer will be longer than a fixed 30 minutes.  So to in the BHMK.

It seems from the Gemara in Yoma 28b, which discusses this topic, that the 
1/2 hour added from noon in the BHMK was based purely on observation of the 
shadow which appeared on the sloped walls, which justifies the p'sak I 
received from from the Rosh Kollel in Melbourne.

I assume that Dayan Ehrentreu's sevara was that the time added to avoid 
error in bringing the tamid too early should logically be constant, as with 
the 1/2 hour prohibition on doing melacha before bedikas chometz, KS, etc.  
However, I don't think that this is consistent with the sugya in Yoma.

I should point out that I have never actually seen a sundial in use and all 
this is based on my understanding of how it should work (isn't this typical 
of much on Avodah/Areivim?!).  Please let me know where I have gone wrong.  
After all I now live in England, where the sun seldom shines, but I do 
remember the sun from my youth in Australia!

On your more fundamental question as to whether the added 1/2 hour in the 
BHMK was a gezera, its seems from the sugya in Yoma that it was not a formal 
gezera but merely a precaution, but I have not had a chance to see what the 
Rishonim say about it.

A gut Erev Shabbos
Dov Kay
Manchester, UK

_________________________________________________________________
Txt a lot? Get Messenger FREE on your mobile. 
https://livemessenger.mobile.uk.msn.com/